A Pilot's Guide to Preventive Maintenance
AOPA's Guide to Preventive Maintenance
In our daily contact with thousands of aircraft owners and pilots, one major theme prevails. AOPA members are deeply concerned about the high costs associated with owning and operating general aviation aircraft.
As pilots, most of us are not mechanics by training or occupation, yet many of us derive satisfaction from tinkering with mechanical things, especially aircraft. By performing routine maintenance on our own aircraft we not only gain personal satisfaction but also become better educated about the equipment we fly, making us better and safer pilots. The opportunity also exists to save a substantial percentage of the annual maintenance costs associated with aircraft ownership.
Many aircraft owners, however, never attempt to work on their aircraft for a variety of reasons. Chief among these is a general sense of intimidation by the complexity of the airplane. Another is the fear of doing something wrong and running afoul of the local FAA inspector. Similar to this is the concern by the pilot that he or she may perform some function incorrectly, potentially jeopardizing the pilot's own safety and that of passengers at some future date. These are all very legitimate concerns, and it is our hope that this booklet will help address each of them.
Probably the most common reason for pilots not to perform their own routine maintenance is the belief that the FAA will permit only such a limited amount of work to be handled by the owner that it is not worthwhile to even attempt it. In fact, there is a rather broad array of tasks that we as owners and operators of type certificated aircraft can legally perform without the ongoing supervision of an aviation maintenance professional. And, with a little additional assistance from your local aviation maintenance technician (A&P mechanic), there is not much you can't do yourself.
But hold on! Before you head off to the airport with wrench in hand to fix all those annoying little maintenance items you noticed on your last flight, it is important to fully understand your privileges and responsibilities as a certificated pilot in performing routine maintenance. The Federal Aviation Regulations spell out in some detail what pilots (who are not certificated airframe and powerplant mechanics or repairmen) may do to maintain their aircraft. These functions fall under the heading of "preventive maintenance" to distinguish them from more complex maintenance, repair, rebuilding, or alteration functions which a pilot is not permitted to perform without direct supervision of an aviation maintenance professional.
FAR Part 43 specifies who may do what to an aircraft in the way of maintenance, repair or alteration. It requires that only properly certified mechanics work on aircraft and "okay" them for return to service. However, it does allow preventive maintenance to be performed by a certificated pilot, holding at least a Private certificate, on an aircraft owned or operated by that pilot, provided the aircraft is not used in commercial service. The responsibilities for a pilot performing preventive maintenance are very similar to those imposed on the certificated mechanic performing other duties. The FARs require that anyone who works on an aircraft must have the appropriate maintenance and service information available. This means quite simply that before you set about performing preventive maintenance items on your airplane, you must first have the proper maintenance manuals available. As you read toward the back of this booklet you will find a list of sources to obtain maintenance manuals for your particular aircraft. These manuals can be fairly expensive, but we guarantee that they will save you considerable time, money, and aggravation in the future. And, you must have them!
Another commonality between the mechanic and the pilot performing maintenance is that all maintenance actions, including preventive maintenance performed by the pilot, must be recorded in the aircraft maintenance records. This should be done carefully and religiously, not only to comply with the legal requirements of the FARs, but also from the standpoint of keeping an accurate maintenance history of the aircraft. Later in this booklet you will find some suggested logbook entries that you can employ in "signing off" the work that you do.
If you stumble into a task that seems unfamiliar, don't be afraid to seek some professional advice. Get some help from your local mechanic before taking on any job you have not done before if you are not confident that you can accomplish the work successfully. And remember, your mechanic is trying to earn a living, so compensate him for his time and advice. You'll be more likely to get it again in the future that way.
This publication has been developed by AOPA staff pilots and mechanics in order for pilots to better understand what is permitted under the privileges of preventive maintenance and the obligations that are imposed when performing maintenance. We sincerely hope the information contained in this booklet will be helpful to you and wish you many rewarding hours under the cowling.
Please read carefully the following 32 items that are permitted under the privileges of preventive maintenance and the short brief that follows. They will help you better understand your privileges. Item number 30 pertains to primary category aircraft only. To understand what is required when performing preventive maintenance, you should also read thoroughly AC 43-12A, which follows those 32 items.
