Page 6.26
Problems with Advice
Return to WhittsFlying
Contents
Crabs, Kicks and Slips to Landings; ...Turns
about a Point and S-Turns; ...Critical Angle of
Attack; ...Pitch; ...Altimeter
Setting Change; ...Altimeter Indication; ...Checkride
Skills; ...Performance?; ...Start
of Landing; ...Finding Landing Attitude on the
Ground; ...On Moving the Yoke; ...Another
Related Subject; ...Herb's Opinion on His Landings;
...Advice to a Student on Landing; ...More
Notes to Herb; ...A Plea for Help; ...Night
Flare; ...Using Rudder; ...Flare;
…The Ball; …Manifold
Pressure; …
(Parenthetical remarks in italic by Gene)
Crabs,
Kicks and Slips to Landings
The Problem
Ken Wiebe wrote:
This is a great thread. I've been wrestling (mentally) with slips, mostly having
to do with crosswind landings. The side- vs. forward-slip references were
confusing me, but now I think I'm getting it.
Awhile back there was a thread that dealt more directly with crosswind landing
techniques, and naturally it got into sideslips. But one thing that confused me
in that thread was crabbing, and references to the comfort of passengers,
coordinated vs. uncoordinated, etc. Can we throw crabbing into the mix for this
thread?
I think I understand how crabbing by itself can be a crosswind correction
technique: Nose points into wind, ground track is at an angle to longitudinal
axis. And this is all done by deflecting the rudder, and rudder alone, correct?
It seems like all slips are "uncoordinated" - but what about crabbing?
I think I remember the x-wind landing thread where crabbing was referred to as
"coordinated". Is that true? And, what does the ball do in these
scenarios (sideslip, forward slip, crabbing)? Are there only two ways you can or
should correct for x-wind? (I.e., the two main techniques used for the approach
for crosswind landings - crabbing and side slipping) What if you're not on final
and you need to correct?
Thanks in advance. In replies, please state what the ball is doing and whether
it's considered coordinated. Also maybe discuss this pax comfort issue too.
Ken Wiebe
The Advice:
Crabbing is not what you do. Crabbing is what the wind does to you. When you
"crab" to a landing you merely fly the airplane along. The wind blows
you sideways as you go forward so your actual track over the ground is not quite
in the direction your nose is pointed. Rather like rowing a boat across the
river. If you want to go directly across, you had best point your nose upstream
a bit!
When you "crab" down final you are merely flying in level flight and
adjusting your heading to make the desired ground track, exactly as you do with
flying cross country. It is more comfortable for the passengers because it IS
coordinated flight. You are merely accepting the drift caused by the wind.
The problem with crabbing all the way to a landing, is that, when you land you
are going one way and your nose is pointed the other. This makes for some
strange and abrupt heading changes when (before) you touch down! :-)
Fortunately, if you have a nose wheel, and have it well in the air as you
should, when you touch down the abrupt heading change is in the correct
direction for roll out. This is the standard crosswind landing technique for
Ercoupes and Boeing 747's. :-) The approach is comfortable for the passengers,
but the touchdown can give you a bit of a jerk! (Unless wing-low into wind
corrects for drift when nose is straight with the runway.)
The ideal crosswind landing is to continue the crab, that you have been flying
with all the way, whether you realized it or not, until you are about to land
and then transition to a slip such that your sideways travel in the slip exactly
matches the wind velocity. That way you wheels are pointed in the correct
direction before you place them solidly onto the runway and there are no sudden
changes at touchdown, making the whole process smoother and less alarming to
pilot and pax. (Exact timing required but rarely achieved.)
How far away from touchdown should you make this transition? Let your conscience
be your guide. Some teach the "kick-out" method where you make the
transition just as your wheels are about to touch. The problem with this method
is that it requires excruciatingly accurate timing. I find that my reflexes
aren't up to that kind of timing consistently as I get older, and therefore
prefer to transition from the crab to the slip far enough from touchdown to have
the slip stabilized before I need it at ground contact. How far out is that?
Depends. :-)
I recommend that student pilots begin to establish the slip as soon as the roll
out of the turn from base to final approach. That gives them lots of time to
play with the slip and get everything stabilized before they have to roundout
and flare. Just be careful not to let the slip go when you start the roundout
and flare!
Highflyer
Turns
about a Point and S-Turns
The Problem
C. TASK: TURNS AROUND A POINT.
Objective 5:
Applies adequate wind-drift correction to track a constant radius circle around
the selected reference point with a
bank of approximately 45 degrees at the steepest point in the turn.
Advice:
From that, one would gather that selecting an 'approximate' bank angle of 45
degrees simply requires choosing a
distance from the point that calls for such a bank angle on the downwind turn.
At least, that was how I was taught!
-Ryan
Advice:
At least one of my CFIs has indicated to ENTER
on a 45-degree bank -- regardless of the wind. Another had me/let me go
shallower. The MATH says that with NO WIND
the whole thing will work at ANY CONSTANT bank -- say 30
degrees. And that if you have for each 10% wind speed relative to airspeed (10
kts for a typical 100 kt light trainer to keep the math easy) you need about 5
more degrees or less if you are trying to maintain the same arc as
the 30 degree no-wind circle:
10% == 25-35 degrees
20% == 20-40 degrees
30% == 15-45 degrees
40% == 10-50 degrees
The PTS that I read said, "a maximum of 45 degrees" but did NOT
give a MINIMUM, nor did it give a maximum or minimum
radius for the turn.
There is also the "just make a circle" school of thought.
What is the truth? The PTS as written? Created on the spot by the DE at
checkride?
Herb Martin
(student pilot)
Advice:
From that, one would gather that selecting an 'approximate' bank angle of 45
degrees simply requires choosing a
distance from the point that calls for such a bank angle on the downwind turn.
At least, that was how I was taught!
-Ryan
Advice
Applies adequate wind-drift correction to track a constant radius circle around
the selected reference point with a bank of approximately 45 [degrees] at the
steepest point in the turn. …and since you enter on the downwind, which is the
part of the turn which requires the steepest bank, that would seem to require
that you enter at a bank of "approximately 45 degrees". My
instructor is also big on the "pick 4 ground reference points to hit as you
make your circle" thing, and that's not in the PTS at all.
Ben Jackson
Advice:
If I remember correctly, you should not exceed 45 degrees of bank. 45 degrees of
bank is considered a steep turn for a PPL certificate, and nowhere on the
checkride will you be asked to demonstrate more than that. (Commercial is
different)
If possible, pick out an intersection of two roads. Find 4 points along these
roads that are equal distance from the actual intersection. While flying over
these 4 points, keep planning ahead to the next point by adjusting bank to
compensate for the wind. These points will be somewhere between 1/4 to 1/2 mile
from the intersection. As you can see, you really won't be looking at the
point you're flying around, but at the 4 reference points around that point...and
always planning your flight for the next point. Wings should never become level,
but adjusted constantly to compensate for wind so that a perfect (symmetrical)
flight path is flown around the point. (remember to hold a constant altitude
also) <g> Best,
BJ
I can tell you that my DE of many years ago wanted to see "fluid and total
control" of the airplane while doing the turn about point. The bank angle
didn't matter as it will vary as you complete the turn and how much wind
correction it needed. I would start with a standard rate turn and then
"vary" the bank angle depending on wind and location in the turn. The
most important thing here is coordinated flight with proper inputs, altitude,
airspeed and distance from reference point.
In my opinion, the best way is to determine the wind direction and enter from
the downwind to establish bank angle then you know you will have to shallow the
bank angle on the upwind part to "stretch" the circle and then return
to your original bank angle to finish. Don't get hung up on a
"particular" bank angle...use what works at the time. Don't look
inside the airplane too much, mentally/visually "draw" a circle around
the reference point and then just fly the airplane over that imagined circle
using proper inputs. Good luck and hope this helps...--
Terry.
..
Redux
I agree with (pretty much) everything everyone was kind enough to offer.
Main points: Smooth, coordinated control of the aircraft while turning a CIRCLE
around the point by crossing 4 (or more) equidistant points. It is EASIER
to use a SMALLER bank. If you don't know what your MAXIMUM
bank will be you cannot (in theory) PICK an ENTRY
POINT that will be on the RADIUS of the circle.
The SECOND PTS reference that I checked said,
"approximately 45 degrees at the steepest point in the turn" as one
poster replied here. Another poster reiterated the "45 degree MAXIMUM
turn on the private exam' idea, that I had seen.
I get all of the above but if you pick your point based on a 30 degree entry,
you cannot turn that one with a 45 and still get a circle.
Herb Martin
Critical Angle
of Attack
Problem
Does the critical AOA change when the CG moves forward?
David Moran
Answers
That's an excellent question!
The short answer is that no, it does not. Critical AOA is only a function of the
shape of the wing (including things like whether flaps are deployed).
What moving the CG forward does do, however, is increase the *airspeed* at which
you stall. As the CG moves forward, the tailplane has to generate more
down-force to keep the airplane in balance. This results in the main wing having
to produce more lift to keep the aircraft in the air, and thus requires a higher
airspeed for a given AOA.
Roy Smith, CFI-ASE-IA
More:
The critical AOA never changes in any given airplane. But you can reach this
critical angle through several ways: changing pitch, airspeed, g-load, CG
position, whatever. The critical AOA is always at the maximum coefficient of
lift, which is given for any aircraft.
So, the AOA at which an aircraft stalls stays the same (otherwise all AOA
indicators would be useless), but the speed at which the stall occurs changes
with lots of factors.
Patrick
Pitch
Problem
That's only partially true. AOA is the difference between your pitch
attitude(*) and your flight path. You really can only perceive your pitch
attitude by looking out the window to see where the nose is pointing.
On an ILS, with a -3 degree flight path, your pitch attitude is going to be 3
degrees lower for the same AOA your airspeed would give you in level flight. On
a typical VFR descent, you're on about a -6 degree flight path, so your pitch
attitude will be even lower for the same AOA. The extreme case would be a spin,
where your pitch attitude is nearly vertical, but you are still stalled because
the AOA is too high.
