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Flying Airport Patterns
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Contents
…Airport Pattern Authority; ...Pattern
Safety;...Takeoff/Pattern
Procedure; …Why 30- degree Banks;
…Patterns Using the Heading Indicator;
..Landing Suggestions; ...Airport
Procedures; ...Pattern Skills; ...Airport
Arrivals; ...Two-Mile
Reports; ...Airport departures; ...Class D Airport Departures; ...Noise
Abatement; ...Flying the Pattern; ...Cessnas
In the Pattern; ...Difficult Patterns; ….Approach; …Traffic
Patterns; …Pattern
Diagrams; …Traffic Watch;
...Seeing; ...Seeing
What You're Looking For; ...Runway Lights;
...VASI; Tri Color VASI; ...
PAPI; ...Short Approach; ...Short-Short
Approach; ...Decelerating Approach; ...Extending
Downwind; ...Why Patterns Are
Different; ...On Making
45-degree Entries to Runways; ...Conflicts
of Arrivals and Departures; ... Uncontrolled
Airport Arrivals; ...
Airport
Pattern Authority
Except for traffic conditions where ATC (Air Traffic Control)
has override powers, airport pattern directions, and altitudes
are decided by local jurisdictions. It is often difficult to
find out just why a particular local rule exists. I know of an
airport where a 10 degree heading change was required shortly
after takeoff. This requirement existed years after the original
home and person making the turn necessary were long gone. Much
like the 7000' winds aloft figures that existed for years only
because it had always been there.
Pattern Safety
It is a matter of self-preservation that the pilot should
be aware of the world around him. What we hear over the radio
and from the airplane gives information of varying significance.
Out eyes should tell us of the signs of wind direction and velocity.
(ATIS can be an hour old) Wind acts as a weather forecaster.
Learn to read the wind. What we see serves as a double check
to confirm existing conditions.
When traffic gets heavy you can sense when the controller is getting behind. He may mention the number of planes he's working or tell someone to remain clear for a few minutes. You can help the situation by going elsewhere, offering to change runways or making a full stop.
Separation is the controllers sequencing problem and the pilot's responsibility is to fly a pattern size and speed that will make the ATC system work. Being under ATC control does not relieve the pilot of his see and avoid responsibilities. The pilot MUST not rely on the controller for separation. Ask the controller to call your traffic, base turn, or spacing maneuver or get approval to do these on your own. The vigilance of the pilot in a controlled pattern is just as important as in an uncontrolled pattern.
Knowing where to look is a big part of the pilot's solution. Knowing checkpoints is not just for your arrival and departure and radio procedures. Knowing checkpoints allows you to be sensitive to where a traffic conflict is likely to occur and then gives you options for your taking avoidance measures to help ATC. Little things, like going to slow flight, offering to change runways, squaring your pattern, or requesting a 360 can take the pressure off the controller. One 'idiot' in the pattern can make it difficult for everyone.
Any accident you have in an airplane is almost certain to
be ruled by the FAA as a violation of the FARs. FAR 91.113(b)
says, "When weather conditions permit, regardless of whether
an operation is conducted under instrument flight rules or visual
flight rules, vigilance shall be maintained by each person operating
an aircraft so as to see and avoid another aircraft. " FAA
lawyers have written and interpret the ambiguity of all the FARs.
The standards of see and are seen vigilance is absolute in that
if you have a midair accident you were not vigilant. The maintenance
of "perfect no accidents ever" vigilance exceeds possibility.
The courts have had more reasonable interpretations of the absoluteness
of this FAR vigilance requirement.
Takeoff/Pattern Procedure
Standard operational procedure requires that no turns are
to be made during takeoff until reaching the end of the runway
unless ATC directs otherwise. There is a safety reason for this
since it avoids traffic conflict in aircraft entering on the
45.
Why
30-degree Banks
If a 30-degree bank is safe, 20-degree is safer. Not so.
Is a limit of 20-degrees in the traffic pattern being over cautious?
There is no significant increase in load factor at 30 degrees,
you still have sufficient of margin for error, and you will soon
become comfortable with that bank. (1.15Gs)
One of the very first flight lessons I give consists of a demonstration/student performed 30-degree hands-off banking circle. I prove to them that the 30-degree bank is the most stable of banks. Any bank angle of more or less than 30-degree requires the application of opposite aileron to counter the inherent stability of the aircraft for the 30-degree bank. I do teach some cross-control Dutch rolls and stall entries but I do not want them being performed in the pattern at pattern altitudes. By trimming for the level 30-degree turn, (1/2-turn down) the angle of bank can be held very easily with the rudder. Every student should have this experience.
A related experience for the student is to trim for level flight and make some rudder-only turns at shallow angles. One of the learning experiences from such turns is the demonstration that leveling the wings will cause an increase in altitude. This explains the necessity for anticipatory thumb pressure on rolling out of turns.
The major objection to 30-degree banks has to do with the discomfort that they give passengers. Much as landing on one wheel in crosswinds can and should be explained to passengers, so should the 30-degree bank be explained. The fact is that a 30-degree bank has a negligible increase in g-loading of only 15/100-ths of a g.
I first came on the problem of the shallow pattern bank when controllers complained to me that it was often very difficult to tell if a aircraft's wings were just being held one-low, wobbling, or turning. A low wing can take 100 fpm off the rate of climb. There is no intrinsic greater safety in a 20-degree bank over a 30-degree bank for the flying student.
It is far more important in the pattern for the student to maintain airspeed and coordination. Banking more or less than 30 degrees is acceptable as long as excess rudder is never used to increase the rate of turn. This is an IFR standard rate turn device on instrument approaches sometimes known as ruddering-it-around that is not a part of this learning situation.
While 45 degrees coordinated bank has no basic problems you are not leaving enough margin for error. Should a distraction occur that causes an additional bank increase and possibly a slowing or lack of coordination. The stall speed in a 45-degree bank is only slightly less than normal approach speed. Not much less, but less. Stall speed is unpredictable in a skid, and it is very likely that only the trailing wing will stall. When the wing drops, instinctive use of the aileron to pick it up will only aggravate the stall and most likely turning it into a spin.
Patterns
Using the Heading Indicator
I was a math teacher for many years and used to teach the
kids how to do tricks with numbers. The sum of the digits is
just a shortcut for knowing when you have turned 90-degrees.
360 if you add to get the sum of the digits gives 3 + 6 + 0 =
9. 90-degrees to the right you get 090 = 9. Another 90 degree
turn gives 180 or 1 + 8 + 0 = 9. Next turn gets you to 270 2
+ 7 + 0 = 9.
The sum of the digits works for all other headings that are 90-degrees from another. It is just an easy way to remember the number you are turning to when most of your turns are 90-degrees. If I recall correctly Auburn's primary runway is 25. In flying a no-wind pattern you would take off on a heading of 250. 2 + 5 + 0 = 7. Your left crosswind heading would be 90-degrees to the left or 1 + 6 + 0 = 7. Your downwind left turn would be to 070 = 7 and base would be to 340 3 + 4 + 0 = 7. This is quite easy to do by looking at the heading indicator.
The numbers on the heading indicator are a great help when you are making a base entry at a controlled airport. For right base the runway number will be to the right side of the HI. For a left base the runway number will be to the left side of the HI. When entering a left 45 entry for 25 at Auburn the runway heading will be at the lower left 45 position of your HI. This works for all runways and all airports. It makes making 45 entries to downwind much easier.
