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Maintenance and Paperwork
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Know the Airplane; ..Aerobatics; ...GA Aircraft in Icing Conditions; ...Aircraft Papers; Weight and Balance; Aircraft Loading; ...Baggage Security; ...Airworthiness; ...Airworthiness and Maintenance; Who's to Blame?; ...Supplemental Type; ...Airworthiness Responsibility; Records and Current Inspections; ...Aircraft Parts; ...Is it Airworthy?; .Performance Modification; ..Insurance; ...Changing Type Certificates; ...Permanent Records; ...Aircraft and Engine Logbooks; ...Inspections; No-nos of Annual Inspections; Operating without a (MEL) (Repeated material also covered in PTS); ...MEL Decision Sequence:; ...Inoperative Equipment; ...Pilot Maintenance; ...Most Dangerous Thing in Aviation; Pilot/Owner Maintenance; ...Inspections; ...Airworthiness Directives (ADs); ...Permanent; ...Service Difficulty Reports (SDRs); ...Service Bulletin; ...Major Maintenance; ...Overhauls vs Zero Time; ...Fault; ...Airworthiness Directive; ...Maintenance; ...WD-40; ...Maintenance Shakedown; Things That go Wrong; NTSB Reporting; ...Performance; Cleaning Materials; Refueling and Static Electricity; Maintenance Revisited; Preventative Maintenance; Changing a Nose Tire; Finding Fouled Plug; Spark Plug Replacement Kit; About the Annual Inspection; Annual Inspection by Checklist Phases; AD Compliance; ...Riveting in on Riveting; ...An FAA Ramp Inspection Checklist; ...FAR Part 39 Airworthiness Directives...Way to Weigh; ...Aircraft Maintenance
Once you start flying a particular aircraft you should start learning how it differs from the information in the POH. The POH data is for a new aircraft with the best of pilots the manufacturer could obtain. Begin by operating with the book figures.
--Use radar or a GPS to obtain performance figures at 75% power.
--Have the aircraft refueled after each flight and develop a consumption table for the flying you do.
--Develop your own tool kit, as things need fixing.
--Learn what is normal for this particular plane so you can become sensitive to such things as carburetor ice, an door ajar, a pending brake problem, control freedom, trim settings, seat problems, etc.
Reading FAR 91.9 says the aircraft must have an AFM/POH but FAR 21.5 says this is only required only for aircraft certified after 1979. All prior to 1979 aircraft may fly legally with placards. The only way to find out if an aircraft is required to have an approved manual aboard is to check the type certificate data sheet. This sheet is available at the local Flight Standards Office.
Aircraft structure has progressed from wood and wire to mild steel and chrome-moly steel. Along came aluminum alloyed with copper for strength, magnesium for resistance to corrosion and manganese for workability. The alloy can be clad with other metals to acquire any desirable quality. Pure aluminum is almost proof against corrosion. Titanium melts at 2700 degrees and is 60% heavier than aluminum while 50% lighter than stainless steel. Magnesium, with the highest strength to weight ratio of all aircraft metals, is 2/3 the weight of aluminum. Magnesium's drawback is that it burns explosively once reaching 1200 degrees. Synthetic composites and boron fibers are the present new kid on the block. Any rivet used must be compatible with the metals being joined.
The basic criteria used by the FAA for aircraft components of a critical nature is one failure in a billion flight hours. This high standard today is unreasonable when applied to aircraft of an older era with most parts nowhere close to this modern standard. The FAA is changing to allow a failure to flight hours at least equal to the system being replaced. Electronic ignitions will be replacing magnetos.
The aircraft is designed to crumple every place but the cockpit. Where conditions do not permit an obstacle free landing, you should select obstacles that will absorb impact. With secure and tight belts you will not bounce into the parts of the cockpit. You are far more likely to be injured by beating yourself against the inside of the airplane than in any other way. Some form of engine failure causes 1/4 of all accidents. Mechanical failure is the form least likely to occur. Running out of fuel is most likely.
Performing maneuvers that the plane is not certified for is foolish and unprofessional. In aerobatics a little knowledge is dangerous. Aircraft safety margins exist but they are not large and usually apply to normal operations. Failure is apt to occur due to long-term fatigue or corrosion where the failure margins have been lowered. Even minor excess stress on an aircraft is accumulative. An aircraft that has been over stressed is just waiting for the next pilot to make it come apart. Every pilot flying a previously flown plane is subject to whatever has been done to the airplane before.
The shape of the structure determines much of the strength of an airplane. The slightest change in shape can greatly reduce aircraft structural strength. Proof of this can be demonstrated by using a soft drink can. A can can hold your weight if the shape is undamaged. A pinhole in the side can cause a can that once held your weight to collapse. When even a minor aspect of aircraft shape is changed the strength of that structure, it is no longer as certified.
It is the responsibility of every pilot to operate the aircraft in compliance with the restrictions and limits of the manufacturer's POH and placards. This requirement is part of the FARs Part 91.9.
in Icing Conditions
FAR 91.9 requires obeying operating limitations of POH and placards. If operation in icing condition is prohibited then you cannot fly into known or forecast icing.
No small aircraft built before 1979 needs a POH. Every younger plane must have an FAA Airplane Flight Manual (AFM) that is only issued for a specific airplane unlike the POH, which is for a large group of similar aircraft. If the POH has weight and balance data them it too, like the AFM must be aboard the aircraft. It is always a good idea to make periodic reviews of the manual information and recommendations for normal and emergency operations.
When is a new weight-balance Required?
Negligible weight for an aircraft whose empty weight is less than 5,000 pounds is considered to be any change of 1 pound or less. For an aircraft with an empty weight between 5,000 and 50,000 pounds, items weighing 2 pounds or less are negligible
( http://www.aopa.org/members/pic/ac/maintenance.html ).
--A plane with weight at the rear limit of the envelope becomes
unstable and will have difficulty bringing the nose down at very
slow speeds such as a stall.
--With the weight too far forward the plane becomes so stable that you might not be able to bring the nose up to land.
The range for an a particular aircraft is shown in the POH charts and is supplemented by the actual weight and balance papers required aboard the aircraft. Finding that the weight is in that range of the envelope is the "balance" part of the weight and balance problem.
Aircraft balance determines where the weight (fuel, people, baggage) is in the envelope. Each bit of weight is referenced to a station. Every station has an distance measured from the aircraft's datum point. By multiplying this distance by the weight placed at each station you obtain a figures called 'moment'. You add all the moments together including that of the aircraft and divide it by the total weight of the loaded airplane. In the weight and balance papers is a chart that you can use to determine if you are within balance limits. An aircraft can be under gross weight, but out of balance. Also, a plane can begin a flight within the envelope but be out of the envelope as fuel is used.
The balance part of the aircraft weight-balance applies to the balance distribution of aircraft weight. The aircraft must balance somewhere within the balance range and balance equation is as important as the weight of the flight envelope's longitudinal axis. Where it balances is called the called the center of gravity. By aircraft design there are limits to the ability of the center of gravity to move forward and backward. these limits are determined by the control effectiveness in maintaining pitch control at the slow-extremes of airspeed.
--Over weight and out of center of gravity limits makes an
--General aviation's aircraft may not be individually weighed. Manufacturers fleet weight may be used.
--New installations require a new computation and 'superceded with date and certification of mechanic.
--AC120-27C makes change of less than one-half of one-percent of weight or C.G. reweighing exempt. (Thats .005 of gross weigh or 1/2 pound per 1000 poundst)
--Weight and balance records must (should) be part of the pre-purchase records.
--Each new weight will probably give a new C.G. location and range.
--Different manufacturers use different datum points.
--Gasoline weighs differently for different temperatures. At higher temperatures gasoline weighs less.
--Only at -7 Celsius does gas weigh 6-pounds per gallon.
Average G. A. load is 1.7 people. Single engine aircraft are required to have a stall speed below 61 knots. A G.A. aircraft must be able to climb at gross with full flaps Some C-172s have difficulty on a warm day or at altitude. In later models of Cessnas the limit of 30-degrees flap extension allowed certification 100-pounds heaver than at 40-degrees flaps.
--The actual weight of baggage limit is made low because of the potential G-loads possible on aircraft.
--A significant increase in G-force could damage the structure or cause an aft center of gravity.
--The security becomes important especially if moving baggage changes the C. G. of the aircraft.
--Never put something in the back of the aircraft that you may be needing in flight.
FAR 91.7 says the pilot determines the airworthiness of an aircraft. The AROW papers must be aboard and displayed in the aircraft. If used for instruction the 100-hour inspections must be made. Annual inspections must be made. Inoperative equipment cannot be required by aircraft type certificate or Airworthiness Directive. Equipment not working must not be required for the type of flight to be made and must be placarded as inoperative by a certified mechanic. Proof of airworthiness requires proper documentation of required inspections and compliance with all applicable airworthiness directives. Combine all of the above with a conscientious preflight and you have an airworthy aircraft in which to sit. Technical compliance does not mean safe compliance. Don't start the engine until you have all available information related to the movement or flight. Read FAR 91.213. This is an emotional area for pilots because so little is known about it.
On manufacture, a plane is given an airworthiness certificate that says the plane was made according to approved type design that met safety requirements. This is attained when the required and proper components are installed and they are consistent with the drawings, specifications, and other data that are part of the type certificate. An airworthiness certificate is valid only if required maintenance has been performed according to FARs 21, 43, and 91.