Most people are used to stalling by shoving the nose way up in the air while
trying to maintain altitude. That's because that's the way the maneuver is
taught to meet PTS demonstration requirements. Unfortunately, I think all that
teaches people is that you can't stall when you can see the ground out the front
window.
But, a more realistic demonstration of an approach-to-landing stall would be to
set up constant 6 degree descent at 1.2 VS0 (for most light planes, that's about
a 700 FPM descent). If you're lucky, you might find a small airport near you
with a 6-degree VASI on a non-instrument runway (check the AFD). If you can
intercept the VASI 5-10 miles out and track that during this exercise, that
should work fine. Alternatively, try and intercept one of those mythical false
ILS glide slopes we're always talking about on r.a.ifr :-)
You're probably looking at something like 1300 RPM and full flaps (like you
would be on short final). You will have a distinct nose-down pitch attitude.
Now, reduce power to idle and slowly pitch up just enough to bleed off airspeed
as you keep the descent rate constant. You should be able to get down close to
VS0 like this.
Once you've got that stable, low airspeed, high rate of descent glide set up,
pitch up at somewhat faster pitch rate. You should stall, and do so with a
significantly lower pitch attitude than you do on a normal PTS-style stall demo.
This is what it really looks like when somebody is trying to stretch a glide to
make the runway without adding power.
It would be really cool to try this in something like a Mooney with speed brakes
deployed! What's the glide ratio with gear down, full flaps, speed brakes, and
idle power?
(*) To be more precise, it's the difference between (pitch attitude + angle of
incidence of the wing) and your flight path. But, since angle of incidence is
constant (on most airplanes!), you can pretty much ignore it
for these purposes.--
Roy Smith, CFI-ASE-IA
You might want to add here that referencing a specific view from the airplane
to critical angle of attack isn't the best way to approach this, as you can
exceed critical angle of attack and stall the wing in ANY flight attitude;
straight up; straight down; or upside down. The view of course will be different
in each case. In my opinion at least, referencing AOA with a specific view from
the cockpit can be misleading to an overall understanding of how critical AOA
and not airspeed should be the reference for stall.--
Dudley Henriques
Altimeter
Setting Change
Problem
If a pilot changes the altimeter setting from 30.11 to 29.96, what is the
approximate change in indication?
Altimeter will indicate .15" Hg higher.
Altimeter will indicate 150 feet higher.
Altimeter will indicate 150 feet lower. <- correct answer--
Sorry, but this is really confusing me. If the pressure is 0.15'' less, then
surely you have gained 150ft since pressure drops as altitude is gained?
David
Why?
Pressure stayed the same, you just told the altimeter the reference was
lower.
Robert Gary
#2
[I may have been redundant below, but saying it two or three ways might give you
a method that makes the MOST SENSE to you.]
Ok, the easy part: 1 inch Hg is about 1000 feet. So, 0.15 inches is going to be EITHER
150 up or down, right? You are going to hear "High to Low, Look out
below" from others trying to help you -- but this didn't really do it for
me although once you understand THIS issue, it WILL
help you keep it straight.
Look out below, means that the INDICATED altitude will be
lower than the TRUE altitude (people below might be in
danger even though you THINK you are high ENOUGH.)
So if YOU CHANGE from HIGH
setting to LOW setting, you will INDICATE
less than before.
This is a HIGH->LOW so it is a DECREASE
-- or 150 feet in altitude [indicated --> true]
[Here is another way to UNDERSTAND the issue -- but it is
a terrible way to REMEMBER it so you might want to re-read
what is above after you either "get this" or "decide it doesn't
help": When your altimeter is set to a LOWER VALUE,
you are moving the BASE pressure (sea level) UP
and this is LESS of a difference between that base and the
current altitude setting pressure. So your FEET read lower
when your PRESSURE setting is LOWER.]
Another thing to be careful about, SOME of the questions
will give you "true altitude read High/Low" while some like this one
will be based on "indicated altitude" (as yours above is.) BE
CAREFUL that you are reading it correctly.
The PRESSURE you are setting is the BASE,
and as you CLIMB the pressure gets lower. The ALTIMETER
really reads the DIFFERENCE between these two pressures:
Current altitude and the BASE sea level pressures. So a
lower base (pressure, not altitude) gives LESS DIFFERENCE as
the altitude continues to lower the pressure.
Since ALTITUDE gives a LOWER PRESSURE,
reducing the pressure of the BASE gives a SMALLER
DIFFERENCE ...a smaller difference between the Sea Level Base pressure
and the Current Altitude Pressure.
Herb Martin
If you start over-thinking it you'll get mixed up. It's fine to understand the
ins and outs, but in the air just think, "high to low, look out
below." Going from "high temp/high pressure". to low means
trouble - trouble means you're closer to the ground (AGL) than you think. What
makes you think that? Indicated altitude.
So, the IA is higher, but the True altitude is lower. When you take into account
the fact that you'll be keeping the plane at the same indicated altitude
throughout, you're true altitude is now getting less and less.--
Charles Oppermann,
It's a simple rule: if the numbers in the pressure window get lower, so does
the indicated altitude!
Patrick
Do you know what a 'slinky' is? I hope so cause' if you don't you won't get my
drift. Imagine the slinky is the atmosphere. Attach little tags to the
slinky that correspond to different pressure levels. So at the bottom of the
slinky I attach a tag that says "29.92", and above that (since the
pressure will be lower) I attach a tag that says "29.01, etc. Note that the
pressure level of 29.01 will always be above 29.92 because pressure decreases
with altitude.
After you have attached all your tags stretch the slinky. All of the pressure
levels rise. This corresponds to a hot day when the atmosphere has expanded. The
altitude at which you will find 29.92 changes from day to day depending upon
temperature and pressure. With me so far?
Now there you are at 5000' flying along with 29.92 in the little window on the
altimeter (the Kollsman window) and the temperature drops. This causes the
slinky to contract, which causes the 29.92 level to drop lower. This has all
happened while you are flying along fat, dumb, and happy as you chase the needle
on the altimeter to make it say 5000'. You have no idea that the temperature has
dropped, or that the pressure has changed. What has happened?
Well, the pressure level that you were using to measure off of--29.92--moved
downwards because the atmosphere shrunk. You chased the needle to make it say
5000' and this put you closer to mother earth, right? But you think "I am
still at 5000', why does that mountain look so high?"
As has been said, the altimeter measures or references off of whatever you put
into the kollsman window. It tells you how high you are above that level. Keep
in mind that the pressure levels move up and down and that you are measuring
your distance above that level and I think you will have your answer.
In your example the pilot changed the level which s/he was referencing off of.
That level is physically higher so, if I were standing at the top of a 1000'
tower and were measuring with my hand-held altimeter and I was first measuring
the distance between me and the 30.11 level and then changed the setting to
measure between me and the 29.96 (higher) level the altimeter thinks the
distance has shrunk, right? So it will measure lower.
Antonio
Altimeter
Indication
Second Problem
Which condition would cause the altimeter to indicate a lower
altitude than true altitude?
A Air temperature warmer than standard.
B Atmospheric pressure lower than standard.
C Air temperature lower than standard.
I chose "C" because the altimeter reads a higher altitude in dense air
(cool air), so if the temperature was lowered, the air would be more dense and
the altimeter would feel closer to the ground?
David
The answer is 'A'. The word "indicate" in the question is the one
to watch out for. The altimeter is *indicating* you are lower than you actually
are. Another way to say that is: your true altitude is higher than what is
indicated on the altimeter.
You can remember all of this by the old mnemonic: "High to low, lookout
below. Low to high, you're in the sky". When you go from a high to a low
you need to 'lookout below' because you are closer to the ground than the
altimeter says you are--that is-- the altimeter is *indicating * higher.
The question asks, "What would cause the altimeter to *indicate*
lower..." which can be tricky. The altimeter will *indicate* you are lower
than you actually are when the temperature or pressure has risen. "Low to
high you're in the sky" means that when the temperature rises your
altimeter will *indicate* that you are lower than you actually are.
Antonio
Checkride Skills
The Problem
I'm supposed to take my PPL checkride on Sunday and seem to have developed
Soft-Field-Landing-Block. Even my instructor is becoming a little frustrated as
I had no problems with these a month ago. I am flying a Warrior and seem
to be flaring too early. I guess I'm nervous about a prop strike. Does anyone
have any tips?
The Advice
Just pretend it's a normal landing...BUT...after touch
down keep the nose wheel off the ground as long as possible by keeping the yoke
in your lap during the whole roll out. That's it. (Add a bit of power
if you haven't kept some on and remove the flaps right away this will help the
elevators maintain authority..) Oh and just for looks you may want to add a
very small touch of power just before the mains touch. The DE isn't looking for
perfection, just that you know the procedures and get them in the ballpark.
Personally, I can never get the "add a touch of power" thing. I never
seem to find the happy medium and usually make the plane begin a balloon or if
it doesn't balloon it distracts me enough not to flare properly. I just do a
normal landing and keep the nose wheel off the ground as long as possible
without using the brakes.
Kobra
Ah, the pre-checkride block. Take an instructor with you and low approaches
flying just inches above the surface. You'll learn what power setting will keep
you flying....anything less than that will put you on the runway. Don't worry
man, come the big day you'll surprise even yourself.
Rodney
One of many reasons for doing slow flight and MCA is get ready for landings in
general and slow flight in particular. Trick is to land as low and as slow as
possible with minimum descent rate. This may very well mean landing with power,
depending on the airplane.
Watson
Given a choice, I would rather be sure that you are ready for the check ride
rather than make you take the check ride just because you are scheduled for it.
If soft field landings are suddenly a problem for you, then I would hope that
you can get them worked out before Sunday.
Have you tried looking further down the runway?
C. J. Campbell
Get your instructor to take you to a grass strip. Works for my students.
Although somewhat harder to find, a runway with slushy snow works even better.
PD
That doesn't really sound like a soft field landing problem but a regular
landing problem.
Unknown
I do something a little bit different (at least I think it's different) when I
teach soft field landings. I try to focus a bit more on the mental state than
the physical motions. After discussing the purpose of the soft landing and the
objectives, I tell my student that I really like them -- that's not just a PTS
task we have to get through. Instead, it's the landing that really makes you
into a pilot.