For most compass numbers the reciprocals can be quickly obtained when the first digit is 0 or 1 by adding 2 to the first digit and subtracting 2 from the second digit. When the first digit is 2 or 3 subtract two and add two to the second digit. Third digit is always the same.
I've had a number of students express interest in the sum-of-the digits relationship between all the compass numbers that are 90, 180, or 270 degrees from a given number. I find this quite helpful when making pattern turns.
030 = 3...... 060 = 6
120 = 3....... 150 = 6
210 = 3 .......240 = 6
300 = 3 .......330 = 6
It even works on
045 = 9
135 = 9
225 = 9
315 = 9
Landing Suggestions
--On downwind pick a go-around point for the runway
--Rig every preflight with a discrepancy
--Use the squat test after your preflight
--Every takeoff contains an abort
--Every landing contains a go-around
--Use a tape recorder
Airport Procedures
In the pattern you should not turn crosswind until within
300' of the pattern altitude and only then when beyond the departure
end of the runway. On departing the pattern you should not make
your departure turn until at pattern altitude and beyond the
departure end of the runway. At tower airports any directive
by ATC can supersede any of these standard procedures.
A major consideration when arriving at an airport is to make
your arrival direction and altitude one that provides maximum
separation. Avoid the departure end of the runway and the associated
departure paths. For this reason I am a strong advocate that
all 45 entries be pointed toward the approach end of the runway
and not the departure. Low-wing aircraft should be at pattern
altitude when entering on the 45 while high-wing can optionally
be descending for improved visibility. Regardless of the area
of instruction a pilot can always perform better when they understand
why they are doing as they do. Safety is a continuous process
that has a great deal of influence on the outcome of every flight.
Pattern Skills
How does a pilot become familiar on a first arrival at a
strange airport? You look for references both inside and outside
the aircraft. You use the heading indicator to determine the
downwind heading, the base heading, the runway heading, and the
upwind heading. You look out away from the airport and pick visible
targets that can be referenced to the airport. With practice
you can become skillful in this at any airport. Unless you practice
it you will continue having pattern problems.
Additionally, you can learn to reference a particular row of
rivets on the wing or a strut point with the centerline of the
runway while in level flight. Using the centerline is a way to
overcome the optical effects of different sized and proportioned
runways.
If the downwind is flown appropriately to the wind conditions
there will variations of distance from the airport laterally.
A crosswind that is blowing you into the runway will require
a wider pattern track than will the wind that is blowing you
away. The strong wind right down the runway will require a tighter,
closer base turn than will a calm wind condition. The 'calm'
wind condition will usually consist of several variable winds
that change both direction and velocity throughout the pattern,
approach and flare. To the extent that winds are abnormal in
direction and strength the pilot must make compensation adjustments
to the pattern flight path.
An essential to flying a landing pattern is climbing or descending
to an altitude and accelerating to cruise at that altitude. Failure
to master the visual clues for level flight, the sounds of specific
airspeeds, and the trim position in the C-150 will cause transition
problems with higher performance aircraft. The standardized airport
pattern cannot be flown correctly unless the pattern altitude
is constant. You must be able to level off at altitude every
time with a minimum waste of motion or time. While doing this
relatively simple but hard to master procedure you must correct
for winds so as to maintain a pattern suitable for landing and
traffic avoidance. A traffic pattern is the four basic flight
skills being put to use.
Airport Arrivals
One of the most critical phases of all flying is airport
arrival. The fact that radar is becoming increasingly available
makes many arrivals more controlled and seemingly easier. Just
be aware that proper radio procedures are critical in the radar
environment. The existence of radar makes non-radar arrivals
less frequent and familiar. Regardless, always get the ATIS,
communicate from known (pre planned) check point 10 to 20 miles
out. If you are unfamiliar, so advise ATC. Doing so is a sign
of competency. Only incompetents try to fake it. Request to over
fly above pattern altitude if you are at all uncertain as to
how make your entry. Perhaps the most dangerous of all flight
situations is to make an airport arrival incorrectly. If you
are at all uncertain, go to "slow flight" and GET HELP
from ATC. The willingness and readiness to admit the need for
help and to ask for it is the ultimate sign of flying maturity.
Only the incompetent pilot thinks he is supposed to know everything
and is consequently reluctant to ask for help.
To a single runway there are seven standard arrivals. There are
two non-standard arrivals that are relatively hazardous. If no
special considerations interfere any of the seven may be requested.
If the pattern direction is known a 45-degree entry into the
pattern need not be requested. However, the tower must be advised
that you will report right or left downwind. As a standard procedure,
except for the downwind entries, all other arrivals require a
two-mile report unless otherwise advised. The purpose of the
report is to allow the tower time to locate you and plan a safe
sequence for your arrival.
1. Straight in
2. Right base
3. Right downwind
4. Right standard (45)
5. Left base
6. Left downwind
7. Left standard (45)
8. Direct entry to left downwind (not recommended)
9. Direct entry to right downwind (not recommended)
All of these can be modified by pilot request or ATC suggestion.
A modified entry may be at other than a precise number of degrees
relative to the runway. I recently heard an aircraft over the
airport request and be approved for an overhead arrival. Ask
and you may receive.
A typical call might be..."Podunk tower Cessna 1234X the
dump at 2100 with Alpha request right base 32 will report two-mile
base" Again, no punctuation should be used when writing
or talking airplane.
The standard 45 entry has some dimensions that can be used to
standardize a landing approach. The ideal towered runway is about
5000', close to a mile. Entering on a 45 and aiming at the runway
threshold and turning downwind at mid field would place the aircraft
a half-mile from the runway and a half-mile from abeam the numbers.
Flying from the numbers to the 'key position would be another
half-mile. Base would be a half-mile as would the final. This
gives the aircraft a two-mile landing procedure with the first
half-mile for pre-landing procedures, the downwind extension
for slowing, trimming and configuring the aircraft, the base
leg for descent and setting the length of the final approach.
The two-mile reports for the straight in and base arrivals can
be segmented much as the standard arrival and used to organize
your landing procedures.
Two-mile Reports
The two-mile report should be 'measured' from the runway
threshold. the 'measuring can be done for the straight-in by
using a known site directly in line with the runway or by using
a call that says abeam (beside) a known site. The last recourse
is to visualize the runway flipped toward you two times. If you
use GPS, you should know the point on the airport used as its
position and adjust your GPS reading accordingly.
The two-mile base reports can be done much the same as the straight
in except for the use of the runway flips. Your entry line should
be aimed at a point anywhere from a quarter to a half-mile before
the threshold.
There is an instance where the 45 entry and two-mile reports
can and do present pilots with illusions that can affect their
airport arrivals and landings. A pilot using the 45 entry at
a runway of 3000' or less should plan to turn downwind abeam
the departure end. Flying to midfield before turning will reduce
all the flight segments to 1/4 mile. The best way to see this
effect is to compare the pattern of a 5" drawing and a 3
inch drawing of a 45 entry. The best advice I have for flying
a pattern at a small or unfamiliar small airport is to keep the
downwind twice as far as you think you should and you will be
about right.
Where parallel runways exist, any requested departure may be
restricted by ATC until they authorize a turn for reasons of
conflicting traffic. At any airport, a particular departure may
by limited because of terrain, noise abatements, or local considerations
where turns are only allowed after reaching a particular point
or altitude. Every airport will usually have a place where the
preferred or prohibited flight procedures are explained and/or
illustrated.
