Engineers design aircraft. Manufacturers build them. Pilots break them. Maintainers fix them.
At a retirement luncheon for a friend several months ago, a U.S. Air Force maintainer began discussing her role.
“I wouldn’t fly in any of the aircraft we maintain,” she said. “The complexity of the systems makes it difficult to know for certain that absolutely everything is correct.”
Maintainers play a critical role in aviation safety, but their work often doesn’t get the attention or support it deserves from regulators, engineers and manufacturers. While FAA is focused today on certifying new aircraft, this could be an opportunity to revisit standards and certification dealing with the maintenance of new and existing aircraft.
The Federal Air Regulations has 82,000 words and 125 pages devoted to the certification of pilots and instructors. Pilot certification is based upon levels of demonstrated experience, types of aircraft to be operated and levels of responsibility. There are seven levels of pilot certification, plus instructor licenses, across 10 types of aircraft — as well as specific ratings for aircraft deemed advanced and complex.
But when it comes to the section covering the certification of mechanics and repairmen, there are only about 4,000 words and six pages and just two certifications: airframe and/or powerplant, with further experience requirements for inspectors.
While pilot certifications have adapted to the multitude of technologies introduced over the last century, those for maintainers haven’t changed much since rotary engines and fabric wings. I exaggerate a bit, but the same powerplant mechanic license authorizes work on piston engines and turbojet engines. An airframe mechanic can be expected to know how to work on fabric, metal, composite and other materials, besides dealing with cables, push rods, hydraulics and fly-by-wire flight control systems. With new designs in the works — including hybrid-electric propulsion, high-energy-density batteries, advanced avionics and computer-aided systems, enhanced vision systems and much more — maintainers cannot simply depend upon their training and experience, but must instead rely on specific diagnostic and repair instructions from the manufacturers.
As engineers and manufacturers, how much thought do you give to the maintainability of your designs? Sure, line replaceable units (LRUs) are a simple and easy concept, but the operator needs to have a suitable supply of each of the LRUs at stations that may need them. And how easy is it for the line mechanic to diagnosis which LRU is the faulty piece of a complex system? Further, what about the repairman at the depot who will be tasked with diagnosing and repairing the LRU so it can be returned to service? All of this needs to be considered for simple plug-and-play components.
Major repairs at an MRO (maintenance, repair, and overhaul) facility are delegated to teams of maintainers who are very familiar with the aircraft type, and often to sub-teams specializing in specific components and systems. Why should a maintainer who works on airliners or jet aircraft need to be trained in piston engines or fabric and dope wings? Same for the line repairman at a commercial airport who is tasked with shortening the delay of an airliner departure. Over time, they will become familiar with the transport aircraft at that station and their recurring faults and failures.
A smaller shop at a general aviation airport may see dozens of different aircraft models each month with a multitude of different systems and construction technologies. These include even the occasional homebuilt aircraft that still need to be maintained to industry safety standards. Shouldn’t there be separate certifications for each type of powerplant or propulsion system? Couldn’t we simplify the aviation maintenance schools by allowing students to select what airframe materials or systems they want to be certified in, speeding entry to employment?
At the same time, engineers and designers must ensure that maintenance instructions are clear, concise and simple enough that any maintainer with a general understanding of the design can make the needed repair. This is true both for the original design philosophy of the aircraft concept and the readability of the language of the manuals. OEMs work with their production personnel when designing a new aircraft to ensure it can be efficiently produced, but there’s little conversation with downstream maintainers that could influence the details of their repair instructions and manuals.
A few years ago, I was tangentially involved with a new helicopter certification in the U.S. These EASA-certified aircraft were designed and manufactured in Europe. Aircraft for customers in the Americas were then transported by ship and checked out in the U.S. before receiving FAA certification and being delivered to customers. Customers became upset that their aircraft were delayed for many months because the French maintenance manuals (in which some parts were translated to French from German) were not accurately translated to the international aviation language of English. The rewrite and subsequent approvals to meet standards took months. I can only begin to imagine how a maintainer somewhere else in the world, who didn’t have French or English as their first language, would cope with the maintenance instructions for this complex machine.
Manuals are only getting more complicated as the systems become more complex. The maintenance manual just for the Garmin G500Txi instrument display in my Beechcraft Bonanza is 137 pages. The operator’s manual for my installed Garmin GTN 750Xi GPS system is 528 pages and the service manual is another 144.
Maintainers are the under-appreciated members of the aviation community. They don’t get the prestige of the pilots, the face time of the flight crews or the acknowledgement of the pressures faced by air traffic controllers. Yet they are every bit as crucial to the safety of the air traffic system. We must pay more attention to their needs and issues to not only reduce their frustrations with complicated systems, but to reward and acknowledge their skill and responsibility in aviation.
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