Think about a typical landing. Roundout, pull power back, hold nose up, =hoping=
that you did it right and =waiting= for the airplane to land itself. Many of us,
me included, have found ourselves more passengers to the whim of the airplane
than as PIC telling it what to do. (Not a bad way to think of it.) And we
can get away with that most of the time.
In a soft field landing, like with a significant x-wind, we =have to= fly the
airplane to the ground and on the ground. When the "touch of power"
results in a balloon or excessive airspeed, it's because we haven't yet
learned how to use the throttle to control our touchdown.
Although doing soft field landings on a 12,000 paved runway hardly simulates the
real thing; it does have its advantages. One of the demos I do for a student is
to do a soft-field landing, keep rolling
at least 1000' down the runway and take off again, all without ever letting the
nosewheel touch. Just to show the kind of control you can get when you develop
feel for pitch and power. My student can eventually do this himself.-
Mark Kolber
Try carrying some power (not sure of the best setting in the Warrior) all the
way in until the mains kiss the runway, and then remove the power. You basically
fly the a/c onto the runway. Full flap about half way down final.
Gary Spicer
I agree with everyone else...but the prop strike question bothers me. If you
are not concerned about a prop strike during a normal landing (which should be
on the mains, with the nosewheel coming down last), why would you get a prop
strike with propeller discharge air over the horizontal stabilizer
keeping the nosewheel well clear of the surface?
Bob Gardner
When I was a student, my problem with soft-field landings was in fact flaring
too late! My normal landings used to have a squarer flare than they ought to,
and while I could get away with this most of the time, for soft-fields, the
extra power meant that I'd either balloon out of ground effect when I tried my
late round-out, or that I'd not get the nose high enough before we'd touch. Starting
the pull back much higher and trusting in the extra power and ground effect to
hold the plane in the air produced a much more nose-high attitude and allowed
the plane to settle very, very gently on to the ground as required. It
made an amazing change, and once my CFI had identified this as the problem, my
soft-field woes went away.
Mike Granby
I don't think it's been mentioned (though Mark implied it) but theoretically
in a soft field landing you have an endlessly long runway. This means that you
have the entire length of the runway to stabilize and set her down nose high on
the backside of the power curve.
My advice: Take your time and use up the whole runway. Fly a few inches off of
the ground and don't let it touch down. When it wants to settle, add a little
power and increase backpressure. If it starts to rise, release backpressure (If
releasing back-pressure means letting the yoke move forward...DON'T)
and/or reduce power. Keep her flying 'til she doesn't want to fly anymore! Once
down, hold the nose in the air 'til it comes down on its own.
Antonio
Performance?
Problem
Where can I find the equations or a sample spreadsheet that will provide the
calculations for ground roll, landing, and takeoff distances (over 50' obstacle
too) especially for a PIPER Warrior and Archer.
Barring that, how can I get the TABULAR DATA that was used
to create the POH tables for these items? Some manufacturers provide the
tabular form, but Piper gives the graphical tables.
Herb Martin
Advice
The raw data contains so many possibilities for inaccuracy that what you suggest
would be a waste of time (in my humble opinion): the temperature you use is
probably not the temperature at the runway surface; if you are typical, you
don't know the aircraft weight within 100 pounds; if wind enters into your
calculations you do not know it with any degree of accuracy; your airplane and
its engine are not as young as those used by factory engineers. Use the
numbers in the manual and add fifty percent to all answers. (Always
move POH numbers in the most conservative (read safe) direction)
Never rely on book performance figures.
Bob Gardner
Problem
Start
of Landing
How I was taught to fly the pattern (from memory then I will check my notes):
PA-28-161 Warrior II
Left downwind for 18 favored runway for GTU (Georgetown Municipal, just north of
Austin.) 5000’ nice place. Also seldom used 3800’ 11/29.
GW
Nice to have runway with cardinal headings. You should have noted by now that
'The Sum of the Digits' are all equal in the pattern regardless of the runway
number 180=9, 090 = 9, 270 =9 360 =9 or on the other runway 110 = 2, 200 =2, 290
= 11=2, and 020 =2. The 45s work the same as well but not as useful.
When you enter a no-wind 45 entry for a left pattern your runway heading will be
on the left rear of your heading indicator. When entering on a right 45 the
runway heading will be on your right rear.
Helps making 45 entries to strange fields. Use E6-B or HI to see this.
HM
Get AWOS, announce loc, alt, landing 18.
GW
If most aircraft come in using the same call-up points and even altitudes, try
this. Report as being, "One north (reference point) at two-thousand
three-hundred (2,300) planning left 45, 18 Georgetown. This gives you a safety
margin over those who always fly 2000, 2500 etc. In a low wing aircraft, it is
somewhat safer to come into the pattern a bit low 1600 AGL on the 45 because
your visibility it better up than down for traffic. Be at pattern altitude on
downwind.
HM
Come in from the SE at pattern altitude 1000’ AGL (1800 MSL), 2200 RPM Max (on
notes but not emphasized) Announce turning left downwind.
GW
Always trim for level, hands-off flight on downwind. Note: The amount of trim
required so that you can get close to proper setting in one move and then make
small changes. Counting buttons on trim wheel is one way.
HM
Abeam the numbers throttle back to 1500, 1 notch flaps (unless extending
downwind for traffic etc.)
PITCH HALF SKY/HALF GROUND (This is emphasized.)
GW
Have you noticed that when reducing to 1500 that as the plane slows you must
bump it up a bit? Consider reducing power to between 16/1700 so that
deceleration of plane will cause rpm drop to 1500. Anticipation!
Some airports (mine) prefer that no altitude be lost until turning base for
noise abatement. What you do to the trim on power reduction will be different
then.
HM
POH: Approach speed 73 kts
POH: Final approach speed 63 kts
(My notes from instructor say "63 kts" throughout, I asked and wrote
that on them but this is not emphasized. Picture is the KEY.)
GW
Too bad instructor did not explain about Vref at this point or later on the
ground. The POH speeds are all at gross weights. When you are below gross
weight, as you usually are without a third person in the plane, you should
figure your speeds for landings based on the percentage your present landing
weight is less than gross weight and reduce you approach speeds accordingly.
Very simple to do but have instructor work it out with you for his benefit.
HM
When on 45-degree angle over left shoulder turn left for base and announce.
GW
For some reason the recent FAA preference recommends against the use of the
'key' position. Don't tell examiner what/why you do as most pilots do as well.
The interesting difference between Piper/Cessna is that addition of flaps in
Pipers require very little trim change, whereas Cessna pilots are always
trimming. Recent Cessna Training Centers are using a system that allows patterns
to be flow much as do Pipers. Works either way.
HM
If altitude is ‘right’, add 2nd notch flaps. (I know that if I am real low I
should NOT remove the 1st but
add power.) Probably should be 600-700’ but I had to think that out and it is
not emphasized.
EW
Very important that you become proficient with making corrections in your glide
path. When low, the worst thing to do is adding a bit of power. At altitude, put
the plane into a landing approach configuration and then do nothing but add 200
rpm. Tell me what happens as opposed to what you 'think' happens.
There is only ONE safe option when correcting for being low.
HM
POWER I thought this was it. I didn't say adjust
pitch/speed but had that in mind as part of the adding power.
GW
FULL POWER with forward pressure to hold constant airspeed
'timed' to intercept glide path. By
'timed' I mean you do it from ten to thirty seconds as you estimate needed to
attain preferred glide path.
GW
When high you have three options. They are? Proper sequence? Why?
HM
I don't KNOW the answer:
If I am on BEST glide, then LIFTING
the nose to slow down will shorten the path. I can reduce power of course and
add flaps. I can also SLIP -- I have practiced a slip
twice.
(Missing sequence)
HM
Turn left final and announce landing. Cut power about here "when landing is
assured" and add last flaps. Left hand on yoke, right hand on throttle.
GW
You never mention carburetor heat? Why? When? What do you do if engine dies at
400' on final?
See what instructor comes up with. Try at altitude and then at airport.
HM
My notes from instructor indicate about 300-500’ AGL at 1/4 mile (not
emphasized.)
GW
Variable because of headwind velocity. In any wind over 15 knots don't be
concerned about being high on approach.
HM
Make sure the aiming point is NOT rising or falling in the
windscreen.
GW
I would be more concerned as to having a stabilized approach at constant
airspeed. Airspeed trimmed for handsoff flight will maintain a constant sight
picture.
HM
[From here I don’t have "instructions" from my CFIs (just stuff I
have read), but they have SHOWN me examples. It’s this point where
communication gets ‘weak’.]
Over the numbers about wing span high BREAK glide to level
over runway, focus ahead mostly, as the plane begins to settle bring the nose up
to cover the far end of the runway.
GW
Your BREAK is more commonly called the round-out where to
attempt to level the aircraft off with the wheels about hip high. Airspeed here
is critical, this is the only way you can develop the site picture and yoke
movement pattern than will allow a smooth roundout without a balloon. Because of
the
long low wing you will balloon if too fast. Go-around as your first and best
option. The major variable that makes consistency difficult is changes in air
temperature and density.
What you wait for during the roundout is as the plane slows in level flight you
will feel an elevator-like sink as a signal to begin raising the nose.
The worst thing you can do is trying to keep the runway in sight. A landing is
an act of faith helped by what you see to each side of the nose. I presume you
played some football. The linemen have learned to 'split' their peripheral
vision between the ball and the guy in front.
The pilot must split his vision to each side of the aircraft nose. There is a
horizon line that measures the rise and fall of the aircraft. If the horizon
line falls it means that the aircraft is rising. When the line rises the
aircraft is falling. It is acceptable to stop moving the yoke back up to stop or
slow. It is a major NO to move the yoke forward however
slightly. Go-around!
The worst thing that could happen to you is to salvage a poor flare to a good
landing. This one time success makes you believe that the next and perhaps all
poor approaches can be salvaged. Not so! Learn to make landings as a student.
Salvaged landings are reserved for emergencies not practice.
What you should be trying to do in the flare is to keep that line still, neither
rising nor falling as you 'tilt' the nose up for touchdown on the main landing
gear. The gear designed to absorb considerable impact. Important that you do not
allow the shock of landing to move the yoke forward so the nosewheel hits hard
as well.