Intersecting runways make possible restricted clearances to land.
The restriction most often requires the pilot to land and hold
short of the intersecting runway. A pilot should not accept such
a clearance unless able to comply.
I have read that worldwide the average wind has a velocity of
about twelve knots. At each end of this reference are wind extremes
that can and do cause pilots pattern and landing difficulties.
One extreme the strong winds are expected while the other extreme,
the so-called calm wind, has unexpected capabilities. A student
should be exposed early to runways of varied widths and lengths
in both left and right patterns Each of these extremes offer
specific problems that can be solved only by a varied exposure.
Once exposed a pilot will better avoid problems by using the
skills of anticipation he has acquired.
Airport
Departures
The departure from an airport begins with the preflight,
progresses through the run-up, and to the entrance of the runway.
The first step in any departure is to clear the approach area.
This includes the close-in base from either side. There are several
different takeoffs and each of these have variations. (See Takeoffs)
The normal takeoff is an early lift-off and climb at Vy, which
is the usual noise-abatement climb and gives the most altitude
over duration of flight.
The initial climb is normally straight out until reaching a locally
determined altitude at which turns are permitted. At the turn
altitude all the departure options exist. Common departures are:
1. Straight out
2. Left/right standard 45 degree
3. Left/right crosswind
4. Left/right downwind
5. Left/right 270
To all of these can be appended the term "on course...destination.
This 'on course' has the advantage of being more precise as to
direction. This means that ATC and other listening aircraft will
have a better means of finding you. During the climb you should
be varying your heading so as to clear below your flight path
Never make a turn without first clearing. When you level off
select an altitude within 3000' AGL (Above ground Level) that
avoids thousands and five-hundreds. The airport departure is
second only to the landing as a hazard area.
From a single runway there are nine standard departures that
may be requested if there are no special considerations. If departures
can be made from both ends then we have a total of eighteen.
If left traffic is standard there are two of these eighteen that
need not be requested. They are the two left standard (45 degree)
departures, one from each end. If no request is made you are
expected to make a left standard departure. The tower may ask
for confirmation of as standard departure just to make sure.
From any ATC controlled runway you can request a...(they can,
also, say no......on course (destination) may be appended to
any of these. A low visibility or weather related departure would
be to request a climb in the pattern.
The crosswind takeoff requires a distinct set of procedures from
the crosswind landing. You hold the yoke full over into the wind
and maintain directional control with the rudder. Keep the aircraft
firm on the runway until reaching just short of normal lift off
speed. Level the yoke, pop the plane into the air and apply rudder
to crab into the wind while flying in ground effect. I do not
believe that partial aileron has any particular advantage in
this sequence.
Runway heading is the magnetic direction that corresponds with
the runway centerline extended, not the painted
runway number. When cleared to "fly or maintain runway heading,"
pilots are expected to fly or maintain the heading that corresponds
with the extended centerline of the departure runway. Drift correction
shall not be applied; e.g., Runway 4, actual magnetic heading
of the runway centerline, fly heading.
Class-D Airport Departures
If no request is made you are expected to make a left standard
departure. The tower may ask for confirmation of as standard
departure just to make sure.
From any single runway you can request a...
--straight out
--left crosswind
-- left downwind
--left 270
--right standard
--right crosswind
--right downwind
--right 270
You can just say request left/right turn on course (destination) The advantage of naming a destination is that other aircraft are given a more specific idea of the flight line you will be flying. A low visibility or weather related departure would be to request a climb in the pattern.
Typical call would be..."Podunk tower Cessna 1234X ready 32 request right 270 on course Lost Hills" No punctuation should be used in talking or writing airplane.
Noise Abatement
The FAA lets local jurisdictions set patterns as to altitudes,
direction, minimum turn altitudes, routes, etc. Once saw a Swiss
airport diagram which directed avoidance of individual homes,
groups of homes and buildings in such a manner that the airport
pattern resembled a sports car racetrack.
At Concord different runways have different local rules and preferences. Left turns off 32L are prohibited until past the second set of railroad tracks. No turns are allowed below 600' AGL. No descent is to be made (recommendation) until turning base on any runway. For noise abatement one runway direction may be designated at the landing runway while another runway direction is used for takeoff. Only a certain number of planes are allowed to be based on the field. There are four assigned arrival and departure routes for helicopters. Inside the Class D airspace they are to maintain 600' AGL. When the tower closes, left patterns are flown even for right runways. This last item varies among airports.
There is no one source for a visiting pilot to find this information. The A/FD has several items such as hours of operation, pattern altitudes, and after-hours procedures. The runup areas have signs with special instructions for departing aircraft and pattern turn altitude minimums. The airport lobby will often have noise-abatement diagrams showing routes to use for high sensitivity area avoidance.
The airport (CCR) is surrounded by noise sensors, which can be cross-checked with a particular time and aircraft on the ATC tapes when someone in the area makes a complaint. Places like SFO have an automatic alarm system on its sensors where the tower is notified when a certain decibel level is exceeded.
The root problem is the permitting encroachment of homes on airport flying space. Because of the 'noise' the land is relatively cheap. Once enough homes are built the 'noise' becomes a political problem. Pilots who learn to fly at airports where noise is not a problem tend to slow down before reaching the numbers and then descend at the numbers. This type of pattern is not accepted at airports like CCR. It is relatively common to be told to extend your down-wind at CCR because of traffic. For that reason, among others, The downwind altitude is supposed to be maintained. (Pattern used to be 800')
A very minor adjustment in landing procedure makes the 1000' pattern work quite well. Cruise speed is maintained until the numbers. Altitude is maintained until deceleration to approach speed. Interestingly, this sets beautifully Cessna 45 degrees for the 'key' position turns to base.
Flying the Pattern
There is a helpful logic behind Concord's ATC always requesting that
you report a two-mile final or two-mile base. A 45-degree entry
to downwind to a mile-long runway would allow a mid-field downwind
turn 1/2-mile from the numbers. A 45-degree entry to downwind
to a shorter runway should be made at the departure end to prevent
the optical illusions that lead to close-in downwind patterns.
With a half-mile to do the pre-landing before reaching abeam
the numbers, another half-mile to slow down and reach the key
position, still another half-mile base, and a half-mile final
we have adapted the ATC two-mile base and straight-in call-up
distances to the basic downwind entry.
In the landing practice pattern the takeoff and climb to downwind
can be just a precise as any other part of the pattern. The lift
off occurs at Vso or slightly higher in crosswind conditions.
Climb is delayed until Vy unless Vx is a requirement. Runway
alignment is maintained with crab as appropriate with at least
one visual check around 300 feet. Takeoff ranks #2 behind landings
as a source of accidents. You can't achieve a successful landing
without first making a successful takeoff.
The turn to crosswind is initiated after visually clearing the
turn area and selection of a visual or heading reference. In
the turn the eyes and head are not turned but are used to maintain
attitude, bank and airspeed until the visual point comes into
view. Very slight forward pressure is used both during entry
and recovery from turns if a constant airspeed is to be maintained.
At the thirty-degree point of bank, backpressure is used to maintain
airspeed. All climbing turns are with coordinated controls at
altitudes according to local practices at Vy. Entry and recovery
from the turn bank is coordinated with anticipated rudder and
aileron as required by the direction. Begin turn recoveries 15
degrees early. Left and right climbing turns are significantly
different and should be practiced equally.