Preventive maintenance is limited to the following work, provided it does not involve complex assembly operations:
- Removal, installation, and repair of landing gear tires. Tire changes may not be as simple as anticipated; here are some important considerations: Know the proper jacking procedure for your aircraft as outlined in the service manual. The aircraft should be jacked in an enclosed hangar. If the aircraft must be jacked outside, take into consideration wind and proximity to taxiway; Consider how the removal of wheelpants will affect other systems; Know the type of brake system and how it may affect wheel removal and installation; Removal and installation of the wheel-retaining nut requires a special touch. Have your mechanic demonstrate how freely the wheel should rotate after being installed. Replace the old cotter pin with a new one of proper size;
WARNING! Due to high air pressure don't forget to deflate the tire prior to disassembly of the wheel halves for tire and tube replacement. Another important consideration is the proper torque on the bolts securing the wheels halves together.
- Replacing elastic shock absorber cords on landing gear. Shock absorber cords, commonly called bungee cords, are found on many types of airplanes. Examples: Cub, Aeronca, and Pitts. At first glance, changing the bungee cords looks like a simple task. Believe us, if you don't have the proper tools, it's like going hunting for a grizzly bear with a hickory stick. Don't do it.
- Servicing landing gear shock struts by adding oil, air, or both. The FARs allow the adding of oil and air to air-oil or oleo struts. However, many manufacturers recommend the use of nitrogen instead of air, which helps to prevent the possibility of corrosion. It's also a good idea to keep that dirt and grime removed from the bottom of the shock strut by wiping it down using a clean rag with some MIL-H-5606 on it. This will help to increase the life of the strut.
- Servicing landing gear wheel bearings, such as cleaning and greasing. Cleaning and greasing wheel bearings is an art. There are several very important steps to follow when servicing the wheel bearings:
- Cleaning — This must be done thoroughly, using a cleaner such as Varsol.
- Inspection — Now that the bearing is cleaned, inspect the roller and inner and outer races for deterioration.
- Greasing — If you don't have access to a bearing grease machine, get ready to get dirty. Take a nice dab of grease and put it into the palm of your hand. Force the grease into the side of the bearing until the grease comes out the other side. Now you have accomplished the ultimate in preventive maintenance.
- Replacing defective safety wiring or cotter keys. Always place safety wire in a manner to cause the item to be tightened. Use approved safety wire of the thickness specified, normally .032 and .041 (refer to service manual for recommended safety wire to be used). Don't over-torque or under-torque nuts or bolts in order to align cotter key holes. Do not use safety wire bought from a hardware store; it's not approved for aircraft use.
- Lubrication not requiring disassembly other than removal of nonstructural items such as cover plates, cowlings, and fairings. If you are going to lubricate moving parts on your aircraft, first refer to the lubrication section in the service manual for the type of lubricant and how to apply it. You should also check with your A&P mechanic before getting started. Many Piper aircraft have Teflon-coated aileron hinges and should not be lubricated. Engine oil change is one of the simplest tasks that pilots are allowed to do under the privileges of preventive maintenance, but it's one of the most critical.
Start by checking with your mechanic for any airworthiness directives that apply when changing engine oil in your airplane. One that comes to mind is Avco Lycoming 80-04-03 R2, which requires using an additive in the engine oil and inspection of the oil filter. Only an A&P mechanic can sign this AD off and return the airplane to service.
Many people today are doing oil analyses. One oil analysis will tell you very little about your engine. You will need to develop a history of oil analyses by taking oil samples from the same location and after the same number of hours each time you collect the oil samples. Then you will start to develop a history on what's happening inside the engine.
Another good idea is cutting the oil filter open and rinsing the filter element in a bucket of Varsol or a similar material. Use a magnet to extract ferrous particles, and save them for later examinations. Filter the remaining solvent through a coffee filter, and examine the remains. You should ask your A&P mechanic for advice on what you see the first couple of times. Many people will save the coffee filter and particles until the next engine oil change for comparison.
- Making simple fabric patches not requiring rib stitching or the removal of structural parts or control surfaces. In the case of balloons, the making of small fabric repairs to envelopes (as defined in, and in accordance with, the balloon manufacturer's instructions) not requiring load tape repair or replacement. Remember: no rib stitching or control surface repair.