Perfect landings are lucky. Good landings are occasional. Poor landings should
have been go-arounds.
HM
Try to hold the plane OFF the runway as long as possible; try to make the actual
landing a surprise.
Decelerate below 40, apply brakes.
Finding
Landing Attitude on the Ground
Problem
HM
On the ground for this part or in the air? I don’t know how we would lower the
tail on the ground....do you mean move the stabilator (or elevator) down?
GW
See if the instructor can lower the tail to the flare/landing attitude as you
move the yoke from neutral (level) into the full nose up position. Get some help
if necessary but by putting pressure (body weight) on the empennage just forward
of the vertical stabilizer you should be able to lower the nose. You want to get
a visual picture of the horizon line and the nose position, as it should appear
on landings.
Learn how to use the aircraft identification tag to check trim position during
preflight. Just forward of the stabilator on the left side of the empennage is
the aircraft identification plate. You center the nose of the stabilator on the
upper edge of that plate and note the position of the trim tab. For neutral the
tab should be centered by turning the trim wheel in the cockpit.
HM
I don’t know what this means so I will ASK about it.
GW
Move the yoke very slowly at first and faster and faster as aircraft slows and
begins to settle. Leave some power on for a while since it helps make the
touchdown softer.
HM
We cut power regularly...but I get the idea.
GW
You should be able to land both with and without power.
HM
All of the landing we make seem ok to me -- except for the bobbling we do in the
last 10 feet of altitude when I have the yoke. They all look and sound about the
same. Mine aren’t quite as CENTERED but the are in the
middle third AT WORST. We ‘screech’ tires just a
little but the instructor usually
does that when landing alone. Not loud or long, no bounces, one ALMOST
float I did but we did NOT go HIGH, and we settle smoothly
back ok.
The WORST landing that I made ALONE
(the only one I am sure that I did) was probably the BEST
feeling but the WORTH technique. My CFI
said, "You landed a little flat." It wasn't until the next day that I
realized I hadn’t asked what does that mean? (But I had guessed....)
I landed EXACTLY as I came level so from a passenger point
of view it would have seemed perfect, but it was dangerous because off just a
little and we would have stuck the nose gear. We came in, leveled and STOP
settling AT the running.
(Don’t get the idea that I EVER thought this was a good
landing, but it felt PERFECT from a NAIVE
point of view.)
I KNOW I will learn from my mistakes, I am trying to get
feedback on what those mistakes ARE and what is being done
to FIX the landing. Immediate feedback is best, timely
feedback is essential.
On
Moving the Yoke
Gene to Herb,
Work on this movement several times without the engine. With the instructor's
help outside the aircraft make note of where the yoke shaft is when the
stabilator is neutral (Learn how to use the aircraft identification tag to check
trim position during preflight) Then see if the instructor can lower the tail to
the flare/landing attitude as you move the yoke from neutral (level) into the
full nose up position. Move the yoke very slowly at first and faster and faster
as aircraft slows and begins to settle. Leave some power on for a while since it
helps make the touchdown softer.
What you are trying to do during the flare is to rotate the aircraft around its
lift axis so that the nose will just cover the far end of the runway. A good
landing is NOT a greaser. A good landing is not even soft. A good landing is
FIRM and occurs when the aircraft is ready to land despite of what you may do to
keep it flying
Your instructor (s) will show and tell you how they expect the pattern to be
flown and the airspeeds desired. For every leg you should be trimmed for
hands-off flying either level or descending at selected airspeed. Cherokees tend
to hold desired airspeeds as you add flaps. (Cessnas require more trimming.) Now
for the flare.
Practice making go-arounds when slow at altitude first I would suggest that you
fly as many left patterns as you do right and at a variety of nearby airports.
Consider making a series of low approaches at ever-lower altitudes and delay
your go-around until you can touch the far end of the runway without ballooning.
If you do this close enough to the ground you may touchdown without expecting
it. This is the landing you are looking for. Just pull off the rest of the power
and stay off the brakes until you slow.
HM
So: No anger, no unhappiness, maybe a TOUCH of frustration
at trying to OPTIMIZE MY performance and MY
interaction with the plane AND with the instructor (s) because...
I AM LEARNING TO FLY AN AIRPLANE.
GW
One of the more difficult aspects of learning to fly is overcoming all the
misconceptions you have acquired since childhood as to what constitutes a good
landing.
HM
Situation: ON FINAL. My current skill level is that I
probably cannot land well enough on my own and
certainly am not ready to solo just from a "landing" perspective. I am
at 13 hours and I have 'made'
about two, watched 3 and 'helped' on about 10 landings.
GW
This is one of the more difficult instructional problems. I know I keep my hand
close to the yoke but knowing just when to 'help' a student is very difficult
and every instructor will have a different threshold. You will learn far more
from your mistakes than you will learn from the things you do correctly. Talk it
over with the CFIs.
HM
I (student) have the controls with no indication that the CFI is going to take
them -- I will land. He still tells me pretty much WHEN to
do stuff like flaps...and gives instructions as we approach flare.
GW
Why don't you do the talking. Tell him everything you intend to do in
anticipation of doing it.
HM
During the glide break and flare (somewhere) he will stop giving clear
instructions, although he might keep mumbling something -- frequently it is what
I am already doing and so I DO MORE -- and then get a
"not so much".
This is similar to the way a plane reacts -- only the poor instructor has to do
it THROUGH a student, AND wait for
the PLANE to catch up -- the student is ADDING
back pressure GENTLY, starting more, HEARS
ADD MORE BACK PRESSURE just as he was about to get results, so he ADDS
EVEN MORE then hears, "NOT SO MUCH"
(panicky tone now). This sequence takes about 5 seconds but the ground IS
coming up and we ARE traveling 66 MPH
or so.
Ok, it's hard to SEE that someone is tightening or
loosening the backpressure (which is what makes learning to anticipate a plane
so hard in the beginning, it doesn't immediately do what you say and then if you
give it too much it does MORE than you intended.)
[One of your articles talked about doing everything so GENTLY
and so much AHEAD of the plane that to an observer it
seems like you are really doing nothing. Flying is easy.]
None of this is the REAL problem. The REAL
PROBLEM is that as we are about to land, I cannot tell WHO
is flying the plane. I was willing to let is go as just "deal with it"
until you don't need help.
BUT
today, my instructor said just before touchdown, "You're overpowering me." Remember, I(Student) HAD the airplane. I relax but kept my hands on the yoke and let him fly it about the last 6 inches, we touch down it was a nice enough landing, and as we decelerated I was NOT 'flying' the plane although I was still "in the game" with attention to the rollout and hands in position, when he said, YOU still have the airplane. No problem, centerline, wait for speed, break, get off.Another Related Subject:
ALL of the books, ALL of the
instructors talk about NOT getting "behind the
plane", "behind the situation", or about "staying
ahead". But no of them (you may have this somewhere on your web site but I
have only scratch the surface there) seems to emphasize, verbalize, or maybe
even REALIZE that ANTICIPATING the
plane is DIFFERENT from anticipating most anything else.
GW
Staying ahead of the aircraft means that you know (should know) what to expect
next from the aircraft and yourself. PLUS the next
expectation. Consider yourself behind if you are not two steps ahead. Now, you
can't do this the first time or perhaps even the fourth time you are exposed but
you need to walk and talk through all the procedures you use in the pattern on
the ground until you can stay two steps ahead.
GW
By the way, it is just possible that your seat position in height and distance
from the rudder/brake are not optimal. Check on it. It is just possible that you
are seeing too much over the nose because of your height. One way to check is
having the instructor lower the tail into the full stall flare position and see
what it looks like 1000' ahead. Compare your visual reference to his by lowering
the tail with him in the cockpit.
HM
[It’s like the difference between "velocity" and
"acceleration". Velocity can kill you but with acceleration you may
not even see it coming. <grin>]
Example: You want to catch a speed (MCA) or an altitude
(level off), so you PLAN ahead, you start early
("see, Ma, I’m anticipating") but then when you reach that point,
that altitude, that speed, or that state everything is RIGHT
WHERE it should be with ONE HIDDEN difference: The
rate of change. Sure you are on airspeed, sure you are on altitude, sure you
have whatever you were seeking, but there is SOMETHING DIFFERENT
about the state you don’t KNOW is different (usually TOTAL
energy) so even though everything is perfect it stays that way for about 3
seconds.
Then the energy decays further and MCA is either too slow
or you lose altitude. Or you level off with TOO MUCH ENERGY
and you find that while you are trying to GET THE NOSE
down and build up airspeed things are changing (ENERGY
again) and you start mucking with the throttle (listening helps a LOT
here) and you slide UP further than you wanted. Sure you
could have started leveling off sooner (that’s anticipation, right?) but you
would have ended up reaching you altitude tentatively and after your sort of
leveling off 50’ low, then sort of ‘oozing’ up once the airspeed builds
up. Maybe that’s even the right way? But the point is that it isn’t just
about thinking ahead of what’s HAPPENING now, or even
about what is going to HAPPEN next, but rather about
thinking ahead of the ENERGY (and aerodynamic) STATE
CHANGES and even acceleration of those change that will occur next.
Does that make any sense? It sounded so good, I am going to say it again:
GW
What you have stated is o.k. But in the real world of flying, just how do you
level off at cruise speed, how much altitude lead do you allow, do you retrim
immediately or after the aircraft has accelerated to cruise. How many times do
you re-trim and how long does it take? Work to make what you do more efficient
and then anticipation will fall into place.
Herb's
Opinion on His Landings
Here is what *I* (personal opinion) think you might consider:
1) Pain is a way of telling us to PAY ATTENTION or to TAKE
a DIFFERENT ACTION.
2) Unnecessary pain is unnecessary -- if you are paying attention
3) Don't beat yourself up (like they said) but EVERY TIME YOU
START or even CONSIDER beating yourself up, SEEK
OUT what it is you should be PAYING ATTENTION TO,
or what ACTION you should take to FIX it.
4) If you say you stink that is both UNFAIR and a way of HIDING
the TRUTH, try this instead...use it LIKE A
CHECKLIST
I stink. No, wait -- How SPECIFICALLY do I stink. That was
a LOUSY landing (or whatever) Lousy in what way?