Just where the turn to downwind occurs is usually determined by wind and terrain conditions but occasionally traffic may require turns sooner or later. The width of the downwind must be adjusted wider for any wind that blows the aircraft toward the runway and closer to prevent a wind from blowing the plane too wide. This downwind adjustment is a critical flight positioning of the pattern, which can only be made with repeated exposure to varying conditions. A short base is a prelude to tragedy.
Leveling the aircraft at pattern altitude and anticipating the amount of trim required must be done according to the downwind speed desired. There is no one best way to select this speed. My personal preference is to use level cruise speed for several reasons. Trainers are the slowest aircraft in the air. Using a slow trainer speed downwind places unfair hardship on non-training aircraft in the pattern. The cruise speed is a familiar trim, power, and sound condition. The reduction of power at the numbers while maintaining heading and altitude gives a relatively constant key position for the base turn. Most urban airports require (request) that pattern altitudes be maintained until turning base. This technique allows each aircraft to select its pattern key position according to its performance.
Base to Final Turn
Fly wider from small, unfamiliar runways
Any crosswind will affect the way you fly the downwind
Most hazardous is crosswind that blows you toward the runway
DOUBLE the distance from runway to avoid the short-base
killer turn
Practice both left and right crosswind patterns to the same runway same wind
Any time you have a tailwind on base you are looking at trouble
It is your habitual peripheral vision that causes the problem. It senses a
faster than normal speed causing you to raise the nose and slow the aircraft.
The higher ground speed overshoots the turn to final. You make a steeper turn
to final. Steep turn + low speed + rudder assist = instant spin.
By doubling your downwind distance, you double your base leg, you can lead your turn to final and keep the wing down with opposite rudder for your ˝ Dutchroll wing low approach.
Making Friends in the Pattern
---Learn how to correct for the problems created by others.
---Instantaneous slow flight when #3, conflicting base traffic or on extended
downwind.
---Learn how to make short and short-short approaches with and without flaps
---You slowdown to get down
---Slower reduces turn radius and shallower bank angle for S-turns and
maneuvers
---Slower final provides more options
---Slow flight skills are required in the pattern
---Practice flight changes from slow flight to cruise and back with turns.
---Use the same procedure and sequence for a straight-in as for a regular
pattern
---Two airplanes can be on the same runway, ATC requires 3000’ intervals
Cessnas
in the Pattern
The preflight includes checking the trim setting. The trim setting
left by the previous pilot is very revealing about such 'little'
things as CG, use of flaps and the landing itself. When I find
the trim 'off' I like to see what the nose strut tells me.
A C-150 that landed with full flaps and an approach speed of 60 knots, 1500 rpm, hands-off will be trimmed for level flight so takeoff Vy requires one full turn of 'nose up' trim. This was designed into the C-150 but not into the C-152.
The C-172 with 40-degrees of flaps has much the same design relationship between power, trim, and flaps. On final with full flaps, 1500 rpm and trimmed hands-off at 60 knots, the C-172 will be correctly trimmed for a Vy takeoff once the flaps are taken off during rollout.
With slight changes the older C-182 can be flown much the same way. When Cessna began making changes in all these models the engineering purity was lost. For the C-152 they came up with the no-trim-needed method for flying the patterns.
As I was taught by a Cessna FBO's Chief Instructor Pilot---:
Prior to take off set the trim index for takeoff. Just before
reaching pattern altitude, reduce the power for level flight.
Abeam the numbers reduce the power to 1500 and put in 10 degrees
of flap. Speed falls to 70 knots...no trim required. When ready
to turn base put in next 10-degrees of flaps during the turn
and speed will fall to 65 knots...no trim required. On turning
final put in last 10-degrees of flaps during the turn and speed
falls to 60 knots...no trim required. Flare, touchdown, clean
up flaps and add power for takeoff ...no trim necessary. I can
do it BUT I won't teach it that way.
As a ras contributor taught me several years ago...Trim is the cruise control of flying.
Difficult
Patterns
I have read that worldwide the average wind has a velocity
of about twelve knots. At each end of this reference are wind
extremes that can and do cause pilots pattern and landing difficulties.
One extreme, the strong winds, is expected while the other extreme,
the so-called calm wind, has unexpected capabilities. A student
should be exposed early to runways of varied widths and lengths
in both left and right patterns Each of these extremes offer
specific problems that can be solved only by a varied exposure.
Once exposed a pilot will better avoid problems by using the
skills of anticipation he has acquired.
The real cause of stall/spin accidents is usually blamed on control coordination and speed control. I would content that the problem has more to do with a failure to fly an airport pattern such that the control coordination and speed control will not become a problem. My argument is supported by the fact that nearly two out of every three approach accidents occur as a result of a steep turn/stall.
A spin will not occur until an excessive angle of attack is augmented by yaw. The demonstrated deliberate stall is in no way similar to the accumulation of numerous small errors in the flight pattern that total the spin entry with no chance of recovery. Flying the correct pattern is the best spin preventative that can be taught. The spin occurs only when the pilot finally realizes that the pattern is inappropriate and begins making what are the only options for correction. These options are excessive bank, excessive rudder, excessive elevator, and crossed controls that in combination precipitate the spin.
The final twenty seconds of the pattern are the result of almost five minutes of pattern flying. Flying the pattern at several thousand feet to simulate the stall/spin entry scenario is not realistic. I feel it is better to walk the patterns on the ground to show how the crosswind that blows the plane into the runway on downwind will lead to the stall/spin situation. Then go and fly the pattern in such a way that you correct the problem from the upwind through the rest of the pattern. I always try to make both left and right patterns to parallel runways when possible. One crosswind blows you away from the runway and the other into the runway. The proper crab on upwind, crosswind and downwind will set up the base leg that will make normal 30 degree banks and airspeeds set up the final.
When you overshoot final accept it as leading to a stall/spin
situation. If you are in tight, make a go-around. Otherwise,
hold the turn and accept a gradual interception to final. Exposure
to the cause in training is the
best avoidance cure I know.
Some mountain/hill airports require that you fly relatively close to one side of a mountain/hill on your downwind in order to give your pattern an adequate base leg. The flatlander pilot will find this uncomfortable and fails to fly as close as is necessary. If this stricture applies to you, you should get some instruction or better yet do some ridge flying in a glider.
Approach
(instructor)
The older technique of power off had some inherent dangers.
Power off landings can shock-cool the cylinders. Carburetor heat
will become ineffective as the engine cools. Full power will
need more careful application to prevent loading up the engine.
I very much recommend that the landing approach and flare be
made with power. There is usually a decrease in the wind near
the ground. This causes an increased sink rate. By carrying power
this increase in sink rate is not a problem. Power allows you
to raise the nose with the added elevator authority provided
by prop wash over the control surface. At 1500 rpm considerable
float is available in ground effect. Reducing the power in increments
of 100 rpm can be used to control the float and touchdown point.
Leaving the power on allows a very controlled soft-field landing.
From level cruise in the C-150, if power is reduced to 1500 and speed reduced to 60 kts, three full downward turns of trim will hold that speed after deceleration in descent. (The same procedure will trim out the C-172 at 70 kts.) Ten degrees of flap will cause the nose to pitch up and speed go to 50 kts. One full upward turn of trim will return you to 60 kts. If you hold the nose down while putting in ten degrees of flap and then trim up one turn the airspeed will remain constant. The same process holds true when an additional 10-degree increment of flap are added. 30/40 degrees of flap requires only one turn.