- Replenishing hydraulic fluid in the hydraulic reservoir. MIL-H-5606 is the common type of hydraulic fluid used in light airplane brakes and hydraulic gear systems. Use of other than recommended fluid can cause damage to seals, O-rings, and other parts of the system. Be sure you add only the same kind of fluid as that already in the system; follow instructions in the service manual.
- Refinishing decorative coating of fuselage, balloon baskets, wing tail group surfaces (excluding balanced control surfaces), fairings, cowlings, landing gear, cabin, or cockpit interior when removal or disassembly of any primary structure or operating system is not required. Refinishing decorative coating: At first glance, this sounds like a simple task, but it becomes complicated very fast. You should start by checking the service manual for recommended procedures and material to be used. Then discuss your intentions with your mechanic and a reputable paint shop attendant. You will need a place to buy those materials and dispose of the unused materials and remains, and they may prove to be excellent sources.
Many aircraft manufacturers require control surfaces to be balanced after painting, so leave those parts to the professionals. Remember: The quality of paint and workmanship will affect not only the value of your airplane, but performance, as well.
- Applying preservative or protective material to components where no disassembly of any primary structure or operating system is involved and where such coating is not prohibited or is not contrary to good practices. Check with your mechanic prior to applying preservatives or protective materials to ensure their lasting effect. Some problem areas that have been noted are alternator drive belts and autopilot servo clutches.
- Repairing upholstery and decorative furnishings of the cabin, cockpit, or balloon basket interior when the repairing does not require disassembly of any primary structure or operating system or interfere with an operating system or affect the primary structure of the aircraft. When repairing or replacing upholstery, you are required to meet the original type design requirements. Use only material that has met the burn test requirements. The supplier of the aircraft interior will provide you with the needed paper work for your logbook. Do not buy materials from a local upholstery shop because your mechanic may ask you for the certification paperwork at the next annual.
- Making small simple repairs to fairings, nonstructural cover plates, cowlings, and small patches and reinforcements not changing the contour so as to interfere with proper air flow. Be careful; what you consider a simple repair may not be. You should refer to the service manual and then ask for advice from your A&P mechanic before making a judgment call. You must use approved material and procedures to do the repair.
- Replacing side windows where that work does not interfere with the structure or any operating system such as controls, electrical equipment, etc. Remember that we are talking side windows, not windshield; leave that up to the A&P mechanic. There are many airplanes out there in which replacing a side window is a simple task. However, be careful. As the aircraft systems become more complicated, so will the side window installation.
- Replacing safety belts. You are allowed to replace your seat belts and shoulder harnesses with approved belts for your make and model airplane. If you elect to change the belts it is strongly suggested that you follow the service manual instructions for installation. If the manual calls for two washers and a spacer, use them. Changing the belts is definitely a safety-of-flight issue, which may affect your well being.
- Replacing seats or seat parts with replacement parts approved for the aircraft, not involving disassembly of any primary structure or operating system. Once again, this should be regarded as a safety-of-flight issue that can affect your well-being. The seats are specifically designed. Don't modify them to make them stronger or more rigid. Replacement seats or seat parts must be of an approved design for your make and model airplane.
- Trouble shooting and repairing broken circuits in landing light wiring circuits. This doesn't include position and panel lights or similar lighting systems on your airplane. If you elect to venture into other systems, words of caution: Lack of knowledge of the system may cost you more money for needed repairs.
- Replacing bulbs, reflectors, and lenses of position and landing lights. Replacement is allowed in these two systems.
- Replacing wheels and skis where no weight and balance computation is involved. Enough said.
- Replacing any cowling not requiring removal of the propeller or disconnection of flight controls. Pilots are permitted to remove and replace cowlings and cowl flaps on the aircraft they own or operate. However, don't forget that only certified mechanics may remove a propeller.
- Replacing or cleaning spark plugs and setting of spark plug gap clearance. Some important items to consider when changing spark plugs: Have available and use the proper manuals, tools, and equipment needed for the job, which includes a torque wrench. Use the proper spark plugs for the engine. Know the plug rotation sequence for the engine. Many people use a simple process of rotating the plugs from top to bottom and then next in firing order.
- Replacing any hose connection except hydraulic connections. Owners are allowed to replace any hose or hose connection except hydraulic connections, which also includes broken lines. You are also allowed to change such lines as:
Cabin air hoses;
Carburetor heat hoses;
Cooling air hoses for radios.