When inspected in accordance with FAR 43.11(a)(4) says that the AI doing the inspection must certify that a given type of inspection was made and that the aircraft was determined to be airworthy. Section (a)(5) of this FAR gives all the reasons for which an aircraft may not pass the inspection.
The largest single expense in a year will be the 'annual inspection. In this inspection any previous discrepancies are apt to be discovered. The inspection standards are found in FAR Part 43 and the manufactures service manuals. Anticipate that the annual inspection will include a significant number of unexpected expensive repairs. Only be anticipating the worst can you be pleasantly surprised by the cost of an annual inspection.
Regardless of the type and extent of any damage, the determination of airworthiness requires that an A & P render a judgment. Whether what has happened is a major or minor defect depends on the effect on airworthiness. A major problem affects weight, balance, strength, performance, operation, or flight characteristics. Major repairs means strengthening, reinforcing, splicing, and re-making primary structure. Replacement occurs by fabrication using riveting or welding. Major repairs must be logged as approved by a Certificated Repair Station or an A & P with an inspection authorization. Any other repair is minor and may be signed off by an A & P.
Any fault with the aircraft paperwork is an indirect the responsibility of the mechanic. The total responsibility rests with the owner/operator to see that not only is the work done but that the mechanic provides the required paperwork. You are required to explain all existing or non-existing maintenance entries. All entries have date, type of work done, hours on airframe and engine and a signature followed by license number. Major repairs must have a 337 Form signed by an AI.
An aircraft with missing paperwork is not airworthy. Lost books can be reconstructed by billing records. The only way to know if a maintenance problem has been properly repaired is the check the maintenance log books. A maintenance entry is like a brief picture of work done. A mechanics signature is valid for the moment of time when it was written. A day later the signature may no longer be valid. The paperwork shows the last annual inspection, and 100-hour if required.
An Airworthiness Directive is an FAA warning that certain
maintenance work is required on a specific aircraft production
or part series. Some ADs are only one time, some are recurring
at certain hourly flight times. IF an AD is not complied with
the annual is no longer valid. The maintenance logs are the only
place you can know of AD compliance. The pilot is, according
to FAR 91.7 responsible to determine the airworthiness of the
aircraft. It is relatively unusual for a pilot who flies a rental
or club aircraft to have access to the logbooks. Much flying
is done on faith.
Who's to Blame?
–Vicarious liability: You can be held liable to the victim of another person’s action.
–Employers are liable for the negligent acts of employees.
--Responsibility, accountability and liability involve what was done, what was not done by other than the pilot.
--You can be sued for liability even though you are not directly involved.
--Being a Good Samaritan with advice can make you liable
The FAA has set up a complex division of responsibility that allows no one and everyone to be accountable. Primary responsibility is said to rest on the owner operator. (91.403 and 405) The owner operator must ensure the compliance of all required inspections and airworthiness directives.
The one that does the maintenance is responsible for the airworthiness (43.13) this means that at the moment the work is completed, the aircraft is signed off by the mechanic with his certificate as being in NEW condition. The mechanic is responsible only for the work done or scheduled work not done.
The pilot in command of the aircraft is required to perform the preflight and determine the airworthiness of the aircraft prior to flight. In addition, he must ensure that all airworthiness directives have been completed and required maintenance has been completed and signed into the maintenance logbooks.
Anyone who reads the FAA double-speak of these requirements sees clearly that the FAA 'shared' responsibility is not so much shared as placed totally upon each leg of the triad. The FAA has shown a penchant for not very considered selection of one leg or another. There is no provision in the regulations for any sharing. Interestingly, when the courts get involved a fourth leg is created and often found responsible...the FAA.
Many aircraft are modified by a STC (Supplemental Type Certificate) which may require different than standard parts. Both the pilot and mechanics must be made aware of any STC and its requirements. Larger engines with higher fuel consumption are often installed with no change in fuel capacity and no entry into the Pilot Operating Handbook (POH). The right to use auto gas is another STC. The installation of a belly drain in a C-150/2 requires an STC.
The FAA does not require that the POH be modified to show changes in fuel required by a larger engine. Accidents cause FARs. Have an accident and create an FAR to cover the problem. If the aircraft can meet the original POH performance figures no changes in those figures are required even though they may be considerably different than actual performance.
Unauthorized changes can affect the safe operation of an aircraft.
A fire extinguisher mounted under a seat in the aircraft can
affect collapse design parameters. Simple modifications to electrical
systems can cause system failure. Wheel fairing can affect performance
and flight performance. The balance envelope usually has a small
window that can be drastically affected by movement of a small
weight for a long distance.
A major change affects strength, weight, balance, performance, structure, operation, flight characteristics, or airworthiness. These effects are most likely to occur when changes are made by other than standard practices. The safest procedure for changes is to contact the FAA Flight Standards District Office before starting.
Airworthiness is a shared responsibility between the owner, mechanic, pilot, and the maintenance and fueling organizations known as FBOs. The pilot is responsible for airworthiness from immediately before the aircraft is entered for flight until it is tied down. The pilot should make a comprehensive review of all the aircraft's paper work in addition to a thorough preflight. The mechanic's responsibility depends of whether an inspection or maintenance was done. For inspections, the mechanic's responsibility ends on completion of the logbook entries. The aircraft is airworthy at that moment. However, the same mechanic is responsible for any repair or work done on the aircraft back to the original airworthiness certificate until the next year's annual inspection. As owner/operator you are primarily responsible for airworthiness including the accuracy and completeness of all logbook entries.
The "Equipment List". That's a list that starts from the manufacturer and simply lists equipment installed on the airplane when it was manufactured. It is supposed to be updated each time someone adds or removes equipment and usually includes weight and balance info. Sometimes it will list "required equipment" which simply is an extension of equipment required by FAR 23 for certification and FAR 91 for operation. This list has NOTHING to do with an MEL!
A Minimum Equipment List is issued by the FAA to the OPERATOR of the airplane. In order to use an MEL you also need a letter from the FAA authorizing the use of the MEL for that make, model, serial airplane. The MEL and the letter form a Supplemental Type Certificate for the airplane, allowing the airplane to operate with certain pieces of equipment inoperative.
If you don't have an approved MEL for the airplane you are operating, you can only operate with inop pieces of equipment in accordance with FAR 91.213 (d).
and Current Inspections.
1. 100-hour inspections for instructional aircraft are required.
2. Corrections of any discrepancies found in previous flights are required.
3. The status of airworthiness directives (Ads) must be in the logs.
4. Any deferred maintenance must be placarded according to FAR 91.213(d).
5. A current weight and balance must be in the aircraft.
6. A current equipment list must be available if required.
7. The ELT battery expiration date must be both on the ELT and in the logs.
8. The Biannual test of transponder must be logged.
9. The biannual test of altimeter and static system (IFR) must be logged.
10. Any work done under FAA Form 337 must be logged.
11. If the type certificate data sheet indicates the existence of an approved flight Manual then that manual must be in the aircraft.
--91.403 ...the owner or operator of an aircraft is primarily responsible for maintaining that aircraft in an airworthy condition and for ensuring that maintenance personnel make appropriate entries in the aircraft maintenance records indicating the aircraft has been approved for return to service. It is the responsibility of the owner and operator to have maintenance performed which may be required between scheduled inspections.
--91.7 "...the pilot in command of a civil aircraft is responsible for determining whether that aircraft is ready for safe flight." Pilots must take reasonable care to find that an aircraft is airworthy and safe for flight.
-- Aircraft must (1) meet the requirements of its type certificate and (2) be in condition for safe operation. The type certificate verifies the design of the aircraft.
--FAR 91.7 (b) makes the pilot responsible for determining if a plane is safe to fly. Being safe to fly does not mean that the aircraft is airworthy. The completion of required maintenance and proper endorsement of the aircraft logbooks determine airworthiness. FAR 91.405(b) makes mandatory the completion of the logbooks. An airplane that is safe to fly but not airworthy can only be flown with a ferry permit. A certified mechanic before issuance of the ferry permit must placard any inoperative equipment on the aircraft as inoperative, disabled and noted in the logbooks.
--Violations of the safe to fly Vs airworthiness are discovered when the accident occurs. Then 91.405(b) regarding the logbooks kicks in but only after FAR 91.407 which requires completion of the work is satisfied. No matter who does the work, owner, pilot, or mechanic the 91.407 'return to service' endorsement is required. No matter what happens or who it happens to, the FAA gets to second-guess the process. Inadvertence, ignorance, or incompetence will not cover your butt.
--Proof of airworthiness requires written proof of required inspections and compliance with airworthiness directives knows as ADs. "Terms and conditions" of the airworthiness certificate requires that all maintenance and changes are performed according to FAR Parts 43 and 91. FAR 45.11 requires an external data information plate be on the aircraft, usually in the tail section.
--Maintenance must give a detailed description of the work performed, date of completion, signature, certificate number, and kind of certificate of the person approving aircraft's return to service. Even if the work is done, do not fly the plane until assured (Seeing for yourself) that the logbooks have proper entries and signatures.
--Records must show total operating time, time on limited life parts, time since overhaul, current inspection status, airworthiness directive compliance and any FAA Form 337's of major alternations or repairs. The parts and materials businesses must operate in such a way that expense is not and should not be the primary concern of the pilot or owner. Safety is. Where a maintenance problem exists, a passive approach is not going to solve the problem. A responsible person of the organization must take both liability and responsibility for what has occurred and provide the solution. Supervision of fueling is a most common source of difficulty.