This engineering of the flaps is essentially why a C-150 can be flown without using trim. And why it is possible to find (poor) instructors who teach flight in the C-150 without the use of trim. If you don't trim for slowing down you don't need to trim for adding full flaps. Thus the short approach procedure does not require trim. If you do trim for slowing down and add flaps you must retrim and you are back to where you started--trimmed for level flight in the C-150. The student who does not trim for every configuration will be severely handicapped in transitioning to higher performance aircraft.
Starting at an even hundred within 3000' of terrain and on a cardinal heading have the student pull carb heat and reduce power to 1500 while holding heading and altitude. (This should be easily done since it conforms to many of the previous entries) Move the trim wheel from the top button down three full turns for a trimmed speed of 60 kts. Check the trim by letting go of the yoke. (Be sure to let the student knows that you are setting up a descent.) Make successive left and right 30-degree banks to 90 degrees. (Of course, we clear before every turn!). Have the student anticipate the need for forward yoke pressures when entering the bank. Lead with right rudder in right turns. Apply slight backpressure when in the bank and slight forward anticipatory pressure when coming out of the bank. Lead with right rudder coming out of left banks. We are working for accurate airspeed control at 60 kts.
Once reasonable proficiency is acquired making these descending turns without flaps we are ready to add flaps. On a cardinal heading and descending at a trimmed 60 kts have the student add a count of 1-2-3-4 with the flap switch. Dampen the pitch up with the yoke and allow the speed to stabilize. It should be at 50 kts descending. Move the trim wheel up from the bottom button one full turn. Dampen the pitch down with the yoke and allow the speed to stabilize. It should be at 60 kts again. Show that there is a one-to-one relationship between 10 degrees of flap and a full turn of the trim wheel. Trimmed without flaps at 60 kts and 1500 rpm you can hold the nose with the yoke while putting on 10 degrees of flap and taking off one turn of trim and maintain the same speed as trimmed hands off. (It may be necessary to climb back to altitude several times during this procedure.)
At altitude again, repeat the process from a cardinal heading. Reduce power and trim for 60 kts. Make left and right banks as before without flaps. Add 10 degrees of flap and trim for 60 kts. Again make left and right 30-degree banks to 90 degrees. (The student should be advised that as the flaps are added a slightly greater anticipation and pressure is required both with rudder and yoke throughout both turns and leveling out.) Add 10 more degrees and trim again for 60 kts. (One turn of trim.) Again make left and right turns. When we first slowed up we trimmed down three times. Now as we put in the remainder of the flaps we will take off (up) one full turn. The trim is now back as though at level cruise but with full flaps. We make left and right 90-degree turns and are given a 'go-around' altitude. There are no dumb go-arounds
This suggested landing procedure is only one of many. It has, however, some inherent advantages. A constant air speed that is obtained, with very small variations, by a set pattern of trim and flap positions that will carry over to all Cessnas. Good trim skills will readily transfer to high-performance twins. The use of a count, where indented flap positions are not available removes the flap indicator watching otherwise called for. In addition to well planned/flown landings the student should be exposed to errors of planning and the acceptable corrections. The ability to correct mistakes is even more important to landings than having everything go smoothly. The safe correction of a planning error requires greater skill than does doing it right in the first place.
Traffic
Patterns (Instruction)
Take two separate pieces of papers. Draw to scale a runway
1-mile in length on one and a 1/2-mile runway on the other. Draw
a 45-degree entry lone to both runways and the downwind turn
point at mid field for both. What we are trying to illustrate
is why the inexperienced or unfamiliar pilot is usually too high
at a small airport. A two-mile straight in approach should be
drawn and divided into four 1/2-mile segments. Use this to show
how the sequencing of events of the normal 45 entry is related
to the straight in. Additionally, inexperienced pilots become
tense at small strange airports and tend to fly closer tighter
patterns due to failure to compensate for the perceptual differences.
On the larger diagram, the midfield turn to downwind give a half-mile for prelanding to the numbers, a half mile extended downwind to the key position, a half mile base leg, and a half mile final. This pattern, straightened, is the same length as the 2-mile straight-in approach and the 2-mile base call often requested by ATC.
The same approach used at a smaller field results in only a one-mile pattern and an approach too high to land. This is a frequency occurring illusion at unfamiliar small airports. The solution I suggest is that, when entering downwind at a small or strange runway, you should fly twice as far out from the runway on downwind as seems optically correct. This is particularly important if right traffic is required. the desire to keep the runway in sight. When the downwind is too close the desire to keep the runway in sight causes the pilot to keep the right wing low and to gradually turn ever closer to the runway. This can lead to a short base leg and a stall/spin while turning final. By flying twice the perceived distance on downwind at small airports you will be about right.
Using the same runway patterns, now draw a wind arrow at right angles. Draw in a number of small airplanes to illustrate the required headings and the degree of turns necessary to keep the aircraft the normal distance from the airport. Draw the patterns in both left and right traffic so as to illustrate the effect of the downwind turn on base and crosswind turns. Emphasize that the turns to final between the left and right requires a completely different application of rudder and aileron to set up the half Dutchroll cross wind correction.
Draw additional patterns (red) to show how failure to maintain downwind lateral distance can result in getting too close and tight to the runway prelude to a spin entry. This is most likely to occur at a strange, small airport where visual references have not been established.
At CCR the noise abatement landing procedure is that no descent from pattern altitude (1023') be made until turning base. While slowing an aircraft prior to downwind entry may be initially beneficial for instructional purposes, it creates attitudes and habits that are inefficient, expensive and lacking in flying courtesy. Don't slow down the system by flying inefficient patterns. Instructional procedures that force higher performance aircraft into inefficient flight maneuvers is detrimental to flying.
The more variations in departures and arrivals the better. This will serve to familiarize the student with identifiable ground points known to ATC. It also helps analysis of the reports of other aircraft and their relative importance. (More on this later) Failure to offer and discuss arrivals and departures severely limits the development of competency. The prelanding process should be a routine ground pre-flight instructional procedure. All of the foregoing is taught with the expectation that it will carry through to more complex aircraft.
In time, each pilot will develop personal preferences and standards for pattern procedures. The ideal is to give other pilots the maximum opportunity to see and hear about your arrival, entry, and plans. Being accurate in giving your position helps ATC and other pilots.
Most mid-air impacts occur in the pattern. How you arrive at pattern altitude is partially determined by your aircraft. Low wing aircraft are well advised to arrive at or slightly below pattern altitude. High wing aircraft see better when descending. If you fly a very wide pattern it is likely that some aircraft closer in may unintentionally cut you out on final. Fly the pattern so you are where you are supposed to be and where others will be looking for you.
Flying Tight airport Patterns
--More efficient use of aircraft and time.
--Large pattern in slow aircraft inconveniences others.
--Keeps you closer to airport in event of engine problem
--Nothing in a pattern requirement is carved in stone.
--Required ATC separation is 3000 feet between two aircraft on
same runway
--Use your base turns as airspeed change exercise
--Practice power-off landings.
Pattern
Diagram (Instruction)
The following diagram is a worthwhile exercise for a combined
student and instructor lesson. This is especially true for the
student who is learning at an uncontrolled airport with limited
approaches and departures. At a controlled single runway airport
all of the arrivals and departures would be possible in a calm-wind
situation. It is important for a student to be exposed to all
of the alternatives both as flight procedure and radio procedure.