I did X (ballooned, came in too fast, blah blah)
How much to fast, slow, high?
When did it happen?
When did it FIRST go wrong? Were you correcting another
mistake
that happened earlier?
Did you KNOW what to do and just not do it? (Forgot,
misunderstood,
slow to react, overreacted?)
...OR do you need to ASK or FIND
someone who can help you UNDERSTAND how it happened and HOW
TO FIX IT.
Until today I did NOT KNOW how to land. A wonderful young
lady CFI helped me make 9 landings and I "got" it. Like everyone says,
"getting it" does not mean that I am FINISHED
learning landings. What I "got" was the BASIC idea so that I can begin
JUDGING my own landings.
As I learn to land better I will be continually UPGRADING
that judgement just as I continue to upgrade and improve my physical and motor
skills and procedural skills. I now have a basis for DECIDING HOW
I messed up.
Sure I still need an instructor. Lots of people have solo'd by my (NOW)
16 hours and I am a very competitive person -- not so competitive with OTHERS
but extremely competitive with MYSELF. Soloing is UNIMPORTANT
AS LONG AS I am learning. It really doesn't matter
how soon the instructor leaves that right seat as long as they are keeping me SAFE
and TEACHING me stuff. (Ok, I am paying $28/hour so they
had BETTER be doing BOTH.
<grin>).
Now, if you didn't KNOW what was happening then I think it
was an INSTRUCTOR that may have stunk, but...If you KNEW
what stopped you (or caused) you to do that? How would you do it differently --
this is VERY IMPORTANT you must now make a VISUAL,
AUDITORY, and KINESTETIC (feelings) full color,
stereo, concrete movie in which you are the STAR ACTOR.
Imagine you are playing the role of a PERFECT PILOT or
even the STUNT MAN who REALLY flies
the plane -- pick someone you know who really is the best if you have someone in
mind, otherwise pick YOUR IDEAL pilot. Now take the ACTUAL
5 minutes it takes to go through downwind, turn base, check traffic, turn final,
and LAND it perfectly. Add in all the DETAILS
I left out in the previous sentence.
Do not try to make it faster than real (it is cheaper than renting a plane), but
you can make it SLOWER if you MUST
to get everything done perfectly. If you make a MENTAL
mistake, run the mental movie backwards (can't do this in a plane) until you are
doing it perfectly again and then run forwards doing everything perfectly.
When you have it perfect. Do it one more time if you had to make a lot of
rewinds. Mentally imagine using the rewind button on your VCR
and even the PAUSE if you must. Then run it through
smoothly. Then SPEED it up and do it as faster than normal
(not high speed just as fast as you can handle it.)
BTW, I had so much fun just landing that plane and knowing that I COULD
land it whether the instructor was there or not -- sure I might have to go
around until I found one I liked, but I COULD
Then I was hanging around the office planning my schedule for flying after this
week (5 days forced layoff due to work) when I noticed as I was about to leave
that she had a cancellation: Result: we went back and did it again.
This was perfect -- had just enough time to rest, relax, and integrate the first
9 landings in my first pattern work -- went pack and did another 0.7 hours and 6
more landings and a go around that I caused by bad setup. Sure, I could have
gotten it in but it would have been ugly and the might have required a FULL
STOP due to runway. I knew what I did and I CAN FIX THAT.
After today, I have 16.4 hours and 29 landings (more than TWICE
as many landings <BIG GRIN>) Some of the best flyers
in the world are the exhibition teams:Blue Angels, Thunderbirds, etc. The Blue
Angels have a couple of POLICIES that are TRULY
amazing and wonderful for LEARNING, IMPROVING
and doing it SAFELY.
If you ever see the Blue Angels documentary on "Discovery" channel or
some such, TAPE IT, WATCH IT. The
flying is cool but THE METHOD is EVEN
COOLER IF you are LEARNING to FLY
BETTER -- these wonderful pilots -- as good as they
already are -- they ARE LEARNING to FLY
an AIRPLANE BETTER EVERY DAY. Wouldn't
we like to do the same thing (at our own level of skill)?
Here is the basics:
Before EVERY flight they pre-brief the flight with the
"Boss" calling out timing points in REAL TIME
and everyone making mental movies of what they will SEE, HEAR,
and FEEL (maybe even smell), throughout the flight -- how they will time it,
when they will know a cue, how they will do it.
Then they fly - this is the part that LOOKS perfect to
almost anyone observing.
Then they REVIEW the flight: Around the table EVERYONE
tattles on EVERYONE, including -- especially --
themselves. No finger pointing just, "Dutch was low slightly when we did
X" or "I was a touch late doing Y when lead did Z". Everyone OWNS
up to everything that was LESS than PERFECT
without feeling bad about it. They admit their own mistakes; they point out the
mistakes of their friends and even of "The Boss".
As each deficiency is noted, the person who (understands it and agrees with the
criticism) says (AND MEANS it): "I CAN
FIX THAT." At the end of each persons review the TRADITION
is to say, ". And I am GLAD TO BE HERE". They
all claim that they are "just ordinary Navy fleet pilots and that any fleet
pilot could have their job" and so they are well and truly "glad to be
here". They also MEAN it when they TAKE
RESPONSIBILITY and say, "I CAN FIX THAT."
Criticize yourself -- or MYSELF -- THAT WAY and we will
all LEARN TO FLY an AIRPLAINE
Happy Skies to you.
HM..
Flew the last two days -- all pattern work on the landings. Figured out that I
was landing TOO LOW-- there was no (practical) way to hold
off or flair from that (lack of) altitude because any sink would put the mains
down. This turned out to be the MAIN problem -- the rest was just cleaning up --
and continuing to perfect -- ALL the little things to make
it easier.
Yesterday, did 20 in 2 hours and it was clear that I was close enough and had
solved the biggest problems. Had some wind but that wasn't a big factor.
[Different instructor -- #4 -- he was good, patient and helped] My main
instructor is heavily booked. My 2nd CFI is quitting the business -- guess I was
just too much <grin>.
Seriously, he decided that trying to make a living with a family as a CFI wasn't
realistic for him. So he is only going to work with his "official"
students until he can close out or transfer their training. The young lady is
"back in school" so she's not available much either.
[Different instructor -- #5 -- he TOO was good, patient and was GOOD about
explaining anything he did and WHY] Today, I would have take all 12 as
'keepers', even though they were improving generally. They key is that I had it
under control and was performing the landing nose up as expected.
Again, thank you for all your help. I am reading your site and know that I will
have some specific questions again soon.
One piece of advice -- from your web site -- has been particularly effective
during this 'landing intensive period'. ACCEPT the
COST and once you decide to fly, live with the fact that it will cost
a certain amount of money to learn to fly an AIRPLANE.
I am definitely not poor but I am also not 'rich'. I have enough money for those
things I really want but I notice it each time the next $1000 "on
account" is needed by the school. Each landing costs me about $10-12 to
practice -- and that is at the 'discount' "touch and go" price.
<grin>
Herb Martin,
GW
I am into rental real estate. Every time a tenant leaves I know that I will have
considerable expense in renovating the unit for the next renter. I make
improvements and raise rents accordingly. Rents that 40 years ago cost $104 can
now bring $900. I look on a vacancy as an opportunity not as an expense.
You should consider the cost of learning to fly in the same way. Your return may
not be as money. My flying has rewarded me with far more than money and yours
can too. The fact that my flying 'business' loses money two years out of every
three keeps the IRS and my wife out of my face. I have made a world wide spread
of friends through the internet land a common interest in flying. I can now look
at the cost of flying as an opportunity not an expense.
I do feel sorry for those who must deal with flying in any other way.
Gene
Advice to
a Student on Landing
The process of making a landing is a series of anticipations. The better you can
establish as many 'constants' as possible the fewer things you need to watch,
adjust, or find unexpected and unanticipated. The first and easiest constant
to set is your seat position, then in no particular sequence comes power
settings, trim settings, configuration changes, visual perspectives, and more.
Suggest you sit in the aircraft and study the way the yoke moves forward and
back. The geometry of the hand and arm tend to twist and pull down as you pull
back. This will bind the shaft of the yoke in its guides. Don't use all the
finger grips. Work with only one or two fingers at most during the roundout and
flare. . You should note that the last 9 inches of yoke movement LIFTS
the yoke about three inches. You must LIFT to keep
the yoke from binding and turning. The speed of movement is not constant. Speed
of yoke movement is almost logarithmic and the faster it moves the greater the UP
component should be. The manner in which you move the yoke must be
practiced. The effect of the yoke movement is not intuitive. Effect depends upon
speed, ground proximity, air density, weight and balance.
One of the more difficult aspects of learning to fly is overcoming all the
misconceptions you have acquired since childhood as to what constitutes a good
landing.
This is one of the more difficult instructional problems. I know I keep my hand
close to the yoke but knowing just when to 'help' a student is very difficult
and every instructor will have a different threshold. You will learn far more
from your mistakes than you will learn from the things you do correctly. Talk it
over with the CFIs.
You should know a bit about the structure of the control system in a Piper. The
stabilator has a long arm extending well into the empennage and at the very end
is a heavy counterweight. Strength is not a requirement for making the flare.
Just lift with one finger under the horn of one side of the yoke.
All of your foregoing comments about student/instructor communication are
inherent in the instructor-student relationship. Have you considered using a
tape recorder such as I suggest on my site. I have over 10,000 hours of taped
flight instruction floating around out there. Just perhaps having your
instructor listen to a tape with you might help you both realize what is
happening.
Staying ahead of the aircraft means that you know (should know) what to expect
next from the aircraft and yourself. PLUS the next
expectation. Consider yourself behind if you are not two steps ahead. Now, you
can't do this the first time or perhaps even the fourth time you are exposed but
you need to walk and talk through all the procedures you use in the pattern on
the ground until you can stay two steps ahead.
By the way, it is just possible that your seat position in height and
distance from the rudder/brake are not optimal. Check on it. It is just
possible that you are seeing too much over the nose because of your height. One
way to check is having the instructor lower the tail into the full stall flare
position and see what it looks like 1000' ahead. Compare your visual reference
to his by lowering the tail with him in the cockpit.