The FARs require that all aircraft parts have some type of verifiable FAA approval. Even upholstery and belts require that they be fire resistant and of tested strength. The use of unapproved parts is a hazard. The fact that a part functions and looks good is not sufficient. Not only must the part be identifiable it must also be recorded into the aircraft maintenance records.
An approved part may be from the original manufacturer, approved under a Parts Manufacturers Approval (PMA), approved as a Supplemental Type Certificate (STC), approved by a Technical Standard Order (TSO) or approved by an FAA Field Approval (Form 337). Each part must carry a serial number and proper documentation. However approved, the part must also meet installation standards.
Material failure in metal parts occurs far less often than in rubber or plastics. Often replacement parts of rubber and metal in 1998 are far superior to those of 1978. Resistance to fuel, oxidation, and wear have been built into the newly approved parts. Stainless exhaust pipes are expensive but far more resistant than original equipment.
Is it Airworthy?
As students, pilots, renters and owners using aircraft we function at pilots in command. Every time we prepare an aircraft for flight we must preflight with a mental attitude directed toward the requirements of an annual inspection. When we fly we must be thinking of all the possible facets of aircraft performance. This might just be in terms of fuel and oil consumption. Unusual rattles, squeaks, movement, sticking or discrepancy.
The aircraft maintenance industry, in conjunction with the FAA, has accumulated a body of established criteria regarding what determines the airworthiness of aircraft. The criteria are precise in terms of aircraft design, aeronautical engineering, manufacturing standards and operational experience.
Not all discrepancies fit into the criteria box. There is some slack for the creative technician to interpret precise information that will allow detection and correction of a discrepancy. Practically all aircraft systems have gauges, dials and various types of indicators that are capable of giving notice of system malfunctions. An aircraft with a known discrepancy that cannot be set aside by placarding, removal, fixing or FAR is unairworthy.
The problem in knowing airworthiness lies in the need for specificity where the complaining pilots are unable to put the problem into words. The average pilot has a fear of being wrong about bringing up a discrepancy that affects the airworthiness of an aircraft. Another fear is that the availability and cost of flying may be affected by a reported discrepancy. Should a pilot hedge in the depiction of a problem it means that the situation is not fully identified.
Troubleshooting a discrepancy can be straightforward with detection; removal and replacement taking place. Trouble-shooting can be very complex for detection and diagnosis of discrepancies that are intermittent. Speculative repair work may mean that an aircraft is being sent out to fly while not proven airworthy. The type of discrepancy determines the appropriateness of the flight check. Proper maintenance steps cannot be taken until appropriate measures are taken to first fully identify and then fix discrepancies.
The problem that exists in the air often cannot be duplicated on the ground or on the workbench. This means that an existing discrepancy exists uncorrected.
The endemic problem in aircraft airworthiness has to do with the inability of the average pilot to clearly and succinctly put the problem into words. The information provided by the pilot to the maintenance people is difficult to interpret. A pilot who fully understands the aircraft systems, instrumentation and can use maintenance terminology to describe and explain a discrepancy is a fully rounded pilot. This means the supplied information is direct and descriptive. Otherwise, maintenance personnel must draw on past experience, imagination and luck to interpret a three-word squawk.
Therein lies a major cost in flying. The mechanic is obliged to spend maintenance time trying to recreate a poorly presented discrepancy. His efforts often indicate that since the problem does not exist on the ground, any on the ground maintenance fix is only speculative. The aircraft now sits in a sea of uncertainty. It is grounded, in need of a flight test. While an operational flight may be used to make an airworthiness check, it should not because of the uncertainty involved. Pilots should make unambiguous statements that insure grounding of an aircraft. It takes such positive statements to insure that positive actions are taken to identify discrepancies. It is pure negligence to fail to ground an aircraft by passing the responsibility off to the next user. Would you want it done to you?
1. Annual, 100 hour, or progressive inspection
2. Any discrepancy corrected found in preflight
3. AD status current and in compliance
4. FAR 91.213 inoperative items placarded and recorded
5. Weight and Balance papers
6. Equipment list (see manual)
7. ELT expiration
8. Biannual on transponder
9. Biannual on altimeter(IFR)
10. FAA Form 337's
Any modified aircraft must still meet FAA performance requirements in climb. A modification is usually more capable than advertised but requires more flaps than as certified. FAA approval does not say the change works, only that it is airworthy and within FAA performance guidelines.
A different propeller means that the speed of the aircraft for maximum engine performance will be moved slightly. Propeller pitch is selected to meet the FAA climb requirement and engine ability. A fixed pitch propeller at one specific point is more efficient than its constant speed cousin.
Modification of the wing tips are usually artificial ways of aerodymatically making the wing longer. Any device that reduces wing tip vortex effects does this. Any improvement in climb and takeoff will cause an unintended degrade in aileron effectiveness. Changes, such as tip plates, must be large to have a noticeable effect. Wing farings and gap seals are capable of giving some drag reduction with improved speed. The benefits become obvious only on long flights. I frequently fly in a C-182RG that is so equipped. ATC always calls us a Centurion.
A standard airworthiness certificate must be in full force and effect for insurance to be valid. If the FAA grants a waiver for a ferry flight the insurance company must be informed. Compliance with the FARs may not satisfy the insurance company.
Approved changes to an FAA Type Certificate may be:
Supplemental Type Certificates (STCs)
FAA Field Approvals (FAA Form 337)
Airworthiness Directives (FAR 39)
--Total time on airframe, engine, propeller, since last overhaul of items required to be overhauled.
--Status of life-limited parts, inspections, airworthiness directives.
--Copies of all FAA Form 337s with duplicate to FAA in OKC
--IFR records on pitot/static system, altimeter, transponder, encoder and VORs.
Logbooks, both aircraft and engine, must abide by FARs mostly Part 91 that require the logbooks follow the aircraft or engine.
FAR 43 covers who makes entries and the work that require entries. Everything must be entered into the logbooks. Major changes must be on Form 337. Major means anything that would appreciably affect weight, balance, structural strength, performance, power plant operation, flight characteristics or other factors of airworthiness. All work must be done according to accepted practices. The mechanic makes decisions and choices about maintenance just as a pilot does about flying.
Logbooks are a chronological history of the aircraft and engine. Breaks in time imply either storage or accidents. ADs are written on an aircraft and all its components. On engines there is no definition of an overhaul. Replacements may be new, used or original. Good records are hard come by.
Logbooks that are legal may not be helpful. Aircraft should have a master reference sheet to keep track of what was done- when. Tachometer time is correct only at 2400 rpm. Hobbes time reads clock time regardless of engine speed. A separate sheet of airworthiness directives should be present. Repetitive ADs are in separate column and must be there unless replaced by installation of newer components. Log Monthly VOR checks. Get computer generated forms to keep a better record.
Does not change prior history. Time is added as "since overhaul". Work by FAA licensee.
Time in service begins anew. Rebuild must be by FAA approved depot.
Type, description, date, total time, signature, certificate type and number; approval or disapproval for return to service
100 hour, minor alterations. A & P sign off required
Annual or progressive, major alteration AI sign off is required assuring compliance with ADs.
Not in FARs but require A & P signoff
of Annual Inspections
--Getting a cheap inspection
--Leaving discrepancies uncorrected
--Excessive flight hours between inspections
--Inattention to system performance
(Repeated material also covered in PTS Page 2.25)
Operating without a MEL
Minimum Equipment List
Most older aircraft have been certified without a MEL. Everything operational when the aircraft was certified must be operational for flight--including the cigarette lighter and tire pressure.
Without an MEL any inoperative item must be removed or deactivated and then placarded. A certificated mechanic must do the work, adjust the weight and balance, complete FAA Form 337 and approve for return to service
The pilot recognizes inoperative instruments or equipment
Do MEL or kinds of operations list require the item?
If "yes" aircraft is unairworthy!
If "no" 91.205, 91.213(d)(2)(ii)
Is the inoperative item required for this flight?
If "yes" aircraft is unairworthy!
In "no" 91.213(d)(2)(ii)
Is the item required by airworthiness directive (AD)?
If "yes" the aircraft is unairworthy
If "no" 39, 91.213(d)(2)(iv)
Is the item requires by FAR 91.107, 91.171, 91.185, 91.205, 91.207, 91.209 etc 91.213(d)(2)(ii)
If "yes" the aircraft is unairworthy
The item must be removed or deactivated and placarded inoperative 91.213(a)(3)(i), 91.213(a)(3)(ii)
Pilot must determine that the item does not constitute a hazard under the conditions of the flight. Pilot may perform work that comes under preventive maintenance. Item: Under the strictest interpretation of the FARs, it is almost impossible to fly a legal, airworthy aircraft.
FAR 91.213 is distinct from FAR 91.205 which just lists what is required for specific operations. 91.213 says you can't fly with inoperative instruments or equipment. Without an MEL, the alternative is in subsection (d), which requires a placard, plus deactivation or removal. Subsection (d) places total responsibility on the pilot.
1. The pilot must determine hazard potential, if any.
2. Determination may be made by certified mechanics.
3. Owner/operator must confirm if required for selected flight operation.
4. Refer to POH for selected flight operation.
5. If not required, deactivate and placard or remove by certified maintenance person who must make required placard and logbook entries.
6. Inoperative placard must be replaced at each required inspection.
Reasonable minds have protected G.A. pilots from the unreasonable application of 91.213, until now. This FAR states that no person may takeoff an aircraft with inoperative instruments of equipment. That can mean any instrument or any piece of equipment. FAR 91.213(d) allows placarding along with deactivation or removal of the inoperative component. A certified mechanic who has determined that the action does not constitute a hazard to the operation of the aircraft must do this. The mechanic must do the required placarding and make an entry into the aircraft maintenance records.