Draw a diagram of an uncontrolled airport arrival at your closest such airport. Write in the radio calls you would make all pertinent points. Review with an instructor
The radio advisories (uncontrolled) and requests (controlled)
will vary for every arrival and departure. The 45-degree sight
lines have been extended inside the pattern to illustrate selection
of the 'numbers' as your entry aiming point for downwind entry.
This works very well when used on a 5000' runway. You get 1/2
mile to the numbers, another 1/2 mile downwind extension, a 1/2
mile base and a 1/2 mile final. By unwinding this you also get
the two-mile reporting point usually requested by ATC.
The same diagram depicted for a 2500' runway presents an optical
illusion that creates a very compact pattern that is most likely
to place the pilot too close and too high on the final approach.
Again, a relatively slight adjustment to the visual planning
will resolve the problem. You must visually pre-plan a wider
and larger pattern that on a downwind 45 entry will make the
turn to downwind not at midfield but at the departure end of
the runway. the general rule is to stay farther away in the pattern
that you think is required (about twice as far) and you will
be about right. Adjusting to airport size is most difficult for
those pilots who have never been subjected to the visual differences.
Diagram two similar runways that differ only in with and length.
One should be twice the size of the other;. Note how using the
same perspective can cause great differences in pattern size.
A flight-training program should provide the new student with opportunities to develop the needed pattern adjustment and orientation skills. Extensive pattern work at the home field is not the thing to do. Make flights to nearby airport for development of skills required in airport arrival, pattern entry and approach adjustments.
Traffic Watch
1. Avoid vicinity of VORs
2. Avoid gadgets in the cockpit
3. Do not rely on radar advisories
4. Do not rely on another pilot's position reports
5. Scan much more than just the pattern.
6. Use your lights
Seeing
The more contrast between plane and sky the easier an object
is to see.
Moving eyes are blind. You must scan in movements that can be
focused. It takes over twelve seconds to see and avoid an airplane.
Five of these seconds is just is seeing the problem. Four more
seconds are used to decide what to do. One second to get your
muscles to move. Two seconds to get the plane to move.
Closure rate of 360 knots
Here you are only 30 seconds from impact
You've used 12 seconds to move the plane
Your cushion is 18 second
Seeing What
You're Looking For
The pilot seeking a final stabilized approach to landing
should develop a program of constants in the airport pattern.
Power is reduced to 1500 rpm. The aircraft is trimmed for a pre-selected
airspeed for every leg. Flaps are applied in 10-degree increments
on each pattern leg according to pilot judgment of wind and pattern.
The use of a consistent size pattern including the planned application
of flaps at pre-selected points of the pattern allows the student
pilot to develop the necessary decision making judgment.
The day of just pointing the plane at the runway left with
the invention of flaps. The pattern and especially final is flown
at a constant power, airspeed, and glide angle. Once the constants
are set, the pilot is able to determine his relationship to the
landing zone. Finding this relationship visually is just as difficult
as finding the 'sweet spot' for level flight. With practice and
experience any changes in the visual space between the nose of
the aircraft and the end of the runway and any changes it its
trapezoidal shape will enable the pilot to determine if the approach
is high, low, or O.K. The constancy of flap/trim application
during landings produces repeatable results. The production of
repeatable results during approach, roundout and flare is what
produces good landings.
When the space between the nose of the plane and the end of the
runway is decreasing you are too high. This is NEVER adjusted
by lowering the nose with a resulting airspeed higher than normal
approach speed. Flaps may be added, power reduced, or airspeed
reduced to short field minimum. (As a last resort shallow S-turns
can be used if altitude and distance allow. Proceed very carefully
as to airspeed and bank.) These three basic options are the only
ones available to students.
When the
space between the aircraft nose and the runway seems to become
larger and flatten, the runway trapezoid lengthens. You are low.
Do not add a little power, add FULL power. Hold forward yoke
pressure, maintain approach airspeed until the nose of the aircraft
visually touches the runway. Now reduce to normal approach power
and proceed. (See material on the decelerating approach below)
The runway will retain a constant relationship to the nose of
the aircraft. Normally there will be about 100' of space between
the nose and the end of the runway. If the space decreases or
the nose visually touches the runway you are too high. When the
space increases or seems to flatten you are low. Appropriate
corrections are called for if high or low.
If high, flaps may be added, power reduced, or the nose raised to decrease airspeed. The last action, apparently contradictory should be explained and practiced. The best solution for being low is to apply maximum power for a duration sufficient to acquire the desired glide slope. This too should be practiced.
Runway Lights
The A/FD has information as to type of system at airports.
Alignment of Elements is an array of three unlighted plywood
panels in which the middle panel can be above, in line, or below
the two outer panels
VASI
If you have visual contact with the runway the FAA recommends
flying the VASI if it is available. If there is a visual descent
point (VDP),You can descend below the MDA (minimum descent altitude) if you have visual reference
as required by FAR 91.175(c)(3). You cannot descend below the
MDA before the VDP.
According to FAR 91.129 (d)(3) a flight into a VASI at a controlled airport with the tower open must remain at or above the glidepath until lower is required for landing. The rule applies only to a VASI and not to other glide slope light system. The rule applies only if the tower is operating.
The three-bar VASIs has two glide paths. The far two bars
are for large aircraft; the two near bars are for small planes.
Normal glide path is 3 degrees and upper glide path is 1/4 degree
higher. Some locations have 4.5-degree glide path to give obstacle
clearance. VASI is not part of instrument landing system. An
inoperative VASI does not affect IFR minimums. Obstacle clearance
up to 4 miles or less and 10 degrees to each side.
Tri-color VASI
Green is on glide path, white is above and amber/red when below.
PAPI
PAPI stands for precision approach path indicator. Four lights
to left of runway. 4 white for high; 2 white/two red for just
right, four red for low.
PLASI is a rarely used single light system where a single white light shows when on glide path and a red light when below. You may see a pulsing red and white light that increases frequency the more off the path you may be. Can be confused with newer aircraft tail beacons. (Was used for many years at Livermore before it had a tower.)
Short
Approach
The short approach is a pattern landing procedure that may
be used by the pilot by pilot request, ATC request at controlled
airports or when desired at uncontrolled airports. The purpose
may be practice, economy, traffic or just 'because'. In a normal
downwind pattern, when abeam the numbers C.H. is applied and
power is reduced to approach power. Hold heading and altitude
until the airspeed reaches the white arc. As soon as the airspeed
reaches the white arc an immediate turn to base is begun with
simultaneous application of full flaps. At approach speed the
path of the aircraft is adjusted to the threshold of the runway
by making the base leg angle toward the runway as required to
give alignment for final approach. For practice purposes it is
wise to use 1000' markers for the threshold.
Short-Short
Approach
This is not a recommended landing because it shock-cools
the engine. Downwind prelanding check. Abeam the numbers power
off. Hold altitude until white arc and put in full flaps. While
flaps are going down make turn to base. Fly 60 kts. Trim. May
need to fly direct to runway. Round out. Flare. Touchdown. Rollout.
Cleanup. 55 kts on short final for short field. Flaps up. Brakes.
Decelerating
Approach
Certain airports and aircraft lend themselves to long, flat
and low final approaches. Such an approach can lead to the "constantly
decelerating approach" due to elevator use or the 'behind
the power-curve approach' brought about by gradual increases
in power. The only 'correct' procedure for a perceived
low approach is full power applied to attain the normal approach
slope and airspeed. Any gradual application of power or yoke
adjustments will only make the aircraft go slower and slower
and down faster and faster. Refer back to the undershoot landing.