What you have stated is o.k. But in the real world of flying, just how do you
level off at cruise speed, how much altitude lead do you allow, do you retrim
immediately or after the aircraft has accelerated to cruise. How many times do
you re-trim and how long does it take? Work to make what you do more efficient
and then anticipation will fall into place.
Herb,
Well, I pretty much 'stunk' (as the guy said the other day on the news list)
today and yesterday
while landing.
Gene,
Made a good (excellent) landing Thursday. 70 degree crosswind at about 17 knots.
Chirped my right wheel just before the nose and left touched. In a C-172 or
PA-28 a backseat passenger sure helps in making the flare. Friday night got my
night currency back. Night gets harder as you age.
Herb,
Round out is fine, center and stabilization is good. I either flare to little or
balloon up MOST of the time. Most of the landings are firm
but gentle but the nose is NOT up.
Gene,
When you find that there is variation in your flare that relates to a balloon or
insufficient raising of the nose the cause is related to variations in airspeed.
The stabilized approach has an additional requirement that the speed over the
ground be very near the same each time and at the same altitude. When your
approaches have a certain level of consistency, you can begin to round out and
hold the aircraft in ground effect until you ' or 'sense/feel' the aircraft
begin to sink towards the ground. You are NOT looking inside the cockpit. You
have your eyes looking wide vision to both sides of the nose at the horizon.
The instant the horizon begins to rise it means the aircraft is sinking.
You have your elbow braced against the cockpit side and you use your fore arm
and fingers to raise the yoke up and back so that the plane is made to 'rock'
rather than change altitude. You are not intent on landing the aircraft. You are
intent on getting the aircraft into a landing attitude with the nose touching
the far end of the runway. If you move too much or too soon you will balloon. Do
NOT go forward. STOP and wait for
the horizon to begin to rise again before starting your lifting of the yoke
again. If the plane falls too fast, go-around. You must make some
mistakes to learn how and when to do what.
Herb,
I am forced to CONSIDER that this is mostly due to lack of
verbal ability on the part of the two male instructors (and my own lack of
competence to do it own my own yet.) They will be saying MORE
PRESSURE INTO the balloon.
Gene,
Start talking to yourself as you feel appropriate so that you can anticipate for
yourself what you should be doing. Hopefully, your talking will shut them off.
Herb,
I know how to land; I have done it; and yet they are yammering at the wrong
tempo -- I do what I am told but I believe their inputs are delayed too much.
Today's instructor is NOTICEABLY better than my
"primary".
Gene,
Every student learns to land somewhat differently based upon pre-conceptions as
to what is involved. It is the unlearning of preconceptions that is the most
frustrating part of flying. The good landing you visualized when playing with
models MAY still be into your subconscious. Make a point
of watching ducks land. Their head is up and feet sticking out in front. Pretend
you are a duck.
Herb,
Please excuse me but I am disappointed in them -- and in myself for not doing it
right IN SPITE of mediocre instruction.
Gene,
Your instructors are teaching the way they were taught. They are trying to teach
you that and the way they succeeded with previous students. You are different
and they will learn from you things to try with students down the line. Even
the best of teachers have difficulty with about 5% of their students.
Jumping between instructors may not be the way to go in the beginning??
Herb,
This is why I am so excited about flying with you and I do NOT
want you to get the idea that this is my usual attitude. Heather gave me just as
much if not MORE HELP, and did it so that it CONTRIBUTED
to my performance. She doesn't have enough slots open to just switch and today's
instructor is fine except at flare.
Gene,
When we fly together, it is my intention to let me see what you know and what I
perceive as your not knowing.
War Story:
Had a student who was getting ready for solo but having difficulty getting
everything together. At one point just about everything went wrong and on
touchdown I said we would do a taxi-back. I had already completed the paper work
except for date and signature. When we got back to the runway, I told him he was
ready for solo. He was surprised but I told him that he had demonstrated his
ability to replace all the instinctive reactions with trained reactions. Neither
instructors nor students should be looking for perfection. The goal is judgment
and safety.
Herb,
[Had a close call in pattern traffic today too. Someone cut across mid-field
right over our downwind. I was looking but didn't see them until they were
virtually atop us -- not a near miss, but any closer would have been REAL
SCARY. It is a good thing that they were NOT
exactly at pattern altitude as my primary instructor taught me when over flying
-- that is NOT what the books say to do.]
Gene,
No answer for this problem. However, some mitigation is possible by flying when
the winds and weather are relatively unpleasant. The statistics of midairs are
worth study. I have written quite a bit about risk factors as well. Acceptance
of risk is a part of flying. Reduction of risk is a part of training.
Elimination of risk gives the FAA guaranteed employment and unlimited FAR
production .
More Notes to Herb
Nice to have runway with cardinal headings. You should have noted by now that
'The Sum of the Digits' are equal in the pattern regardless of the runway number
180=9, 090 = 9, 270 =9 360 =9 or on the other runway 110 = 2, 200 =2, 290 =
11=2, and 020 =2. The 45s work the same as well but not as useful.
When you enter a no-wind 45 entry for a left pattern your runway heading will be on the left-rear of your heading indicator. When entering on a right 45 the runway heading will be on your right rear. Helps making 45 entries to strange fields. Use E6-B or HI to see this.
If most aircraft come in using the same call-up points and even altitudes, try this. Report as being, "One north (reference point) at two-thousand three-hundred (2,300) planning left 45, 18 Georgetown". This gives you a safety margin over those who always fly 2000, 2500 etc. In a low wing aircraft, it is somewhat safer to come into the pattern a bit low 1600 AGL on the 45 because your visibility it better up than down for traffic. Be at pattern altitude on downwind.
Always trim for level, hands-off flight on downwind. Note the amount of trim required so that you can get close to proper setting in one move and then make small changes. Counting buttons on trim wheel is one way.
Have you noticed that when reducing to 1500 that as the plane slows you must bump it up a bit? Consider reducing power to between 16/1700 so that deceleration of plane will cause rpm drop to 1500. Anticipation! Some airports (mine) prefer that no altitude be lost until turning base for noise abatement. What you do to the trim on power reduction will be different then.
Too bad instructor did not explain about Vref at this point or later on the ground. The POH speeds are all at gross weights. When you are below gross weight, as you usually are without a third person in the plane, you should figure your speeds for landings based on the percentage your present landing weight is less than gross weight and reduce you approach speeds accordingly. Very simple to do but have instructor work it out with you for his benefit.
For some reason the recent FAA preference recommends against the use of the 'key' position. Don't tell examiner what/why you do as most pilots do as well. (About 1995)
The interesting difference between Piper/Cessna is that addition of flaps in Pipers require very little trim change, where as Cessna pilots are always trimming. Recent Cessna Training Centers are using a system that allows patterns to be flow much as do Pipers. Works either way. In my opinion any flight training that minimizes the use of trim and its associated control pressures is opening the door for a accident caused by distraction.
Very important that you become proficient with making corrections in your glide path. When low, the worst thing to do is adding a bit of power. At altitude, put the plane into a landing approach configuration and then do nothing but add 200 rpm. Tell me what happens as opposed to what you 'think' happens. You will slow your airspeed.
There is only ONE safe option when correcting for being low. When high you have three options. They are? Proper sequence? Why?
You never mention carburetor heat? Why? When? What do you do if engine dies
at 400' on final?
See what instructor comes up with. Try at altitude and then at airport.
(Appropriate altitude) Variable because of headwind velocity. In any wind over 15 knots don't be concerned about being high on approach.
(Make sure the aiming point is NOT rising or falling in the windscreen.) I would be more concerned as to having a stabilized approach at constant airspeed. Airspeed trimmed for hands-off flight will maintain a constant sight picture.
Your BREAK is more commonly called the round out where to attempt to level the aircraft off with the wheels about hip high. Airspeed here is critical, this is the only way you can develop the site picture and yoke movement pattern than will allow a smooth roundout without a balloon. Because of the long low wing you will balloon if too fast. Go-around as your first and best option. The major variable that makes consistency difficult is changes in air temperature and density. What you wait for during the roundout is that as the plane slows in level flight you will feel an elevator-like sink as a signal to begin raising the nose. The worst thing you can do is trying to keep the runway in sight. A landing is an act of faith helped by what you see to each side of the nose. I presume you played some football. The linemen have learned to 'split' their peripheral vision between the ball and the guy in front.
The pilot must split his vision to each side of the aircraft nose. There is a horizon line that measures the rise and fall of the aircraft. If the horizon line falls it means that the aircraft is rising. When the line rises the aircraft is falling. It is acceptable to stop moving the yoke back-up to stop or slow. It is a major NO to move the yoke forward however slightly. Go-around! The worst thing that could happen to you is to
What you should be trying to do in the flare is to keep that (horizon) line still, neither rising nor falling as you 'tilt' the nose up for touchdown on the main landing gear. The gear designed to absorb considerable impact. Important that you do not allow the shock of landing to move the yoke forward so the nosewheel hits hard as well.
Perfect landings are lucky. Good landings are occasional. Poor landings should have been go-arounds.
A
Plea for Help
Navigation, weather and charts are the only three areas of aviation you
should not try to self-study.
Reading a sectional should begin with learning to read the longitude and
latitude hatch marks that
divide the chart into rectangles. The charts are expendable so mark them up with
colored pens. Have someone show you how to find the longitude/latitude location
of an airport and then you do several until you can do it fairly quick. Use a
long ruler to make sure your lines are straight. If you have an AF/D directory
the longitude and latitude of every airport will be there.
Only some of them will be on your sectional. Important that you know the
nautical mile distance can
only be measured on the vertical lines. Look at a globe in a library so you
can verify how the horizontal distances have the same number of marks over
smaller space as you leave the equator.
Once you have learned how to find where you are on a chart, it is time to learn the things shown on the chart. Make a black rectangle using a quarter section of a full degree distance in Long/lat. Circle all the little symbols in the rectangle and use the legend panel on the side of the chart to identify every item. Get help for those you can't seem to identify. Do this until you can randomly pick an area and be able to identify most of the symbols. Some of the instructional videos explain charts very well.