The equipment list is portion of the certification papers. An annual inspection on an airplane, requires the mechanic to inspect the airplane to ensure that it is in compliance with the certification papers. The mechanic then signs off the inspection. This certifies that the aircraft conforms with the certification. The FAA also has a minimum equipment list that recent aircraft must have on certification This is a shorter list than on the certification papers. You cannot certify an airplane without having everything on that minimum equipment list in place and operational.
An inoperative instrument that is not required for certification must have a label or placard indicating that it is not operational. If the item is required for the flight, it is required to be operational, otherwise, the airplane is not airworthy. "Required" items are required. The aircraft was originally built and certified with those items. The aircraft is not in compliance without the required items..
There is a way for flying an airplane that is not otherwise
legal to fly. It is called a "ferry permit." The local
FiSDO will issue a temporary permit that is good for a good reason
for a specific flight. You usually have a week to make the flight.
Before the ferry permit is valid, the airplane has to be inspected
by a properly certified mechanic and a logbook entry made that
the airplane is airworthy. You should inform your insurance company of
the flight and reason.
Alternatively, if you can determine that the item is not part of the VFR-day type certification items prescribed in the airworthiness regulations in effect when the airplane was type certificated. This information might be found in the approved flight manual if one exists. An item must be on the required equipment list otherwise it can be legally removed. An inoperative item must not appear on any list for the flight intended. Next, the item must not be required by FAR 91.205 as part of an airworthiness Advisory Directive.
Preventive Maintenance that can be performed by a Private (or higher) pilot are those 33 items contained in FAR part 43, Appendix A, subparagraph (c). FAR section 43.3(g) says "The holder of a pilot certificate issued under Part 61 may perform preventive maintenance on any aircraft owned or operated by that pilot which is not used under Part 121, 127, 129, or 135."
In accordance with FAR section 43.7(f) A person holding at least a private pilot certificate may approve an aircraft for return to service after performing preventive maintenance under the provisions of Sec. 43.3(g).
In accordance with FAR section 43.9(a) the pilot must make
an entry in the maintenance record of that equipment containing
the following information:
(1) A description (or reference to data acceptable to the Administrator of work performed.
(2) The date of completion of the work performed.
(3) The name of the person performing the work if other than the person specified in paragraph (a)(4) of this section and
(4) The signature, certificate number, and kind of certificate held by the person approving the work. The signature constitutes the approval for return to service only for the work performed.
An A&P Mechanic does not have to sign off preventive maintenance performed by a pilot. The pilot can do that. The best way to reduce to hourly cost of flying is to fly more often. Frequent flying makes you more sensitive to the performance and maintenance anomalies that occur. The builder/owner of a homebuilt aircraft is the licensed mechanic for that aircraft.
Thing in Aviation
--"A pilot with a tool box." or "A politician with a good idea." FAR 43.7(f) says that a Part 61 pilot may do preventative maintenance on an aircraft used in Part 91 operations provided it does not involve complex assembly work. The pilot can approve for return to service after work under FAR 43.3(g) 29 items are listed. The complete index is in FAR Part 43, Appendix A. Preventative maintenance on one aircraft may not be allowable on another.
--FAR 91.7 makes the pilot responsible for the airworthiness of an aircraft to be flown. Assumption of this responsibility carries with it responsibility to become and remain knowledgeable about the aircraft and its systems. The owner/operator is responsible for the actual financing of the maintenance. A certified mechanic must inspect any work done and make required entries in the records of the aircraft. FAR 43.3(d) requires that the mechanic personally observe the work and be available while the job is in progress. However, the FAA gets to second-guess all actions by these parties if something occurs.
--Logbook entries must describe the work done, the date of completion, name of worker, a signature, and certificate number. This signoff is approval for return to service only for work done by the signer.
--The best care you can show toward your engine is to use it along with some good pilot procedures. A sitting engine will rust and corrode. Avoid descents with reduced power which may cause shock cooling; high rpm starts which fail to provide required initial lubrication; and, excessive leaning at high rpm which will burn exhaust valves.
--Simple or minor preservative operations and replacement of small standard parts not involving complex assembly operations. Spark plugs, light bulbs, tires, and batteries. This type of work does not require recording in the maintenance records or service logs. If any of this work is done under the supervision of a mechanic an appropriate record must be made in the aircraft records.
1. Remove, install, and repair tires.
2. Add oil/air to landing shock struts
3. Service wheel bearings.
4. Replace defective safety wiring or cotter keys.
5. Lubricate items not requiring disassembly.
6. Replenish hydraulic fluid.
7. Apply preservative/protective material to components.
8. Repair upholstery and decorative furnishings.
9. Make small simple repairs to fairings, nonstructural cover plates, and cowlings, or install small patches and reinforcements ....that don't change the item's contour.
10 Replace side windows, if not related to structure or operating system.
11. Replace safety belts.
12. Replace seats or seat parts with an approved part.
13. Trouble shoot and repair broken landing light circuits.
14. Replace wheels and skis where not change in weight and balance is involved.
15. Replace any cowling not requiring removal of propeller or controls.
16. Replace, clean, or gap spark plugs.
17. Replace any hose connection except hydraulic.
18. Replace prefabricated fuel lines.
19. Clean or replace fuel and oil strainers or filters.
20. Replace and service batteries.
21. Replace or adjust nonstructural standard fasteners.
22. Install approved anti-misfueling devices to reduce the diameter of fuel tank filler openings.
23. Remove, check, and replace magnetic chip detectors.
24. Perform inspection and maintenance tasks prescribed and specifically identified as preventive maintenance in a primary category aircraft type certificate or supplemental type certificate.
25. Remove and replace self-contained, front instrument-panel-mounted navigation and communication devices in tray-mounted connectors.
26. Update self-contained, front instrument-panel-mounted navigational software databases.
--Pilots can perform preventive maintenance on aircraft operated under Part 91 of the FARs.
--Preventive maintenance is simple preservation and replacement of standard parts without complex assembly.
--Appendix A of Part 43 list the 32 preventive maintenance things a pilot may perform.
--FAR 43.9 requires logbook entries consisting of:
--Date of completion
--Description of work
--Data used to perform work
--Signature and certificate number
--Signature and certificate number is an "approval for return to service statement" for work performed.
--Performance standard must:
--Use method found in manufacturer's manuals and instructions
--Use tools required to do work in accordance with industry standards
--Use special tools as required
--Quality and work must be equal to original
-- A false entry violates FAR 43.12
The main difference between a 100-hour inspection and annual inspection is that the airframe and power plant mechanic can sign off the 100 hour but the annual sign-off requires inspection authorization. While an in-flight operational check may not be required it is very worthwhile. The pilot making the flight should sign the logbooks.
FAR 43.9(a) compliance
Work done, date completed, certificate type/number, signature. TT (total time) not required
FAR 43.9 requires that the person performing preventive maintenance must record the work in the maintenance records. The record must contain a description of the work, the date of the work, the name of the person doing the work, and approval or disapproval the aircraft for return to service.
Return to service by FAR 65.95
FAR 145 for propellers, instruments and avionics
Need not be listed in logbook but separate discrepancy list must be signed off
ADs are written in the blood of pilots after the fact.
An AD from the FAA can be as little as a placard or as much as removing a wing. Since the AD affects airworthiness, compliance with an AD directive determines the definition of airworthiness. An airplane is not to be flown unless all Ads have been complied with.
An AD is actually a Part 39 FAR with the force of law. An AD is time sensitive compliance that dictates what must be done and by when as well as how. The ferry permit allowance is usually a part of every AD notice. It is the owner or operator who is the responsible party. Any time an AI signs off an annual inspection the AD compliance is met at least on paper. An AD is a life or death matter.
FAR 91.403(a) requires that an AD compliance record be kept. Some AD are one-time and others recurring. They notify aircraft owners and others of unsafe conditions and what must be done to operate the aircraft. ADs may be of emergency situation, which requires immediate compliance, or less urgent nature with some time slack allowed. AD's are FAR's and must be complied with unless exempted. There is no 'overfly allowance as may exist with inspections. FAR 91.417 requires a record be maintained showing status of all AD's applicable to an aircraft. This often is on a separate sheet.
Difficulty Reports (SDRs)
SDRs are mechanics' report on maintenance problems. These are collected by the FAA and aircraft manufacturer and passed on to maintenance facilities as ADs (Airworthiness Directive) or as a maintenance suggestion. SDRs make up about 10% of all reported problems.
The most common items reported are those under the greatest stress. Exhaust valves, crankshaft weights, and valve train problems are usual. Cylinder reports relate to cracks at exhaust port area. Magneto problems apply to failed coils. Certain engine models are subject to specific reports related to inherent weakness such as case cracking in Continentals. Lycoming has engines with valve wobble problems. If ever you own an airplane, get an SDR listing for it.
Issued by manufacturer to advise of service problems and solutions. The solution is not mandatory as with an AD. Maintenance Records. The owner or operator of an aircraft shall have an aircraft inspected as prescribed and shall between inspections have defects repaired as prescribed. Additionally, he shall ensure that maintenance personnel make appropriate entries in the aircraft records indicating that the aircraft has been released for service.
Any record entry must include a complete description of the work done, date, and name of mechanic. If the mechanic signs the entry it indicates that the aircraft is returned to service. This signature is a pilot's assurance that the aircraft has been returned to service with the work completed.