Owners may replace static pressure lines except when used for IFR flight (see FAR 91.411); however, it is strongly suggested that you leave those to the A&P mechanic.
- Replacing prefabricated fuel lines. You are allowed to replace prefabricated fuel lines with approved prefabricated fuel lines for your make and model airplane.
- Cleaning or replacing fuel and oil strainers or filter elements. Follow the service manual instructions when cleaning or replacing fuel, oil, induction air, and vacuum filter elements. Use only approved strainers and filters when replacing them. The one from the automobile parts store is not approved.
There are several ADs that come to mind when talking about filter changes. You should also check with your mechanic for all ADs that apply to your airplane. AD 84-26-02 requires replacement of the paper induction filter prior to reaching 500 hours time in service. You are allowed to change the filter, but only an A&P can sign off the AD and return the airplane to service. Another AD that comes to mind is Avco Lycoming AD 80-04-03 R2, which requires at the next engine oil change, not to exceed 50 hours, adding an additive to the engine oil, examination of the engine oil suction screen for presence of metal particles, and the inspection of the external full-flow oil filter for metal particles by cutting it open so that the pleated element can be unfolded and examined. You can change the oil and make your entry in the logbook, but once again, only an A&P mechanic can return the airplane to service by signing off the AD.
- Replacing and servicing batteries. When replacing your airplane's battery, use only an approved battery for your make and model airplane. You are also permitted to add water (distilled water) and charge your battery. If you need to clean the battery, terminals, or battery box area, baking soda works about the best. Flush with fresh water when you're completed. Don't allow any baking soda to enter the battery.
Emergency Locator Transmitter battery replacement is also permitted, provided you are able to follow the manufacturer's recommendations. Don't forget that the new expiration date for replacing (or recharging) the battery must be legibly marked on the outside of the transmitter and entered in the aircraft maintenance record.
- Cleaning of balloon burner pilot and main nozzles in accordance with the balloon manufacturer's instructions. Comply with manufacturer's recommendations.
- Replacement or adjustment of nonstructural standard fasteners incidental to operations. You are permitted to remove and replace nonstructural standard fasteners, which also includes the removal and replacement of screws or rivets used to attach fasteners. Remember that you must use the approved fasteners, screws, and rivets for your airplane. If you are one of those mechanically gifted people, have at it: drive those rivets. But if you like to put a square peg in a round hole, this may be a complex task for you. Leave it to the professionals.
- The interchange of balloon baskets and burners on envelopes when the basket or burner is designated as interchangeable in the balloon type certificate data and the baskets and burners are specifically designed for quick removal and installation. You must comply with type certificate data sheet.
- The installations of anti-misfueling devices to reduce the diameter of fuel tank filler openings provided the specific device has been made a part of the aircraft type certificate data by the aircraft manufacturer, the aircraft manufacturer has provided FAA-approved instructions for installation of the specific device, and installation does not involve the disassembly of the existing tank filler opening. Always comply with the FAA-approved instructions from the manufacturer when installing anti-misfueling devices on your airplane.
- Removing, checking, and replacing magnetic chip detectors. Comply with the engine and airframe manufacturers' recommendations when removing, checking, and replacing the magnetic chip detector.
- The inspection and maintenance tasks prescribed and specifically identified as preventive maintenance in a primary category aircraft type certificate or supplemental type certificate holder's approved special inspection and preventive maintenance program when accomplished on a primary category aircraft provided:
- They are performed by the holder of at least a private pilot certificate issued under part 61 who is the registered owner (including co-owners) of the affected aircraft and who holds a certificate of competency for the affected aircraft (1) issued by a school approved under 147.21(e) of this chapter; (2) issued by the holder of the production certificate for that primary category aircraft that has a special training program approved under 21.24 of this subchapter; or (3) issued by another entity that has a course approved by the Administrator; and
- The inspections and maintenance tasks are performed in accordance with instructions contained by the special inspection and preventive maintenance program approved as part of the aircraft's type design or supplemental type design.
