FAR Review

March 1, 2005
The rules we live and suffer by as mechanics.

March 2005

Sometimes we have to step back and take a look at the regulations that govern our work as certificated mechanics and see where we stand and how we think about the rules while we are working.

Subjects like approved for return to service, major or minor repair or alteration, experience requirements for mechanics, progressive inspection, checklist, approved maintenance manual, airworthy, inspection authority limits, work orders, ADs...these and many other less prominent items routinely come up during conversation with groups of mechanics and are fertile areas for disputes.

The basics

The Federal Aviation Regulations (FARs) that we mechanics frequently refer to are located in Title 14 of the Code of Federal Regulations at Part 43. These rules simply set forth the basic standards for general maintenance, and preventive maintenance, rebuilding and altering aircraft and their subparts and accessories.

Part 65, Subparts D and E, are the requirements for certification of mechanics and repairmen.

Part 91 Subpart C sets out aircraft owners' responsibilities for maintenance of the aircraft and any preventive maintenance or alterations. Some of the Part 91 sections contain similar record-keeping requirements as are found in Part 43.

If you are going to get in trouble it will be involved with the performance rules of maintenance, preventive maintenance, or alterations (Part 43.13). In addition, there are other rules for inspections contained in Part 43.15.

Work orders are not required by the FAR, however, contract law applies in these situations and all of your maintenance agreements should be in writing and signed by the customer. The order should clearly spell out the scope of the work to be performed. Certain boiler-plate disclaimers should be preprinted on the form to limit your liability in case of the failure of parts supplied. Forms should be reviewed by counsel to assure that they comply with this important area.


Everybody in this business should know by now that we are a nation of whiners and you can be sued for just about anything. The airplane maintenance business is no exception. If the person suing you (or the FAA) can prove that you violated one of the FARs in performing maintenance on an aircraft their job is easier. Violation of a FAR will generally find you negligent as a matter of law in any lawsuit. Negligence is simply defined as the failure to use due care or reasonable care in the performance of your work. Keep in mind however that even though you do follow the FARs it does not necessarily mean that you used due care for the job. Your duty of care in performance of the work is often measured by the requirements of the FARs.

Case in point

Here's an example. Recently I had a call from a mechanic who said a lawyer for an insurance company was threatening him to collect what they paid out for the repair of an aircraft that had made a gear up landing. He said that the mechanic had performed an annual inspection a month before the accident. There were no injuries, only property damage. On examination of the aircraft it was alleged that the left main wheel had come off the axle because the cotter pin securing the nut was missing from the wheel nut. The nut and the cotter pin were not found. Ten hours of flight time and a little over a month had passed since the annual inspection. They said that the pin on the right hand wheel nut was missing but the nut was still in place.

The FAA had investigated this accident and spoke with the mechanic and the owner about the details. The mechanic maintained that it would have been impossible for him to have missed the cotter pins during his inspection. He maintained that someone else must have been involved. Note the problem here. The FAA would have some difficulty in placing the blame on the mechanic because of the passage of time since the annual was performed. As one authority has frequently stated...your liability for an annual inspection ends when the ink dries on the paperwork.

The FAA disposed of the case with a warning letter to the mechanic. This was significant, because there was no finding of a violation of any performance FAR and therefore, in any civil case, no finding of negligence as a matter of law. This would make a lawsuit by the injured party difficult, but not impossible, to prove. The fact that the case will be more difficult means that they could lose, and be out more money for legal fees. Remember, in this case it is the insurance company that is suing in the name of the insured in order to get their money back. Assessment of the threat of loss is always a consideration. They don't like to take chances and wind up paying out more in attorney fees than they can expect to recover by way of a judgment.

Since in this case there was no insurance for the mechanic there would probably be no lawsuit because of his possible use of bankruptcy proceedings to dispose of any judgment that might be lodged against him. Lawyers and insurance companies always like to find insurance because it secures their payment, assuming they win the case.

AD compliance

There is no specific FAR reference that says a mechanic must ensure that the aircraft conforms to any applicable airworthiness directives. FAR 43.11b requires, on the other hand, that when you find the aircraft is not airworthy during an annual or other inspection you must give the owner a list of the discrepancies, including all airworthiness directives that are not met. AC 39-7a suggests that when you inspect you must determine whether all airworthiness requirements are met and this includes airworthiness directives. It could be argued that a failure to discover and ensure all ADs are complied with is a violation of the FARs.

Return to service

A certified mechanic with the appropriate rating may approve an aircraft or part for return to service after a minor repair or alteration. However, only a mechanic with Inspection Authorization may approve an aircraft or part for return to service after a major alteration or repair. Part 43, Appendix A lists what is a major alteration or repair.

Rebuilt vs. overhauled

Whether an aircraft, engine, or other part is rebuilt or overhauled has always been a point of argument and discussion. FAA provides FAR 43.2b.

"No aircraft or aircraft part may be described as rebuilt unless the aircraft or aircraft part is disassembled, cleaned, inspected, repaired as necessary, reassembled, and all parts used in the rebuilt aircraft (or engine) conform to new limits."

Maintenance records

FAR 43.9 contains the requirements for content, form, and disposition of maintenance, preventive maintenance, rebuilding, and alteration records. The record must include a description of the work performed, and the date it is completed. In addition, the mechanic approving the repair, must sign the entry and include his certificate number and type of certificate. Shop maintenance records are required to be retained for two years. AC 43-9b set out a detailed treatment of both Part 43 and Part 91 record requirements.

Part 91 prohibits the operation of any aircraft that has undergone maintenance, preventive maintenance, rebuilding, or alteration unless it has been approved for return to service by a person authorized under Part 43 to perform the service and the entry required by Part 43 has been made.

Many owners don't understand that it is their duty to keep their aircraft in an airworthy condition. They sometimes express the thought that they feel that their mechanic is responsible for the aircraft condition. You should set them straight whenever the subject comes up and direct them to read the relevant sections of Part 91.

There have been some FAA attempts to assess penalties against a mechanic or maintenance facility where a customer takes his aircraft from the shop without permission and has an accident. The FARs support the mechanic. The owner or operator cannot shift the blame for an accident to a shop or mechanic by simply stating that the aircraft was released prematurely. One of the key protections for the mechanic or any shop, in this area, is to avoid releasing logbooks (maintenance records) with any approval for return to service until all bills are paid and they are satisfied with the work. Logs (records) should always be kept in a locked safe in your office and only released to the owner when the transaction is complete.

Keep in mind that your records will be pawed over by the FAA and lawyers if any litigation should result from your work. Also, mere compliance with the FARs and complete maintenance records will not by themselves ensure insulation from liability in any accident case, but...it will definitely support your argument that you used a good standard of care in your work.

Also be aware that the FARs are always subject to various interpretations and they overlap in many areas. The violation of any FAR is always subject to argument and you must rely on civil case decisions, NTSB decisions, and various other sources, including your lawyer, to support your position. Please direct any questions or comments to .