Major maintenance requires special documentation on FAA Form 337 with a signed copy for the owner and another for the FAA. Any change in the operating limits of the aircraft must be revised with new figures. The owner is responsible to see that this is done.
Temporary records list all minor maintenance as well as 100 hour inspections. These records can be discarded when the work is repeated, superseded or at the end of one year. Permanent records list the total service time of airframe, status of life-limited parts, time since overhaul, current inspection status, status of Airworthiness Directives (Ads), list of current alterations, and current operating limitations including weight and balance figures.
Part of every annual or 100 hour inspection is a compression check. This involves removing the spark plugs, placing a pressure dial in place of the spark plug and watching the pressures change while turning the propeller. The base pressure is always 80 pounds per square inch in a cylinder. The legal minimum for an engine is 60 psi. Readings are usually shown in the logbook as 68/80. When over half of the cylinders read poorly an overhaul is due.
--A top overhaul will resurface the cylinders by honing or boring to oversize; replace the valves, valve seats; and inspect cylinders and install new rings. A major overhaul does all of the above but reworks the whole engine. An overhauled engine can be returned to service with the total time of the engine being accumulated.
If the factory does the work it is called a remanufactured
engine and the logbook begins again at zero just like a new engine.
--The owner/operator is responsible for all required maintenance, inspections and logbook entries on an aircraft. FAR 43 gives entry examples of 'appropriate" entries. This includes compliance with the FARs such as FAR 91.403(a) and FAR 91.405. 91.405 requires maintenance sufficient to keep aircraft airworthy. The owner-operator must retain the logbooks, be liable that proper entries are made, and be able to make them available to the FAA. .
--All records of maintenance and inspections require that entries say what has been done, the date of completion, signature and certification of the one doing the work and sign-off. A proper sign-off applies only to the work done. An inspection does not make the aircraft airworthy. An aircraft is airworthy only when work specified in the inspection as being required is completed and signed-off.
vs Zero Time
A zero-time engine must be rebuilt to the original standards of the manufacturer and begins time anew.
--FAR 91.213(d)(2) covers inoperative equipment. This requires
that any inoperative instrument or equipment have a signed placard
FAR 43.11 as well as logbook entries regarding the action taking.
Approval for return to service is required. Maintenance is the
owner/operator responsibility; airworthiness is the pilot's.
(See MEL above)
--FAR 91.7(b) "The pilot in command of a civil aircraft is responsible for determining whether the aircraft is in a condition for safe flight." If anything untoward happens the FAA gets to second-guess the pilot's decision. The regulations on maintenance and inspections are in FAR 91.403(a) and 91.405. 91.3 states: "The pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft. Again, if anything untoward happens the FAA gets to second-guess the pilot's decision. The PIC determines airworthiness in the preflight, review of paperwork and checking aircraft maintenance records. The aircraft must meet and continue to meet it original type design data unless approved changes are made.
Legal fault is determined by the relative responsibility of the parties involved. FAR 91.3 gives the primary responsibility and final authority to the pilot. The last mechanic to work on an aircraft is the one who takes the responsibility, even if another did the faulty work.
Aircraft No: Make: Serial Number
AD # Date Subject Compliance Method of Date of Airframe Component One-time Recurring Next Authorized and Received Due Compliance Compliance Total Time Total time in Compliance Signature
Amend Date/Hours Service at Service at Date/Hours Certificate
Number Other Other Type & #
Aircraft Record keeping Requirements of Part 91
Regulation Required Required Recordation Retention
Records Entry Location Requirement
91.411 Altimeter and Encoder Date and maximum altitude Maintenance Log 24 months
Signature, # Permanent
91.413 Transponder tests Test, date, signature # Maintenance log 24 months
91.417(a)(i ) Preventive, alternations Work performed, date completed Maintenance log Until repeated,
91.417(b)(i) 100 hr, annuals, required, Signature, certificate # of person Component log suspended,
or approved inspections returning aircraft to service or one year
91.417(a)(i) Total time in service Identification /serial number Maintenance log Indefinite
91.417(b)(i) airframe, engines, Total time since new/overhauled Component log
91.417(a)(2)(ii) Status of life-limited parts Identification /serial number Maintenance log Indefinite
91.417(b)(2) airframe, engine, propeller, Total time since new/overhauled Permanent record
or appliance iii Time since last overhaul Identification/serial number Maintenance log Indefinite
as required on time basis Total time of service since Permanent record
last overhaul .
iv Inspection status, time Type/time of last inspection Maintenance log Indefinite
since last defects found, items deferred Permanent record ____________
v Status of ADs, time/ date DA number, revision date, Maintenance log Indefinite
when next required date of compliance, method AD Compliance record
and time/date of next action Permanent record
Signature/ Certificate # .
vi Form copies prescribed by Specified on Form 337 Form 337 attached Indefinite
FAR 43.9(a) for major alternation
An aircraft will have a long life only if it is operated and maintained according to the manufacturer's recommendations. Some service areas require more frequent attention. Typical of these is:
--Wing spar capstrips and attachments
--Fuselage carry through structure for landing gear, wing and tail
--Tail spars and attachments
--Hinge points and attachments for all control and lifting surfaces
--Control balance weight attachment
--Cabin structural and seat security.
--Engine mounts, nose gear and propeller
Keeping an aircraft clean greatly improves both its appearance and its performance. When you clean an aircraft you learn a great deal about its construction and maintenance. You become aware of small defects and maintenance problems. Cleaning protects the thin layer of paint from the corrosion potential of dirt and airborne chemicals. Detergent and water are the best aircraft cleaners. If heavy grease must be removed be sure to obtain something other than a household cleaner should be used. Specifically, get a degreaser designed only for aircraft use. Pressure washers remove needed lubrication deep inside ball joints.
If the aircraft is in a high corrosion environment then the only way to
protect the metal is to perform some type of treatment. Go to the Corrosion X
web site http://www.corrosionx.com/tech.html
and read up on what it does and how it works,.
Only aircraft type cleaners should be used on plastics and Plexiglas. Using a dry cloth on Plexiglas will cause an electrostatic charge to develop what will attract dust. Washing is the best cleaning method for Plexiglas.
Oils and solvents from the ground or in the air damage natural rubber more than synthetic. Light, especially sunlight will affect the durability and elasticity of rubber. Keep your tires both clean and out of direct sunlight. Keep all rubber surfaces free of hydrocarbons.
Frequent use of a specific aircraft gives the pilot an opportunity to determine what normal operation feels and sounds like. Knowing this makes early detection of abnormal conditions more easily detected. Every part of an aircraft has a finite life; the way the plane is treated has a direct relationship to maintenance costs. Training flights with their multiple takeoffs and landings are significantly harder on aircraft than normal usage.
The use of WD-40 is not recommended on aircraft. It is not recommended because only a light lubricant is left after the solvents evaporate. Use Kroil or ACF-50 available through aircraft parts houses.
The use of steam cleaning and pressure washers on aircraft is not good practice since lubrication points are not sealed. Open bushings and pivot points must be dismantled to grease. Pressure washes flush out the oil and will wet the interior making it subject to corrosion.
The pilot who first flies an aircraft after maintenance actually returns it to service. A logbook entry under 91.407(b) is only required if flight performance or operation is changed. You are a test pilot any time you fly after even the most minor aircraft maintenance has taken place. Don't fly if you do not have the experience and qualifications for the flight. Just because you are single engine rated does not mean that you are safe to fly an unfamiliar plane. Find out what maintenance was done and by whom. Talk to the mechanic so as to separate the flight critical from the cosmetic.
Human error in maintenance is not restricted to the owner/ maintenance. Accident statistics frequently show that maintenance is a factor due to:
1. Improper component installation
2. Use of wrong or illegal parts
3. Improper electrical wiring
4. Tools left in aircraft
5. Inadequate lubrication
6. Aircraft panels improperly secured
7. Fuel/oil caps improperly secured
8. Gear/control bolts improperly inserted or secured
Maintenance life extends far beyond the end of the job. Work properly done will have a life of thousands of flight hours and years of time. Work improperly done on an aircraft is like flying with a time bomb. Maintenance that deviates from the expected norm or procedures is an accident waiting to happen. Insignificant problems can have serious consequences. Aircraft systems are designed to prevent minor maintenance mistakes. However, human error exists as an unavoidable reality. Beyond human error lies problems in the organization. Stress exists in organizations as well and individuals. Communication reduces stress.
Considerations might be:
--Are the rules there, or there to be evaded?
--Does money make short-cuts easier to justify?
--When a problem occurs, what is done about it?
--Is there a complaint format for all concerned?
--How are mistakes handled?
Engine work is flight critical. You can determine internal maintenance only by consulting on what was wrong, what was done and comparison with the maintenance manual. Going over all wire and tube connections to make sure that they are tight can check engine maintenance. Check all clamps and welds. Use an inspection mirror if you can. Make sure all bolts and nuts are secure. Check engine control linkage for security and wear. An engine that runs rough at start or has intermittent roughness may have sticking valves. Properly operating engines will have exhaust stacks that are powder gray or tan. Soot deposits show rich operation or excessive oil contamination, fouled plugs, pre-ignition and detonation. If fuel or hydraulic lines have been repaired it might be well to runup the engine to check the lines. If work has been done on the aircraft interior be sure to check fittings, wiring, catches and latches. Preflight all the controls, hinges, lock nuts, cotter pins, safety wire and cable tension. Shake the plane by the wingtip to see if anything rattles or comes off.