This approach is relatively common to new or airport unfamiliar pilots. When low they will add power. The nose rises and puts the runway where the pilot want it. What is not noticed is that the airspeed as dropped a couple of knots. If the airport is being flown at a best glide airspeed initially, the couple of knot airspeed decrease will result in an increased rate of descent. Once again the aircraft is low.
The
pilot again adds a bit of power that again causes the nose to rise so as to
give the appearance of being on glide path. Again, the pilot adds
power. This process can continue, especially at night, until the plane
is being flown with full power at a high angle of attack. The plane is
out of any power reserve and is unable to climb.
Flying speed can only be regained by lowering the nose and losing some
altitude. If ground proximity is a part of the problem, and it usually
is, an accident is inevitable.
The only cure to the situation is pilot
awareness that power, by itself, will decrease airspeed. There
is a dangerous lag in the loss of airspeed with the addition of small
amounts of power. The pilot needs to have had training and experience
recognition in adding full power while holding a constant airspeed to
re-acquire the proper glide path. Certainly the occasional low approach can
be salvaged by small additions of power just as an accomplished pilot may
salvage a poor landing. For the masses of the just average to below
average the only solution to being low on the approach is glide path is FULL
POWER WHILE HOLDING THE APPROACH SPEED and this takes
practice. .
Extended downwind
I fly at cruise speeds until abeam the numbers. When I reduce or takeoff power
abeam the numbers I maintain altitude to keep closer to the runway.
Any time I am #3 or higher to land I go to slow-flight to keep closer to the
runway.
At towered fields, when told to extend downwind, I may request a right/left
270 re-entry on base to keep closer to the runway.
All of those mentioning inability to reach the runway after power failure have
never mentioned their flap configuration. I have posted this advice in other
threads previously but it deserves repeating. In the pattern there will be
times when you will not be able to make a runway. At every point in the
pattern have a pre-planned engine-out option. Have a planned selection of
runways, taxiways, fields, or streets.
I do have a pre-solo simulated emergency that I have used with every student I
have taught. Twice, that I know of, the lesson has prevented an accident. The
lesson consists of an aircraft on final in full flap and l500rpm power. At
400' I will reduce the power to idle. The student has been coached to
immediately recognize that he will be unable to reach the runway unless he
takes immediate action.
No way to make the runway? Take off all the flaps while maintaining normal
approach speed. Aircraft will lose about 150' immediately and will then
establish a shallower glide path. Should land halfway down the runway. Try it,
you'll like it.
Why Patterns Are Different
Hello .(Question)
I am a student pilot with about 18 hours now and am flying a C152. My
primary instructor has about 30 years of experience and my backup instructor
is a graduate of UND and has about 6 years flying experience. Both are
commercial rated CFII's. The more experienced instructor recommends I hold
pattern altitude until I turn base while the younger CFI recommends I begin
descending abeam my touchdown point on my downwind. I tend to descend
differently, depending on who I am with. Both say to decrease power to about
1700 RPM and add 10 degrees of flaps when abeam the numbers. However, I find
it difficult to maintain 75-80 kts on downwind after I reduce the power and
add 10 degrees of flaps. I gradually sink while trying to maintain this
speed.
The older instructor had a student fail this part of his PTS checkride
because the FAA examiner said the student should have held the altitude
until turning base. The examiner said something about not giving away
altitude that may be needed if the engine quits.
John
John, (Answer)
Welcome to the world of conflicting requirements and flying in them. Local
agencies make the rules for airports within their jurisdiction. The rules
run all the way from none, to don't fly over this house, to don't turn
until crossing the railroad tracks, to no pattern turns below 600-feet, to
no straight-in arrivals, etc.
I taught a fellow from Switzerland. who had an airport pattern diagram of
his home field with the pattern curved where necessary to avoid certain
homes.
Be extra careful about changes in patterns at night. Even through controlled airports are uncontrolled when the tower closes, the left pattern standard may or may not exist. Oakland has a runway in common use that cannot be seen from the active tower at night. All clearances are conditional. O.K. to takeoff/land but we can't see where you are or what happens. Expect to fly right patterns
The airport at Napa has a VOR instrument approach with a procedure turn
published. However, due to some political influence this procedure turn is
no longer used because someone lives below it. Turn is at 2900' AGL.
Historically, all patterns were at 800'. Then when homes began to surround
airports they were moved up to 1000 or even 1200 feet. Neighbors on the
downwind legs of these patterns began to see the noise benefits of higher
patterns and had the local politicians write into the rules that the
downwind leg altitude 'should' be maintained until turning base. (Concord,
CA where I fly has such a local requirement) Concord also has noise sensors
that can match aircraft with tower tape times for identification.
Oakland and Hayward have different altitudes for different runways by
local regulation. This is the reason for the conflict in instruction and
instructors. ATC can have you 'violate' these regulations when they wish to
for a reason. My airport has at least seven noise sensors to determine which
aircraft makes too much noise. Some airports are even closed at night
because of noise. The pattern problem you are experiencing is all about
noise.
In my opinion, in order to minimize noise complaints is it better to stay
high. We are historically losing one airport a week in the U.S. Concord was
at one time the 9th busiest airport in the country. This week the County
will be having a preliminary meeting about making it an industrial park.
Gene
On Making 45-degree
Entries to Runways
I want to thank Dudley H. for drawing my attention to
the use of course instead of heading
Runway directions are courses, not headings. Common usage is a
technical error.
There is considerable repetition here but using a
compass rose or a manual E-6B makes it easier to see. Draw out the runway
directions, the leg directions and 45-outbounds as well as the 45-inbounds
until you really understand what is going on. Once you understand the
relationships airport arrivals will become easier.
Calm wind conditions.
Runway 36 Sum of digits (add numbers together = 9
Other end is 18 Sum of digits = 9
Runway 27 Sum of digits = 9
Other end is 9 = 9
Look at compass rose around a VOR
Basic Rule
All four numbers 90 degrees from another as in a + sign add to the
same number when you add the digits.
030-degrees = 3 add 90 degrees you get 120 sum of digits = 3 add 90 degrees
210 = 3, add 90 degrees is 300 and sum of digits = 3. Not very obvious on a
compass but easy on heading indicator.
If the runway of choice is 25...Runway 25 is considered as 250 degrees
magnetic. All runways are magnetic courses rounded to the nearer zero. The
beauty of their adding up means that you can make 90-degree turns to a
course just by knowing the sum of the digits, easier than adding or
subtracting 90. Every turn in the pattern in calm conditions will be a
90-degree turn. For runway 15 your takeoff course is 150 = 6; your right
crosswind turn is 240 = 6; your downwind turn is 330 = 6 and your final turn
is once again 150 = 6.
Just a week ago I took my pre-solo student up in a reduced visibility situation with scattered clouds. Until I pointed out the above use of the heading indicator he was having all kinds of difficulty locating the airport and keeping his pattern in order.
Discussion
Students and pilots often have difficulty making a 45-degree pattern
entry to an uncontrolled. airport. About three weeks ago with the same
presolo- student we were at an uncontrolled airport and set ourselves up for
a 45 entry to downwind. When we made our radio call as being on the 45 three
other aircraft responded all saying that they were also on the 45-degree
entry. Well they weren’t but we were. One was closer to a downwind;
another was on base entry and the third we never did find. Knowing how to
make a good 45-degree entry at an uncontrolled airport is a matter of life
and your death.