Certain symbols have a variety of forms, such as VORs, airports, towers, and airspace. You will never truly understand airspace until you get the opportunity to fly into the multiple situations created by both the colored lines and the weather influence on them. Some of the lines are only effective when the weather gets bad. It is important to know the differences between the related symbols.
I would suggest you go to a library and get a basic geography book that explains and names the different shapes of land and water. Additionally, you want to note how the shading and colors are used to give altitude and shape to the parts of the charts. I have written about some of this in the History section of my web site. http://www.whittsflying.com
Last, you must understand that there is a wide variation in student ability to understand spatial relationships. You should begin at your home airport and have someone point to all the cities that are within driving distance. You want to learn your home area first and how it is depicted on the chart but learn to 'read' the ground first.
Consider drawing a two-mile circle around your airport on a chart and on a regular road map. Note the differences and similarities. Have someone fly you over some of the places you have identified. You will find that flying low or high makes a great difference in how you see and find things. Finding strange airports will never be any easier. Draw a five mile and ten mile circle and learn as much as you can about the names of schools, hospitals, golf courses, and places pilots are familiar with.
Lastly, get two old sectionals and paste them together if it is necessary to get a pizza sized circle to cut out with your home field in the center. This is only needed if your home field is near one edge of the sectional. Paste the chart on to a piece of light cardboard Using the circle mark off every 30 degrees magnetic around the outer edge of the pizza. Draw colored circles from the center at 2, 5, and 10-mile radii. Hilite all the points that could be used in radio communications to show where you are relative to the airport as well as the points that others might use to tell where they are relative to your position. These points along with altitude will make flying safer for all. I have used the backside of the pizza to paste the radio call-ups, position reports, and advisories I might use when arriving from any direction. I paste the radio calls so that just by flipping the pizza over I can see what my calls should be according to the direction of arrival or departure.
It is vital for your mental and emotional well being that you know where
you are when flying. Being able to tell where you are is equally
important. With the pizza you can have your own departure and arrival
simulator to practice for each flight. By flying frequently but going in and out
from varied directions you will soon be able to discard the pizza and fill your
plate with healthy food.
More if you wish...
Gene Whitt
Opinion (Excerpt)
One thing about the VSI: really sharp instrument pilots will use the VSI for
primary pitch on the ILS instead of the AI. As long as the corrections are
immediate and smooth, the VSI makes it much easier to hold a glide slope at a
constant rate of descent. In this case, power controls airspeed, and the VSI is
used as primary pitch cross-referenced with the AI and altimeter. Although
using power to control airspeed is opposite of what you learn as a VFR pilot, it
makes for a much easier ILS. You literally fly the slope with the VSI, making
small corrections to maintain or regain the slope as needed.
Dudley Henriques
Night
Flare
Problem
Gordon Clark wrote:
Anyone got any great ideas on how to flare at night. I'm working on my Canadian
night endorsement and while the landings haven't been awful, I generally seem to
be thumping on from a little high. Pattern work is fine, control is no problem
but last time up two nights ago - in cross wind, though - I had some pretty
thumping landings with 30 degrees of flaps on. Hard to judge height over the
deck, no?
Solutions
Hard to judge height over the deck, yes! The problem is simple. You tend
to land on the plane of the runway lights. They are usually up on stalks!
How to avoid the problem? If you have lots of runway, carry a bit of power
over the threshold. Set the power to give you about a hundred feet a minute
rate of descent in your nose high touchdown attitude at about best angle
airspeed.
Slow to that speed with that power established on short final and round out.
Then, if you have plenty of runway, just let it settle to the runway. That slow
descent will gentle you on. It is sort of like a glassy water seaplane landing. You
can't judge your altitude over glassy water either.
I remember, about thirty years ago, United came out with a directive asking
their pilots to stop flaring to land. Establish the attitude on short final and
let it fly onto the runway by itself. Makes a more consistent landing. Don't use
it for short field work though! :-)
Highflyer
The secret to making good night landings is to learn how to effectively you use
your peripheral vision to allow you to gauge your height above the runway. It's
something that you must practice with a good instructor until you get the hang
of it. When you do, you will be able to turn your landing light and cockpit
lights off and land with only runway lights as a reference. This skill comes in
handy if you lose an alternator and battery and have to land with a darkened
cockpit. I've had the opportunity to use it twice for real.
PD
As soon as you start getting close to the runway, look down to the lights at the
opposite end. Just like daytime, looking down to the end of the runway gives
you a better sense of height above the runway, with less of the illusion of
being close and fast that you get when you look too near the nose.
Colin Rasmussen
Mike Szewczyk wrote:
I had a problem with that. Then we turned on the taxi light which shown down
onto the runway when I got close. This gave me a better visual idea of how high
I was.
Using Rudder
Problem
When making turns, should the aileron and rudder inputs be done simultaneously?
If so, does this hold true for all turns, regardless how severe?
Advice:
Having been an aerobatic pilot and aerobatic instructor, I use a slightly
different approach to rudder use in turn entry and exit. I've found it so
effective in teaching acro that I gave up teaching student pilots to use the
ball years ago. Rudder and aileron are used together in all turn entries and
exits. The trick is finding the exact amount of each required to produce the
exact rate of turn for the angle of bank you have chosen
The best way to do that is WATCH THE NOSE, not the ball! Either
the ball or the nose will tell you instantly if the inputs are correct. The
difference is that by watching the nose, your head is outside the cockpit where
it should be instead of staring at the ball. Make no mistake; the nose will
tell you instantly whether the inputs are right. The nose is nothing but a
huge ball, just sitting there in your field of vision waiting to be used to tell
you about the quality of your rudder use! Now this next part is important, so
listen up!! :-)
Even though you can consider a turn entry and exit to be a blending of correct
aileron for rudder as well as the opposite way around, make it simple for
yourself and concentrate only on the rudder end of this delicate equation. In
other words, accept whatever aileron you are using and attempt to marry the
right amount of inside rudder to that aileron. Now you're only dealing with the
inside rudder, and the amount of rudder you are looking for will vary as a
function of whatever aileron you have chosen to apply.....heavy aileron....more
rudder needed......light aileron.....lighter rudder.
What you're looking for is an EXACT PIN of the nose as the
turn is entered and exited. Too much inside rudder will slew the nose inside the
turn and too little will slew the nose to the outside of the turn. ANY
lateral movement of the nose except staying EXACTLY
pinned is unacceptable. If the nose tells you you're skidding, correct it by
using less inside rudder. If the nose tells you you're slipping, use a bit more
inside rudder. If you notice here, we're dealing only with INSIDE
RUDDER!! Releasing too much inside rudder will do the same thing in
correcting a skidding entry to a turn as applying outside rudder to correct it.
The difference is that it's a smoother correction and keeps you dealing with
only the inside part of the problem. If you're using too much inside rudder or
not enough, you correct accordingly. The answer to correct rudder use in turn
entries and exits is simple; PIN THE NOSE!! You practice
this a few times and get it right, and you probably won't ever look at the ball
again! :-))))
With about an hour's practice trying to pin the nose visually while varying
amounts of aileron and inside rudder to enter and exit from turns, you should be
able to do this automatically. One thing!!! Don't forget to apply back
pressure for the turn, and bleed that back pressure off during the exit!
:-))))Good luck,
Dudley Henriques
Flare
Problem
Herb Martin wrote:
I THINK you MEAN that you START
the roundout and I meant the LEVEL part at the END
of the roundout as you begin to hold off. Surely you don't level out (correct
me) at 25' above the surface. The original issue was AFTER
the round out, when flaring or holding the plane off the runway in the landing
attitude.
Both the original poster and myself report no problem with the round out but
trouble with the HOLD OFF (flare
to landing attitude.) My thinking was that I am TOO CLOSE
at THAT leveled point. I DO have
excellent hand and eye coordination, and although it is good enough to get me LEVEL
VERY NEAR the surface it is (perhaps) NOT
PERFECT enough to get the nose up while letting the MAINS down slowly.
This DOES make sense -- although it might be completely worthless in practice.
Let's exaggerate it: If you were 1" above the surface, level and waiting
for speed to bleed off, the FIRST indication of "sink" would be at the
MOMENT the gear touch. (What you never want is the lifting sensation
indicative of ballooning.).
If you were 50' feet above the surface and level, waiting for the speed to bleed
off would PROBABLY leave you stalled with a long way down. If you were 3'
[replace with correct value] off the ground and level, as the plane sank the 1st
foot you could hold the nose up, as the plane sank the 2nd foot, you could
increase the pitch, as the plane touched down on the MAINS you would have the
nose well up. (The secret is lifting the yoke rather than pulling and
twisting back.)
If I am wrong, I hope someone will tell me how so and where to look for the real
problem. I can fix what I can understand or I will have to wait to get lucky and
then duplicate it until I have that "mysterious feel" for it.
Instructor Opinion
Once you level out, just come back fast enough to keep it from settling! I look
at the world out of the corners of my eyes. (Not over the nose as much as at
the hoirizon on each side of the nose.) If the world is rising in my
view, I ease back just a little faster, if the world is going down, I just hold
it where it is until I get back to where I was.
I don't worry about settling that few feet to the runway. You cannot
prevent it from happening if you do not add power. What I am doing is converting
all of my extra speed into the power I require for "level"
flight just above the runway. The speed will decrease quite quickly until the
airplane cannot fly any more. Then you land! :-) Highflyer
One of the most confusing terms in all of aviation is the term
"flare". It's so confusing, that I literally took it out of the
vocabulary I used in teaching people to land airplanes. The word doesn't even
come close to describing what you actually have to do to accomplish the
"flare". It's just a word,. nothing else. As a student, you reach the
landing end of the runway and suddenly the picture gets a bit more complicated
than the simple word "flare" implies.
Now that being said, stop and think for a moment. What is it you actually want
to do with the airplane? It's simple; you want to put the darn thing on the
runway in one piece. Well, before you do that, you have to accomplish a few
things, or the "one piece" part becomes more important than you want
it to be. The first thing you want to accomplish, and this first thing sets the
table for everything that will follow, is to imagine a big vertical square,
right at the landing end of the runway. What you have to do is arrive at that
square, and fly through it, in a landing configuration. That means having the
airplane ready to land. In a simple trainer that means flaps where they should
be, altitude where it should be to pass through the square, and airspeed on
target. Passing through this imaginary square with everything in place as it
should be is your first priority.