Review the POH on the preflight, emergency procedures and operational limits. Let ATC or others at the airport know where you will be going and when to expect you back. Do a careful runup, perhaps with someone outside to keep an eye on things out of the pilot's view. Plan all your "what ifs" and depart gaining altitude so as to get back if necessary. Accident files show that all too many accidents occur after some kind of maintenance has taken place.
A more careful preflight should be made after all maintenance. The less a plane flies the more careful should be the preflight inspection. Become familiar with the papers and logbooks of any aircraft you fly. As a pilot you should become familiar with the aircraft manual for every plane you fly. You should first go through it quickly to get an overview of what it contains. Next you should study it section by section and become familiar with pertinent information and know how to find any that may be required for a cross-country or for a checkride.
that Go Wrong
--A pilot during training should be exposed to recognizing and understanding the danger signs warning of both eminent and impending operational problems.
--There are many visual signs such as smoked rivets, cracks and leaks. Non-structural cracks can be stop-holed to prevent further growth. The hole relieves stress. Leaks can be normal or a problem. Propeller and hydraulic leaks are serious and should be brought to the attention of a mechanic.
--There are tactile and auditory signs from moving the controls, and structure.
--Learn to listen for changes in engine, propeller and wind sounds. The way an aircraft vibrates is a prime indicator of its health. Any unusual vibration is sufficient warning to land as soon as possible.
--Every aircraft has its own smell. Electrical smells from insulation are distinctive. Any smell that persists is a warning that a fuse or breaker has failed or been bypassed. Turn off the master switch. You can isolate the problem by turning on one breaker or fuse at a time until you locate the problem.
Definition: An incident is an occurrence, not an accident, affecting the operation of an aircraft or its safety.
Part/Section 830.5 Immediate Notification
Required by operator of any civil aircraft to the NTSB when:
a. Accident or listed incident occur
1) Flight control malfunction
2) Inability of crew member to perform
3) Turbine failure
4) In-flight fire
5) Aircraft collision
6) Property damage over $25k.
7) (Applies to large aircraft)
b. Aircraft overdue; suspected accident
Part/Section 830.6 Required Information
a) Aircraft identity
b) Identity of owner/operator
d) Date and time of occurrence
e) Last departure and intended landing
f) Aircraft position at occurrence
g) Souls aboard and condition
h) Kind of occasion, weather and damage done
i) Dangerous articles carried
Part/Section 830.10 Preservation of wreckage and records
a) Preserve all records related to flight and occurrence
b) Maintain undisturbed condition
c) Protect the public
Part/Section 830.15 Reports and statements to be filed
a) Reports. The operator shall file a report of Form 61201/2 within ten days for an accident. A report on an incident for which immediate notifications required by Sec 830.5 (a) shall be only as requested.
(b) Crewmember statement required setting forth facts, conditions, and circumstances.
(c) Reports to be filed with nearest field office of NTSB.
Expert pilots in new planes achieve aircraft performance numbers. Repeated flights are made to get the best numbers possible. Even so, the POH is replete with conditional statements of conditions that can affect performance. Aircraft before 1976 have figures in miles per hour. In 1976 you get a mix of statute and nautical mile data. Surface conditions, weather conditions, pilot performance, aircraft configuration all can and will make a difference.
Use long-handled soft brush. Don't touch windows. Work top down. Leave windows to last.
Knight's Spray Nine diluted 1:1 does good job without damage but don't leave on too long without rinsing. Best way to dry aircraft is to fly it. Make sure you move controls through full range of movement.
Arrow Magnolia's Carbon-X or Tomar Industries TR-1000 removes exhaust stain.
Icex at Aviall 800/284-2551
Jet Stream at 800/727-5387
Tomar Industries at 919/467-0362
Simple Green and Spray nine at auto parts and local stores.
I use 'Wash and Wax; products along with the soft scrubber kit, Gene.
Check at: www.washandwax.com
and Static Electricity
--Aircraft should be grounded to the refueling source before fuel flow begins.
--Ideally the grounding is also between aircraft, fuel source and the earth.
--Do not refuel from a source that cannot be grounded to the aircraft.
--Static build-up can occur due to fine filters, flow rate, splashing and hot/dry conditions.
--It is the fine filter-separator that increases static build-up by a factor of 100.
--The bonding wire MUST be connected before the tank is opened.
--The fuel nozzle must touch the wing or fuel cap BEFORE the cap is removed.
--By keeping the fuel flow rate slow you reduce the probability of creating a static charge.
--A composite aircraft is more likely to develop a static charge.
--Wiping the area around the fuel cap with a wet rag will help dissipate any static charge.
--Use only a metal funnel if one is required for refueling.
--Draining and sloshing fuel in tanks can build a static charge.
--The worse thing that can happen is to get away with a dangerous practice.
--Record keeping of all maintenance is a major part of the value of an aircraft.
--Unrecorded maintenance is an automatic violation of the FAR and evidence of not being airworthy.
--The owner is responsible for aircraft maintenance and responsible for the proper keeping of records.
--Required to have annual inspections. Careful timing of annual inspections can give 13-month intervals.
--Biennial inspections can last 25 months as required by the static system and transponder as well.
--Any inspection and sign-off is a momentary verification of airworthiness at the instance written.
--For IFR the VOR(s) must be checked for accuracy every thirty days. Records must be kept.
--Flight tests of maintenance are not required if all things prove no changes affecting safety occurred.
--The FAA requires by ADs (airworthiness directives) that aircraft problems be corrected.
--Some ADs have time lapse requirements and emergency ADs will ground an aircraft.
--Aircraft manufacturers issue service bulletins for changes that will evade potential liability.
--Failure of aircraft components is a relatively minor cause of accidents by percentage of total accidents.
--Maintenance accidents are caused by omission, commission, design or manufacture flaws.
--A preflight should be done suspiciously looking for the unusual or unexpected.
--Flight time should be sensitive toward the unusual and unexpected, be it sound, movement or smell.
--The engine compartment is the most likely region of problems especially related to fuel, air and ignition.
--On average only one of every 25 engine failures is related to a part breaking.
--If you sense a difficulty firewall forward prior to takeoff, don't.
--If you sense a difficulty firewall forward after takeoff, get on the ground.
--Rule #1: First do no harm
--Working on an airplane increases you understanding of the airplane
--You will preflight better once you have maintained your own aircraft
--Guided owner maintenance is the best way to learn how to do things correctly
--Aircraft maintenance requires a far different mind-set than for other devices
--Everything you use, do, remove, and replace must be airplane specific.
--There are 32 things an owner can do to or for an airplane.
--An owner is bound by the same FARs as is a mechanic.
--FAR 43.13(a) is the mother source of what, how and if things can be done.
--Compliance with any work on an aircraft is best undone with a definitive checklist and redone the same way.
--The detail of the checklist is determined by the experience of the person doing the work.
--Logbook entries are the diary of an aircraft in compliance with FAR 43.9
--Entries include work done, date finished, signature and certificate number of worker
--Fly with an emergency maintenance kit with a book for recording maintenance to be entered into logbooks.
GPS Updates as Preventative Maintenance
Recorded under preventative maintenance.
Here is the section I found in the FAR's item section (c) item 32 user preventative maintenance:
(32) Updating self-contained, front instrument panel-mounted Air Traffic Control (ATC) navigational software data bases (excluding those of automatic flight control systems, transponders, and microwave frequency distance measuring equipment (DME)) provided no disassembly of the unit is required and pertinent instructions are provided. Prior to the unit's intended use, an operational check must be performed in accordance with applicable sections of part 91 of this chapter.
Changing a Nose Tire
--Use or Make checklist and take pictures
--Chock other tires
--Use jack under nose to raise tire off ground
--Remove throughbolt cotter pin
--Remove throughbolt nut and remove throughbolt
--Remove left and right axle spacer support cups
--Slip tire, wheel and axle spacers from fork
--Set spacers (identified) aside
--Remove left side wheel bearing snap ring
--Remove the two grease seal rings
--Remove the felt and bearing from the wheel half
--Identify left side wheel parts and left side of wheel
--Identify right side wheel parts and right side of wheel bearing parts
--Break tire beads from wheel halves
--Remove wheel nuts and throughbolts
--Keep all parts so they go back where they started.
--Allow engine to cool for few minutes
--Allow engine to run at high idle on bad magneto for a bit over one minute
--Shut down with mixture
--Find cold exhaust pipe by using finger dipped in water
--Trace wires back to magneto to determine fouled plug
--Bottom plug is most likely
--Change plug and install plug lead
--Mag check can be done without cowling.
--Make maintenance entry for entry into aircraft logbooks
Plug Replacement Kit
--Wrench for high -tension spark plug wire nuts
--Plug wrench and socket
--Avoid touching the 'cigarette'
the Annual Inspection
--Get several references for any AI before you get involved.
--Having every annual inspection done at the same place may not be wise.
--Owner should pre-arrange right to participate and not pay AI to watch work being done.
--FAR Part 43 lists inspection items required.
--The annual is an inspection only by a mechanic with an inspection authorization using a checklist.
--Inspection is complete when aircraft logbook entries are completed by the AI.
--AI's opinion cannot be appealed only complied with.
--AI can be expected to document every decision by means of specification and documentation.
--All items making aircraft unairworthy are listed as a part of the inspection logbook entry.
--It is an expensive mistake to stop the inspection to fix a discrepancy. Complete inspection then repair.
--Any AD's must be complied with and logged properly.
--Owner is responsible for compliance with AD's as to when, where and how compliance was performed.
--Repair requires a certified mechanic. The AI and the A&P need not be the same person.