By over flying the numbers of the runway at right angle to the runway. At
the moment you are over the numbers make a 45-degree turn to the outbound
45-degree course. The heading indicator has a ^t the 45-degree points so no
figuring is required. However the sum of the 45-degree numbers will add
to the same sum of digits as do the 90-degree numbers except using three
digits with the last one a FIVE. Look at the heading indicator and you
will see what I mean. This over fly arrival should be twice pattern altitude
initially but descending to 500' above pattern altitude. This descent should
put you well outside the normal traffic pattern.
Extending further will increase safety margin from downwind traffic.
When you depart outbound from the numbers for an uncontrolled airport
entry, your new 45-degree inbound course will be at the bottom of your
heading indicator when outbound. I generally like to initiate my 90-degree
part of the reversal away from the airport. Doing this allows me more time
to adjust for any adverse wind effects during the 270. I teach using the
outbound 45 and the course reversals as a place and time to lose altitude so
as to enter the inbound 45 at pattern altitude.
Practicing The Course Reversal
Now comes time for the course reversal. This is NOT a 180-degree turn.
It is designed to put you right down a line going in the opposite direction.
The best way to practice this is over a VOR at about 2700' AGL and clear of
any Class C or B but only after walked through the process on the ground.
Figure out the wind direction and fly into the wind right over the VOR and
set the OBS to the direction you are flying according to Compass set Heading
Indicator. Fly for two minutes and begin your course reversal. You make all
turns at 30-degrree banks because that is the most stable bank you can make.
Always orally and visually clear your turns.
Before beginning the turn look to the bottom of your heading indicator and
NOTE the course you will need to be going the other direction. Make a
smooth 90-degree turn and then reverse the bank 30 degrees to the other
direction and level out on the course you NOTED above after turning 270
degrees.
That is a course reversal. BUT during the process of making the 270 you must reach up and reverse the OBS setting or you will get reverse sensing. If you started on 360 you must change the OBS to 180.
Knowing What You Are Doing:
In your flying toolkit you need several skills. You must understand
that there is a unique inter-relationship between all the numbers that are
90-degrees and 45-degrees from each other. Since runway directions are
always rounded to the nearer 10 degrees the runway number always drops the
final zero. Also any 45-degree angle from a runway course will always end
in 5. With this knowledge you then put the fact that the sum of the digits
are always equal and you can come up with the number you need
If your runway is 25 (250=7) and you fly across the numbers at right angles.
With the extended runway to your left you are heading 025=7 and with the
extended runway to your right you are heading 205=7. For the right outbound
45 you add 45-degrees and get 295 = 7. You keep adding until you get a
single digit. For the left outbound you subtract 45 and get 205. When you
know you are going to an airport that may require a 45 entry, work it out
before you get in the plane. Draw your own compass rose and see how it
works. Let me know
if you have difficulty.
Walking through the 45-entry with a Course Reversal and radio calls.
Draw a runway on pavement with a number and walk several times
through the course reversal and pattern procedure. Then do it again with the
radio work. Even if the runway changes, doing this will help.
With radio and alone at uncontrolled airports you initially report your position and altitude some place or distance and altitude relative to the airport. This is the initial call-up. At the same time you can state your intentions are to over-fly at a safe altitude above pattern altitude. Once over the field and having circled or otherwise determined the active runway you again state your position, altitude and intentions. A call might say, "Podunk traffic Cessna 1234 over field at 2600 planing right 45 for 25 (runway number) Podunk."
You over-fly the numbers and turn left 45-degrees to make the outbound 45 while descending well beyond the downwind leg. You report being on the outbound leg as, "Podunk traffic Cessna 1234 outbound right-45 for 25. After noting the course of the inbound at the bottom of your HI, you initiate a course reversal to the right for 90-degrees and then reverse the bank and turn 270-degrees back to the inbound 45 while descending to pattern altitude. Again you report, Podunk traffic Cessna 1234 on right 45.for 25 Podunk.
On turning downwind, base and final, you report as before always giving your position, runway number along with Podunk as first and last words of call. On final you should include your intentions as far as landing etc. On full stop landings it is proper to report when clear of the runway.
Diagramming the 45-Entry
I drew out a runway with 25 and 7 as the runway numbers at each end.
Also drew in the downwind courses for both left and right sides of the
runway. Then I drew in the four possible 45-degree entries. The 45-entry is
aimed at the landing numbers but the turn to downwind occurs at mid-field.
When I turned right to the downwind the course number increased by
45-degrees. When I turned left to the downwind the course number decreased
by 45 degrees. When you are entering a 45 to a right downwind your turn will
be to the LEFT. Numbers will decrease by 45. When you are entering a 45 to
the left downwind your first turn will be to the RIGHT. Numbers will
increase by 45. All of the related number to the runways will always have
the same Sum of the Digits. SEVEN
Conflicts of Arrivals and
Departures
There has been considerable internet discussion on airport
departures so I have decided to offer my cents, since, sense to the mix.
The safety of the departure is wired to the safety of the arrival. I have
found that large proportion of experienced pilots make their 45-degree airport
entries aimed at the midfield turning point rather than at the landing runway
numbers. Doing this greatly reduces the lateral clearance between arrival and
departing aircraft. Even more so if runway is short. At short runways the
downwind turn is made at the departure end of the runway but the aiming point is
still the landing numbers.
A couple of simple diagrams can illustrate the point. My computer refuses
to put the diagrams up..
Uncontrolled Airport Arrivals
A second aspect of uncontrolled airport arrivals involves how to make
the 45-degree arrival. Here is the way I teach it in combination with the radio
procedures.
On knowing I am approaching the airport about 10-miles out I get the one-minute weather from the AWOS/or ASOS and plan my 45-entry accordingly. Without the wind or runway we communicate initially with the UNICOM for an advisory and then to airport traffic giving our arrival plans. Without wind or runway information we indicate that we will over fly the airport at slightly above twice pattern altitude. Throughout the arrival we inform traffic of every significant change in direction and altitude.
While circling we determine the active runway and pattern direction. The
direction of the circle initially will be left turns but if traffic pattern is
left traffic we will reverse into right turns for reasons that follow.
Once we have circled to determine the landing information we adjust the circle
so that we will over fly the landing runway number at a right angle to the
runway direction. In left turns the runway will be to our left and we will
immediately make a left 45-degree turn to an appropriate heading or landmark.
Were we to be making left traffic in the selected pattern then we will circle
to the right and over fly the numbers of the runway at a right angle with the
runway to our right. At the numbers we make a right 45 outbound 45 while
initiating a descent that will over fly the downwind pattern altitude by 500’
or more. When well clear of the pattern we will continue our descent. Now it is
important that we note the reciprocal of our bound course since it will be our
inbound course after completing the course reversal.
I prefer to make the first part of the course reversal as a 90-degree constant
angle bank into the wind and making the 270 part second back to my inbound 45 to
the downwind. The beauty of the course reversal is that in no wind conditions
and a constant angle of bank it works perfectly. (The FAA now accepts it as an
alternate procedure for IFR holding pattern entry.) On completion of the course
reversal you should be aimed at the landing runway numbers and at pattern
altitude.
The following crude illustrations are for both right and left traffic patterns. They may be crude but my computer refuses to let me post them. You should be able to draw the diagrams using the instructions.
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