Assuming you reach this point ok with everything set as it should be, you can
now land the plane. Assuming no wind,
what exactly do you have to do to land the plane? You're at approach speed. Do
you want to land at that speed.....NO! You're little problem now is to put that airplane in a "LANDING
ATTITUDE" and HOLD IT THERE!!!
Now, what the hell is a landing attitude? It's accomplished when the airplane is
about a foot off the runway in a position that would allow it to touch that
runway IF YOU LET IT!
This is the key here. Your job is to HOLD IT THERE until
the speed drops off to stall. As the speed drops off, the airplane wants to
land. NOT YET!!! You counter this with increasing the
backpressure to stop the landing. More airspeed is lost. The airplane settles
toward the runway. You counter again. It's a contest between you and the
airplane. It wants to land. You won't let it land. The perfect situation now
occurs when the airplane touches the runway and you run out of back (and UP)
elevator at the exact same instant.
The hard part, if indeed there is a hard part in all this, is acquiring the
visual cues that tell you when it's time to hold the airplane in the landing
attitude. There are several things that will help you with this. One thing
you can do is take a long look over the nose just before you apply power for
takeoff. That's the look you will see at the exact point the airplane
touches down, so you know the landing attitude height will be above that look.
One thing I did with students when applicable was to have them perform an
exercise where they were required to fly the approach, then, keeping the
airplane in the landing configuration, fly it up the runway in the landing
attitude without letting it actually touch down. You may or may not have the
runway to do this. Ask your instructor.
The reason you are having trouble is simply because you haven't acquired the
visual cues yet you need to keep the airplane in a landing attitude while
letting the speed drop off before you touch down. Don't stare directly over the
nose. Look up the runway to the far end and "scan" the runway with
your
eyes as you hold the airplane off. Do this a few times and it will all fit into
place.
Remember, it's simple really.
1. Get to the square with everything in order.
2. Put it in a "landing attitude" and hold it there!
3. The job is NOT landing the airplane while the speed dissipates.
3. When you can't hold it any longer. Just be in THAT LANDING
ATTITUDE!!!!
Dudley Henriques
Problem
Dudley posed the question as to why the lift component of an aircraft in a climb
was slightly less than the drag component.
"David McKenzie, answered:...
Because thrust now has a vertical component!
Dudley's analysis:
Lift in a steady state climb is one of the most misunderstood issues in all of
aerodynamics. When discussing the four forces in any scenario but steady state
level flight, a COMPLETE examination of the force dynamics is necessary for an
accurate answer. The trig will reveal much more than a simple "lift equals
weight" and "thrust equals drag" answer
Aside from the oft quoted misnomer that climbs are the result of "excess
lift", the omission of the thrust component from the steady state climb
answer is a close second place mistake.
Dudley Henriques
The Ball
The Problem
With all the recent postings about the Slip/Skid Ball, I'm surprised no one
has yet asked the following interesting question: Is "coordinated
flight" always the same as "ball centered" flight?
The answer is NO! The ball is an instrument, and as such, it suffers from
the same three-letter word that all instruments suffer from --LAG.
As an instrument, the ball is least accurate while you are in the process
of making dynamic changes/ control inputs. The ball is most accurate
"after the fact" -- when you are near a steady flight condition. The
ball then allows you to fine tune your yaw control.
A good demonstration of the inherent lag in the ball is a simple coordination
exercise (called a Dutch Roll by aerobatic pilots--has nothing to do with the
Dutch Roll instability of swept wing aircraft, though):
Looking outside over the nose, and while keeping the nose on a point, smoothly
apply aileron and rudder at the same time, in the same direction, and roll to
say thirty degrees of bank. Then immediately switch your control inputs to the
right--right aileron and right rudder--to an equal bank angle to the right. Then
switch again.
Continue rocking the wings left and right in this coordinated manner (just like
you should be doing any time you're banking, be it into or out of turns).
The biggest problems in this exercise--pilots usually don't apply enough aileron
and often too much rudder. Also, the rudder input must exactly coincide with the
aileron input. Not before, not after, but timed with the aileron.
Most non-aerobatic instructors who try to teach this exercise often do so as a
cross-controlled maneuver, to what benefit I don't know. This should be a
coordinated maneuver (as evidenced by the feel in the seat
of the pants and the nose of the airplane staying on a point on the horizon).
If you try doing this exercise by looking at the ball and trying to keep it
centered, the nose of the airplane will slew all over the sky and everyone in
the airplane will get sick in a hurry.
Another classic demonstration of limitations in the ball was done by William
"Bill" Kershner. He placed two slip/skid balls on the instrument
panel, one each in front of the two seats of a Cessna 150 Aerobat, and one if
front of each seat in a Beech Aerobatic Sport. He then proceeded to do some
spins.
The two balls in each airplane were in opposite corners of the inclinometer--one
to the left side, one to the right side. This is why during a spin, the ball
cannot be used to determine which rudder to step on for recovery.
As a variation of this, I routinely perform the classic skidded base-to-final
turn into a spin (at altitude of course). As part of the demonstration, I often
have the student look at the ball when I feel we are 1/2 second from spin entry.
The ball actually straddles one of the two lines that we use to know where
"centered" is.
In other words, even though we are within 1/2 second of spin departure in the
skidded turn, the ball is only 1/2 ball out of center. It clearly is not
indicating how close we truly are to the impending spin
departure.
In fact, if we couple that left skidded turn into a spin with Kershner's
experiment, we can imagine that prior to spin departure from a left skidding
turn, both balls--the one in front of the pilot in the left seat, and the one in
front of the pilot in the right seat--are off to the right of center somewhere.
But as we get closer and closer to spin departure, the ball that will eventually
be on the left side of the inclinometer in the left spin begins to move from the
right to the left. Suppose it is just this ball that you have in your airplane.
And even though you are skidding to the left, the ball eventually begins to move
from right to left as you approach spin departure. At T-minus 1/4 second from
spin entry you glance at this ball. Lo and behold, it's centered! Not really,
it's just en route to the left as the airplane enters the spin. It just so
happens that when you looked at it, things were apparently "lookin'
good!" from a ball standpoint.
An obvious demonstration of another one of the ball's inherent deficiencies is
to roll the airplane to 180 degrees of bank--inverted flight--and see if the
ball will stay on what is now the top of the hump of the inclinometer while you
are in coordinated inverted flight. The ball cannot stay on the hump, and falls
off to the side (though there is an air bubble that lives in the
inclinometer--usually you can't see it in upright flight, but it makes itself
known when inverted. One could, if one were so "inclined," look to see
if the air bubble is centered to confirm coordinated flight!).
The best advice I was ever given about the ball -- stop staring at it!
(Unless you are in IMC, that is, where we must rely on our instruments. BTW,
when we are in IMC, we do everything we can to keep the airplane as close to
wings level, steady flight as possible so that our instruments will give us as
close to real time information as possible--quite a bit different from VFR
flying...)
Fly the airplane and control yaw by sight (look at where the nose is going vs.
where it should be), sound (propellers on Cessnas groan when you are
uncoordinated), feel (in the seat of your pants), and aeronautical knowledge
(climbing flight requires some right rudder, descending flight requires some
left rudder, slow flight requires some right rudder, etc. -- we know this
intellectually based on the aerodynamics of flight in light airplanes).
Use the ball only to confirm and/or fine tune what you are already doing in
terms of yaw control based on sight, sound, feel, and aeronautical knowledge.
Oh, and to sense yaw accurately, you must not be leaning all over the place in
your seat while you are maneuvering. You must learn to keep your body
aligned with the airplane, NOT the horizon outside. If you are always
leaning in your seat to stay "vertical" to the horizon, your body will
not be aligned with the airplane's yaw axis and it will be much more difficult
to sense yaw. Be safe,
Rich Stowell
Manifold Pressure
The Problem
I know that manifold pressure means the pressure inside the intake manifold, but
I'm confused about what this really means, and what it has to do with throttle
settings and engine power.
When the engine is off, the MP guage measures ambient air pressure (usually
between about 29 and 31 inches of mercury), right?
(1) Why does the MP go DOWN when the engine is turned on? What is it about
running the engine that causes the pressure in the intake manifold to drop?
(2) Why does the MP go UP when you increase the air/fuel mixture being fed to
the engine by opening the throttle?
(3) Why, in an Arrow, do you get 65% (117HP) at 2300 RPM with 22.8 MP at sea
level (pressure altitude) and the same power at 2300 RPM with 20.6 MP at 9,000?
(4) Why do you get 65% at 2100 RPM with 24 MP and the same power at 2400 RPM
with only 22.2 MP?
(5) The Arrow POH says to add .17" Hg for each 10deg F by which carburetor
air temperature (this on an airplane that's fuel injected and doesn't have a
carburetor) exceeds the standard temperature. Why?
Stephen S. Ashley
Advice
The only reason your engine operates at less than full power is because the
throttle "chokes" the engine and denies it the air/fuel it wants.
An engine would normally run 100% power if the throttle didn't "choke"
it. If you open the throttle all the way you simple stop "choking" the
engine (allow ambient pressure in) and it runs at it naturally wants to.
R.M. Gary
Advice
(1)
The cylinders are essentially a big air pump. Think of it like a syringe. When
you pull back on the intake stroke it sucks in air through the open valve. Then
the intake valve closes for the rest of the cycle on that cylinder. The fact you
have several of them doing this a few thousand times a minute keeps the pressure
low (against the closed throttle plate).
(2)
You're letting air into the system by opening the throttle. This causes the
vacuum to get out (er, um) the pressure from outside to get in.
(3)
Density of the air. You get less oxygen at higher altitudes.
(4)
Horsepower is determined by the torque (force of the rotation of the engine)
times the speed. So you can either have the engine turning gently at high speed
or hard at low speed to achieve the same output
power.
(5)
Density of the air. You get less oxygen with higher temperatures.
Ron Natalie
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