--A&P must make logbook entry certifying aircraft safe for ferry permit flight or
--A&P must make logbook entry certifying all of AI's entries have been complied with and aircraft airworthy.
--Final responsibility of airworthiness lies with owner. Airworthiness is determined before each flight.
--Aircraft must meet specifications of type certificate in equipment and tolerances of components.
--AC 43-13 gives approved repair procedures
Inspection by Checklist Phases
--Paperwork and ADs
--Past records reviewed
--Compliance with all ADs confirmed on plane and in logs
--New and recurrent ADs added to checklist
--Class I appliances (major components) type certificate data sheet (TCDS), STC and alterations comply
.-- Run-up and systems
-- Washing and disassembly
--Table of limits and specifications to determine if serviceable
--Owner can do preventative maintenance if IA inspects work
--Lubrication and adjustments are part of preventative maintenance
--Owner can disassemble and assemble as long as AI inspects procedure
--Post-annual run-up and systems check
--When inspection is complete unairworthy items must be corrected before airplane is returned to service
--Research inspection items to confirm tolerances specified
--AI must list all discrepancies
--A & P must complete log for every discrepancy satisfied.
--AD numbers are according to date and order of issuance in weekly grouping.
--ADs that do not apply must be noted as D/N/A
--One section of ADs are called 'One Time" another section are 'recurring' by age or use.
--ADs for a particular aircraft can exist in several different indexes and revisions even retroactively
--Changing annual inspectors will probably include the cost of complete review of AD records.
--ADs are a part of ownership.
--AD compliance is required for airworthiness.
--The AD compliance record is a required time and expense of ownership.
--The AD compliance record can be accomplished by the owner via internet and computer.
--ADs apply to the engine, airframe and propeller plus all other aircraft 'appliances'
--Compliance record must include model, part number and serial number.
--Every component of the aircraft may have an AD record.
--Registered owners receive notice of all new ADs
--Latest ADs are in plain language form
Riveting in on Riveting
--The older the aircraft the more critical are good rivets.
--Two primary elements of riveting is selection of proper rivet and method of installation.
--Riveting on aircraft requires that the riveter be properly certificated and qualified by experience and training.
--Riveted surfaces are not usually taken apart.
--A rivet is actually a two-headed bolt.
--Aircraft manufacturers rule where and when to use rivets.
--If no manufacturer advice is offered then a ‘reliable source’ must be used.
--FAA Advisory Circular 43-13-1B is considered a reliable source.
--Every re-riveted structure must mirror the original strength, flexibility, and stiffness.
--Standards for riveting are laid out in AC 43-13
--Rivets are expected to fail before the underlying metal fails.
--Common rivets are solid-shank aluminum.
--Rivets are identified by size, diameter, head, and metal-type on their heads.
--The use of similar metal in rivet to sheet metal reduces corrosion.
--Countersunk holes with flush rivets are more difficult to do properly.
--Common errors are slat, one side flat, body too short, not tight or plates not together, too tight, area buckled or bulged.
--Poor rivets should be drilled out.
An FAA Ramp Inspection Checklist
The Pilot (9 items)
FAR 61.3 & 61.5
1. Pilot certificate
2. Medical certificate class and date
3. Type of ratings by category
4. Airplane class rating
5. Rotorcraft class rating
6. Type of rating
7. Lighter-than-air rating
8. Instrument rating
FAR 61.25 Change of name or address
Aircraft Inspection (14 items)
2. Obvious defects
3. Airworthiness Certificate
5. N marking correct
6. Annual inspection
7. Transponder date
8. Compass card
9. Minimum equipment list
10. Flight manual
11. AD current
12. ELT date
13. Data plates
14. Weight and Balance
1) The aircraft must conform to its type certificate
a. When aircraft configuration and the components installed are consistent with all information that is part of the type certificate.
2) The aircraft must be in condition for safe operation.
a. Aircraft relative to wear and deterioration (examples of damage)
Records (16 items)
1. Registration is current and in aircraft. CFR 91.9
2. Airworthiness certificate in aircraft CFR 91.203(a)
3. Verify A&PI certificate number CFR 63.91
4. Current weight and balance 23.1581, 91.9
5. All AD's current in maintenance records CFR 23.23, 23.1519
6. Last annual completed: CFR 43.11 & 91.417
b. CFR 65.91 Name and certificate number.
c. 145 repair station sign off date and station number
7. Annual Inspection 43.11 & 91.417
a. Total time
b. Description of work done
c. Date complete
d. IA signature and certification number
8. Last 100-hour inspection
a. 145 Repair station signoff date and station number CFR 43.3/51/57
b. A & P date and certification number CFR 43.15, 65.85, 91.409
9. A&P/IA signature CFR 43.11 & 91.409
10. Approved flight manual up-to-date before 03-1-1979 CFR 21.5/23.1591, 91.9
11. Equipment list current and in aircraft CFR 23.29 & 91.9
12, Flight manual of POH current after 03-1-1979 w/revision number and date CFR 21.5/23.1581, 91.9
13. Alterations IAW approved STC/TSO/PMA/field approval of other FAA data/337s CFR 21.97/101/113
14.Maintenance records for engine, airframe and propeller CFR 91.417
15. FAA-accepted instructions for continued airworthiness (ICAW for form 337s) and FAA -accepted maintenance manuals. Per FAR 21.31, 21.50, 21.1529,
16. Annual/100 hour inspection checklist owner gets copy CFR 43.15 (c)
In my conversation with the FAA source of this checklist, I was told that getting through the foregoing meant that the remaining six pages were unlikely to be a problem. It doesn't look that way to me.
Cockpit Inspection (39 items)
1. Instruments and placards are correctly located per POH or T/C CFR 23.1541-1567, 91.9
2. INOP placards
a. INOP instruments removed
b. Equipment list up-dated
c. Maintenance record entry.
3. Instrument range markings: CFR 91.205/405(d) & CFR
23.1322, CFR 23.1541
b. Fuel pressure
c. Fuel quantity
d. Oil pressure
e. Oil temperature
g. Heading indicator
h. Vertical speed indicator
i. Turn and bank
j. Gear indicator
4. Compass card is there and legible CFR 23.1547 & 25.1547
5. Additional instruments not on equipment list or 337
6. Type of clock installed original analog or digital working AC 20-94
7. Nav radio P/N 1 and P/N 2
8. Conforms to type certificate (TC) per POH (see 5 & 6 above)
9. Check seat belts for stitching, cuts or worn CFR 91.107 & 23.785
10. Seat belts proper storage and marking TSO-22 7 23.785
11. Seat belts plastic locking ring missing front and back seats TSO-22, CFR 45.14
12. TSO-22 marking on seatbelts CFR 45l.15, CFR 91.205(b)(13,14)
13. Shoulder harness required after July 18, 1978 CFR 23.785(g)(1)
14. Seat rail holes elongated requires AD check CFR39
15. Worn seat material CFR 25.853 for a CAR-3.388 aircraft Part 91 & 23.853, AC 43.13-1B Para 9-61
16. New Interior material certificates CAR-3.388 & CFR 23.853/25.853
17. Interior worn and if new has certification sheets (Has interior been altered or changed?) CFR 21.303/43.11
18. Cockpit fuel smell CFR 23.863
19. Data plate information matches registration FAR 45.11/13 & 47.3
20. Intercom jack, how many, any extra and required Form 337
21. Fire extinguisher gauge
22. Oxygen bottle AC 43.13-1b para 9-51
23. Instrument filter covers installed
24. Windows stop-drilled, cracked, or crazed CFR 23.775
25. Seat back locks broken CFR 23.785
26. Flap, gear and other knobs installed CFR 23.781
27. Yoke chain safety wired or loose CFR 43
28. Electrical wiring more than 1/2 inch of slack CFR 43.13 1B para 11-118
29. Electrical wiring clamps/marking as required AC43.13-1B sec.11Z
30. Ty-wraps on items of mass in the cabin CFR 23.561
31. Loose wires under the dash not clamped CFR 23.1351
32. General cleanliness and loose equipment 23. 1301
33. Fuel selector moves to all positions and placarded
34. Oxygen system and supply condition CFR 23.l144 thru 1453
35. Battery vented overboard 23.1353 & AC 43.13-1B para 11-22
36. Fire extinguishing agent CFR 23.1197
37. Cockpit control knob shape CFR 23.781
38. Engine control proper installation and operation CFR 23.1141
39. Brake master cylinder leaking, check left/right CFR 23.735
Aircraft Exterior Inspection (34 items)
1. Nationality and registration marks per FAR 45.29. 3-inch markings per Jan1, 1983 and repaint Over 30 years 2 or 12 inch CFR 45.22(b)
2. Fuel placards on left and right CFR 45.22(b)
3. Fairing cracked, hardware missing CFR 24.607, CFR 23.1193
4. Tire condition, wear and cuts AC 34.13 para 9-14
5. Landing gear struts condition AC 43.13 para 9-2/4
6. Landing gear extension AC 43.13 para 9-2/4
7. Landing gear farings condition CFR 23.607, CFR 23.1193
8. Brake pads and line conditions CFR 23.735
9. Wing dents, cracks, rivets, corrosion lights CFR 23.1385
10. Flap cracks, loose hardware, installation, stop-drilled, cracks CFR 23.655/697
11. Fuel vent direction CFR 23.975
12. Aileron cracks, loose hardware, installation cable rigging loose, annual/100 hour inspection CFR 23.655/685/689
13. Deicer boot condition worn, holes, debonded CFR 23.1416/1419
14. Static ports no paint, clear CFR 23l.13l25
15. Pitot tube hole not plugged and last inspection date. CFR 23.1325
15, Rudder movement, bearings, racks, repairs CFR 23.685
16. Cable rigging tensiometer test every 100 hours/ annual CFR 23.589
17. Electrical bonding strap condition CFR 23.867
18. Rotating beacon installation, corrects/doubler after 08-11-71 CFR 23.1401
19. Anticollision light system CFR 91.209(b)/CFR 23.1401
20. Navigation lights proper color CFR 23.1385-1399
21. Elevator torque tube adapter, rivets condition CFR 23.675
22. Horizontal stabilizer cracks, rivets, installation, safetied, stop-drill cracks, stops CFR 23.571, 23.675
23. Door latches and locks, sprung, seals worn CFR 2l3l.1557
24. Windscreen clear, scratches, racks, CFR23.775
25. Antenna installation, doublers per 43.13 2A, CFR 23.571/572
26. Fabric covered aircraft condition AC 43.13-B chapter 2
27. Emergency exit placards CFR 23.15l57(d)
28. ATC transponder FAR 91.413 date and 24 calendar month check
29. ELT TSO-C91a/TSO-C126 12 month check
30. Altimeter test CFR 91.411 24 month check
31. Mirrors on wings require form 337
32. Landing light covers cracked, missing hardware
33. Landing gear retraction test CFR 23.l479
34. Emergency gear extension performed CFR 23.479
Engine Inspection (Reference: CFR 23 Subpart E powerplant)