- Removing and replacing self-contained, front instrument panel-mounted navigation and communication devices that employ tray-mounted connectors that connect the unit when the unit is installed into the instrument panel, (excluding automatic flight control systems, transponders, and microwave frequency distance measuring equipment (DME). The approved unit must be designed to be readily and repeatedly removed and replaced, and pertinent instructions must be provided. Prior to the unit's intended use, an operational check must be performed in accordance with the applicable sections of part 91.
- 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.
AC No: 43-12A
Initiated by: AWS-340
- PURPOSE. This advisory circular (AC) provides information concerning preventive maintenance, who may perform it, the standards of performance applicable to it, authority for approving aircraft for return to service, and the applicable recording requirements. This AC also clarifies those areas most frequently misunderstood in the past, and explains the recent changes in the rules concerning preventive maintenance.
- CANCELLATION. AC 43-12, Preventive Maintenance, dated July 16, 1976, is canceled.
- RELATED FEDERAL AVIATION REGULATIONS (FAR). Part 1, Definitions and Abbreviations, Section 1.1; Part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration; Part 61, Certification: Pilots and Flight Instructors; and Part 145, Repair Stations.
- PREVENTIVE MAINTENANCE.
- The holders of mechanic and repairman certificates, persons working under the supervision of these mechanics and repairmen, repair stations certificated under Part 145, and air carriers certificated under Parts 121, 127, and 135, are authorized to perform preventive maintenance. These persons are also authorized to perform other maintenance. Therefore, it is of little consequence to them how a particular function is classified, since they are authorized to perform the function as either preventive maintenance or as other maintenance. Further, the procedures used in approving for return to service and recording are identical. This AC will, therefore, consider preventive maintenance from the owners/operators point of view.
- FAR Part 1, Section 1.1, defines preventive maintenance as ".... simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations."
- FAR Part 43, Appendix A, paragraph (c) contains the list of those functions determined by the FAA to meet this definition. If a function does not appear in this list, it is not preventive maintenance. Further, because of differences in aircraft, a function may be preventive maintenance on one aircraft and not on another. To provide for this, paragraph (c) contains the limitation, 'provided it does not involve complex assembly operations' on the aircraft involved. Owners and pilots must use good judgment in determining that a specific function may appropriately be classified as preventive maintenance.
- A pilot may not perform preventive maintenance on aircraft used under Parts 121, 127, or 135, even when the pilot owns the aircraft.
- Persons authorized to perform preventive maintenance. In addition to those persons listed in paragraph 4a of this AC, Section 43.3(g) authorizes the holder of a pilot certificate issued under Part 61 to perform preventive maintenance. Section 43.7 limits the privileges to persons holding at least a private pilot certificate and Section 43.5 prohibits operation of the aircraft unless approved for return to service. Further, pilots may only approve for return to service preventive maintenance which they themselves have accomplished.
- Applicable performance standards.
- FAR 43.13 requires preventive maintenance to be done using methods, techniques, and practices acceptable to the Administrator. These are normally set forth in the manufacturer's maintenance manuals; however, some may be found in ACs published by the FAA. [NOTE: It is absolutely essential to have the appropriate manuals and data when performing preventive maintenance.]
- FAR 43.13 requires the use of the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. This means that the proper tools and test apparatus must be used. Normally these are listed as part of any FAA-approved manufacturer's maintenance literature.
- FAR 43.13 also requires that any special equipment recommended by the manufacturer or its equivalent must be used in a manner acceptable to the Administrator. This provision is more directly applicable to maintenance than preventive maintenance. However, it may come into play. Therefore, owners and pilots should be aware of it.
- Additionally, Section 43.13 requires that the work performed and the materials used are to be such as to ensure that, when the work is finished, the item worked on is at least equal to its original condition. Caution must be exercised because some functions, which appear to be simple tasks, may, in fact, be quite complicated. Care should be taken to ensure that the manufacturer's instructions are understood, the function is within the individual's capability, within the definition of preventive maintenance, and that it is listed in paragraph (c) of Appendix A of Part 43.
- Recording preventive maintenance. Preventive maintenance must be recorded in accordance with Section 43.9 of FAR Part 43. This is done by entering in the maintenance record, of the item worked on, the following:
- A description (or reference to data acceptable to the Administrator) of the work performed." This should indicate what was done and how it was done. This is normally quite simple for preventive maintenance; however, if the description is extensive, reference to documents containing that description is acceptable. These may be manufacturer's manuals, ACs, or other documents or references containing data acceptable to the Administrator. If documents other than types which are in common use are referenced, the document should be made a part of the maintenance record, as required by Section 43.9(a)(1).
