The pilot is ultimately responsible for passenger safety. But how can he be sure of the aircraft and its maintenance if he’s not a mechanic?

I am often asked if I feel comfortable with the quality of the maintenance on the aircraft I fly (answer: yes), and if I can tell whether maintenance has been done properly (answer: sometimes). I am certainly not a mechanic, but I do have a basic working knowledge of mechanical operations.

Pilots must follow a rigorous set of procedures to ensure that our aircraft meets all FAA specifications required to fly the plane legally and safely. You’ve probably heard a pilot announce, “A maintenance item has been fixed, but we’ll have to wait for the paperwork to be finished.” This paperwork is crucial in complying with the legalities of releasing an aircraft for flight. By signing off on the maintenance document, the mechanic certifies that the item has been repaired according to established procedures. This legally confirms for the pilot that the mechanic has completed the repair satisfactorily. We must trust the professionals who maintain these complex machines, as well as respect their dedication to doing their job by the book.

The recent maintenance fiasco at American Airlines over failed FAA inspections of MD-80s has served as a wake-up call not only for the carrier, but for the entire airline industry. The exemplary safety record of U.S. and Canadian airlines can be attributed to superbly built aircraft, extensive maintenance procedures and a group of professional mechanics, pilots, controllers and FAA administrators who take their jobs very seriously. But as in most activities involving people, human error can creep into the equation over time, requiring continuous attention to keep accidentsfrom happening. In American’s case, it turned out that some attach points for wire bundles in the main landing gear wheel wells were not spaced properly, which led to the grounding of the fleet of aircraft.

Maintenance discrepancies exist, in part, because inspection requirements change frequently. These changes may result from newer aircraft parts becoming available, recently discovered faults with already installed parts, or unexpected wear on aircraft parts. This wear and tear comes primarily from the rapidly changing environments in which airplanes operate, which cause continual stress and strain on aircraft structures and systems.

Say your flight takes off from Miami on a hot, humid December day, then flies to Chicago, where a blizzard is blowing at subzero temperatures. The various metal and nonmetal components of the aircraft react differently to changes in atmosphere, temperature and load factor (turbulence). The constant expansion and contraction of the various components impact systems variously over time, and will cause some elements to wear excessively and possibly fail. When discovered, these component failures force the publication of a fleet-wide bulletin either from the FAA or the plane manufacturer, requiring a change in the way a particular maintenance procedure is carried out. Some maintenance procedures change so dramatically that a formerly simple fix becomes an extremely complicated process.

These continually morphing administrative requirements affect all airlines and necessitate constant attention to detail. In most cases, carriers display disciplined adherence to established procedures, keeping our exemplary safety record clean. In an industry where compliance to maintenance procedures is so restrictive, there is no wiggle room. While thousands of passengers were affected by American’s recent flight cancellations, most of them also expressed relief that there had been no accidents, and they admitted that the inconvenience was probably for the best.

Multiple redundancies are designed into aircraft systems for safety reasons. The aircraft I currently fly has four engines and four separate systems for its hydraulics, pneumatics, electrical and many other component systems. It is comforting to know that we have three backups for each system on the plane, since we fly over thousands of miles of open ocean—often at night—with the nearest landing field hours away.

Pilots have considerable influence over safety and maintenance. We are required to complete a “walkaround” before each originating flight of the day. This gives us a good opportunity to look for any last-minute problems with the plane’s exterior surfaces before takeoff. While we rarely find any discrepancies, the walkaround may reveal impediments to the safe operation of the aircraft. During one walkaround, I found a four-inch-long bolt embedded in a tire, which resulted in the tire’s replacement prior to departure. This bolt could have caused any number of problems, from deflating the tire to being spun out at high speed and possibly puncturing a fuel tank or a hydraulic line.

We all remember the Air France Concorde crash of July 2000. The aftermath investigation revealed that debris from a previously departed aircraft had fallen to the runway, where it was hit by the Air France jet. The debris punctured a tire, throwing heavy bits of rubber that ruptured a fuel tank and caused an uncontrollable fire, resulting in the crash. In the end, human error was deemed a contributing factor in the horrible accident.

Teamwork is also a key factor in maintaining a superb safety record. Thanks to professionals throughout the airline industry, pilots can take pride in our accomplishments—but we must also remain vigilant in order to thwart complacency in the complex, unforgiving environment of commercial aviation.

Safety’s human element

The fatal crash of the Air France Concorde in 2000 was a tragedy, but it was also a rarity: Consider how many other accidents pilots have managed to avoid because of strict safety procedures and the countless hours we spend training in simulators. Today’s outstanding airline safety record depends heavily on the training pilots undergo. Modern flight simulators can replicate almost any adverse flight condition, from failed mechanics to disruptive weather. Pilots cannot pass our “check ride” (the equivalent of a driving test) until we’ve mastered myriad flight scenarios, often under the most demanding conditions.

For a four-engine plane like the one I fly, this mastery means flying an approach with two engines out (on the same wing) in very poor weather, in addition to many other difficult situations. Needless to say, it is a real challenge and a valuable learning experience.
_____________________________________________________

CHRIS COOKE is a pilot with a major domestic carrier. He can be reached at editor@executivetravelmag.com.