1. Engine data plates matches type certificate CFR 45.13
2. Proper engine installed per type certificate or STC CFR 23.901
3. Engine/propeller per type certificate of STC CFR 43
4. Certification of instruments and engine accessories installed with 337's CFR 4l5.15/23.1305/ 23.1543/ 23.1309/ 23.
5. Engine cowl loose/missing hardware by location CFR 23.1193
6. Firewall bent, racked or missing fasteners CFR l23.1191
7. Engine mount structure for cracks, dents and condition CFR 23.901
8. Engine shock mount for cracks, worn, condition 23.901
9. Flex tubing condition CFR 23.1183
10. Clamps installation and type CFR 23.993
11. Engine oil leaking (location) CFR 43
12. STC for air filter bracket if installed & Form 337 CFR 43
13. Condition of baffle seals and installation and type of material
14. Propeller seal leaking CFR 23.907
15. Propeller clearance CFR 23.925
16. Propeller for nicks, cracks, and damage AC 43.13-2B para 8-73
17. Propeller spinner for cracks or missing screws (none allowed), nuts safety wired. Service Letter reference.
18. Propeller grinding on rotation AC43.13-1B para 8-2 (c)(2)
19. Propeller nuts properly torqued CFR Appendix D
20. Wire chafing, fuel lines, no wires under fuel lines AC43.13-1B
21. Electrical wire maximum 1/2-inch slack between supports AC43.13-1B figure 11.9
22. Engine/electric fuel pump and wiring condition
23. Ignition harness condition
24. Starter ring condition of teeth
25. Alternator/generator drive belts condition
26. Cracked cylinder fins and rocker cover leaks (locations)
27. Exhaust system cracks, defects and installation (location)CFR 23.1121
28. Muffler cracks or leaks pressure tested CFR 23.1121
29. Carburetor heat box condition of holes. proper hardware, screws and nuts CFR 23.1121
30. Engine controls safetied and checked for travel AC 43.13-1B para 7-122 thru 127
31. Injection fuel lines checked. Recurring AD at 100 hours CFR 39
32. Fuel bowl leak CFR 23.999
33. Fuel lines condition, movement/clamping CFR 23.993 & AC 43.13-1B para 8-31
34. Carburetor security, throttle arm/ bushings condition
35. Crankcase for cracks, leaks and security of seam bolts
36. Differential compression test, 80psi/60 psi cylinder CFR 43 appendix D & AC 43.13-1B paragraph 8-14 25% difference means problems
37. Vacuum pump lines, clamps, condition
38. Supercharger overall condition
39 Oil filler opening placard CFR 23.1557(c) (2)
Aircraft Records and Owner Responsibilities (6 items)
1. Have the aircraft inspected CFR 91 subpart E
2. Owner SHALL insure appropriate maintenance entries are recorded CFF 91.405(b) & 43.9/11
3. Receive a copy of any form 337 for maintenance performed on aircraft CFR 43 appendix B (a)(2)
4. Work performed by persons authorized CFR 91.405
5. Between inspections discrepancies repaired CFR 91.405
6. Keep records until work is repeated or superseded by other work or for 1 year after the work is performed
Aircraft Inspection (23 items)
Some of reported items were found on new and low time aircraft that verifies the importance of a thorough pre-flight
--Aileron control cable not over pulley
--Aileron cable improperly installed in bellcrank - cable retaining pin was installed
--Bolts loose on the vertical and horizontal stabilizer fin attachments
--Broken and cracked electrical terminals
--Control cable turnbuckles not sifted
--Flap follow-up cable chafing on brake line
--Foreign items in fuel cells/tanks
--Fuel lines twisted, bent, kinked thus obstructing flow
--Fuel lines chafing due to inadequate clamping
--Incorrect propeller bolts installed
--Jam nuts drilled but no safety wire installed
--Lock clips missing from control cable turnbuckles
--Loose rivets in horizontal stabilizer leading edge
--Main wheel tires do not clear wheel bays
--Numerous drill chuck marks in aft face of pressure bulkhead. Required replacement.
--Oil lines leaking at connections
--Primer line "T" fitting not installed
--Propeller blade retention ferrules under torqued
--Right elevator trim cable wrapped around right primary rudder control cable
--Rivet holes drilled but rivets not installed in several different areas
--Rudder cable bellcrank attachment bolts loose
--Rudder cable bolts fitted upside down
--Unreliable fuel quantity indications
FAR Part 39 Airworthiness Directives
39.l (a) An unsafe condition exists
(b) Will exist in similar products
39.3 Aircraft operation prohibited with product
Condition correctable by inspection and replacement. Inspection may be one-time or repetitive. Proof of purchase cannot show compliance. Safety is not cheap but cheaper than an accident. Any aircraft part should be traceable back to point of origin. Counterfeit part resembles original. Suspected Unapproved Part due to finish, size, color, identification, or paperwork. Best detected during receiving state. Check Http://www.faa.gov/avr/sups.htm
Require supplier to certify in writing authenticity of parts.
Keep packaging. Check for:FAA Form 8130-3 (approval tag)
JAA form One
Records of approval for return to service
FAA TSO markings
FAA PMA symbols
Way to Weigh (Web Posting)
1. The manufacturer of an aircraft normally capable of carrying four passengers, luggage and full fuel produces a new model. Looks the same powered the same flys the same. Standard practice is not to weigh every aircraft made but only every sixth one of a similar design.
2. While weight and balance is usually, if not always, done by draining all useable fuel, this particular model is certified as having all fuel drained. It makes the useful load look better by about 40 pounds.
3. This particular aircraft seems capable of only carrying three passengers using the factory figures for useful load with full fuel...
4. The aircraft is re-weighed in 2004 using the unusable fuel method. All at once the aircraft weighs about 40 pounds more. Not only that a person familiar seems to believe that the aircraft as certified is actually 200 pounds over gross as normally flown with four passengers, luggage and fuel. No one can figure out just why.
Does the re-weighing using a different method void or amend the certification?
Does flying the aircraft 200 pounds under gross make the aircraft legal?
Who, besides the pilot is going to be in trouble?
Web Response to Way to Weigh
With an airplane, as Avemco has clearly said, "it depends on the underwriters and how they word the policy". If the answer to the over-gross question was no sweat, they would have said no sweat! What they said was it depends on the underwriter. Those espousing here about old wives tales and newsgroup gossip might want to take note of this. The bottom line on this is that it's far from being an "old wives tale" as some here have indicated. Aviation insurance is highly specific to both the individual airplane and the individual pilot.
Even though flying the airplane over gross might not be listed or worded on one person's policy. It is absolutely no indication that it isn't either listed as an exclusion or covered in a legally binding general restriction on another part of the policy that states the airplane has to be legal for the insurance to be in effect.
Anyone who believes the FAA considers a Standard Airworthiness Certificate to be valid on an aircraft being deliberately flown over gross in my opinion is making a serious mistake in judgment. The FAA clearly states that an aircraft with a Standard Airworthiness Certificate MUST be in safe operating condition, and flying it over gross in excess of it's written GW limits is NOT safe operation! The fact that some policies are not showing exclusion clauses that cover flying over gross should in no way be taken as a general indication that system wide; owners are covered flying their aircraft over gross.
The main issue is the invalidation of the Airworthiness Certificate by flying the airplane outside the parameters of that Certificate. Depending on the exact wording of an individual policy, you will either be insured or you won't. It behooves every insured pilot to read carefully the exact wording of their policies and to check with their insurance companies.
---Records and logbooks are like money value to the associated aircraft
---Changing oil is #1 way to care for engine
---Keeping aircraft clean was #2 way to care for aircraft
---Aircraft aluminum has thin outer layer of aluminum to prevent irreversible corrosion underneath
---The pilot owner of an aircraft is under FAR Part 43 authorized to do and record preventive maintenance
---Every thing done to an aircraft requires entry into the logbook to return the aircraft to service.
---A mid-year annual inspection is a good idea to be done with pilot assisting an AI
---Only authorized replacement parts can be installed on an aircraft.
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Related Pages 2.20, 2.25, 5.72, 5.73
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