- "The date of completion of the work performed." This is self-explanatory and is the date on which the entry is made, as required by Section 43.9 (a)(2).
- The kind of airman certificate exercised. When preventive maintenance is performed as authorized in Section 43.3(g), the certificate may be indicated in any manner which would be clear to the reader. For example: PP, CP, or ATP might be used to indicate private, commercial, or airline transport pilot, respectively. The certificate number is that number displayed on the certificate being exercised. Affixing a signature to the entry, which describes the work accomplished, constitutes approval for return to service, as required by Section 43.9(a)(4). NOTE: Since owners/pilots are not authorized to approve work accomplished by others, Section 43.9(a)(3) is not applicable when preventive maintenance is performed by the holder of a pilot's certificate. The holder of the pilot's certificate doing the work is the only person who can sign the approval for return to service.
- The changes to Section 43.9 which require preventive maintenance to be recorded became effective October 15, 1982 (Amendment 43-23, 47 FR 41076; September 16, 1982). On this same date, the list of items considered to be preventive maintenance in Appendix A of Part 43 was expanded. Two of the items warrant discussion.
- Item 25 (Part 43, Appendix A, paragraph [c]. This item deals with the assembly of gliders and has been on the list of preventive maintenance for some time. The recording requirements are intended to provide continuity in the maintenance record and to ensure that the person performing preventive maintenance assumes responsibility for the work performed. An entry for the assembly after required inspection ensures this assumption of responsibility. Repeated entries are required each time a person assembles the aircraft for operation. The assembly must be recorded and the aircraft approved for return to service in accordance with Section 43.9 by a person authorized in Section 43.7.
- Item 28 (Part 43, Appendix A, paragraph (c)). This item deals with the installation of balloon baskets and burners specifically designed for quick removal and installation. Such disassembly and assembly is necessary to facilitate transporting the balloon either to the launch site or after a flight is terminated. The assembly operation is preventive maintenance and subject to the provisions of Sections 43.3, 43.7, and 43.9. As required by Section 43.1(b), entries are required for assembly operations on all balloons except those certificated in the experimental category which have not been previously certificated in another category.
- Items 6 and 23 (Part 43, Appendix A, paragraph (c)). These items permit the draining and reservicing of oil, and the removal, cleaning and reinstallation of oil screens, filters, and strainers in an aircraft oil system to be done as preventive maintenance, and are subject to the provisions of Sections 43.13(a) and (b).
Sections of FAR Part 43 are listed here to assist you in answering questions.
Â§43.3, Persons authorized to perform maintenance, preventive maintenance, rebuilding, and alterations.
Â§43.5, Approval for return to service after maintenance, preventive maintenance, rebuilding, or alteration.
Â§43.7, Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or component parts for return to service after maintenance, preventive maintenance, rebuilding, or alteration.
Â§43.9, Content, form, and disposition of maintenance, preventive maintenance, rebuilding, and alteration records (except inspections performed in accordance with part 91, part 123, part 125, Â§135.411(a)(1), and Â§135.419 of this chapter).
Â§43.12, Maintenance records: Falsification, reproduction, or alteration.
Â§43.13, Performance rules (general).
Â§43.17, Maintenance, preventive maintenance, and alterations performed on U.S. aeronautical products by certain Canadian persons.
Sample Preventive Maintenance Entry
(DATE) Total time__________hours. Landing bulb removed in accordance with (manufacturer) maintenance manual, Chapter___________, page________. Landing light switch placarded inoperative.
|___________________ ||____________________ ||_____________________ |
|Pilot's Signature ||Rating ||Certificate Number |
Sample Maintenance Entry (FAR 43.9)
(DATE) Total time ___________ hours. Aircraft heater and control switch deactivated by capping heater fuel lines in accordance with (manufacturer) maintenance manual, Chapter__________, page_________. Heater control switch placarded inoperative.
|__________________________________ ||____________________ |
|Mechanic's signature ||Certificate Number |
Updated Thursday, January 04, 2007 9:39:01 AM