Last time, we highlighted many of the cockpit tasks airline pilots perform prior to each departure. In this post, we’ll head outside the airplane to examine the external aircraft walkaround. This preflight procedure is equally important to all pre-takeoff cockpit checks and is a mandatory part of each flight leg. Through the walkaround, pilots are able to further enhance the safety and comfort of their passengers.
Why the Walkaround?
Throughout the aviation industry, safety is the paramount concern. Much of the airline industry’s stellar safety record is achieved through minimizing/eliminating foreseeable risks. The external aircraft preflight is a highly effective method of risk minimization. Unlike with ground-bound modes of transport, aviators can’t just pull over to the side of the road in the event a mechanical issue arises. For this reason, a detailed examination of the aircraft’s structure and systems is necessary to reduce the chances of an in-flight malfunction.
Tires and Landing Gear
Though used for only a fraction of each flight, the landing gear system is a vitally important safety component. Think about it: airliners are multi-ton monoliths larger than most houses. Additionally, even at their relatively slow approach speeds, they’re still travelling faster than anyone outside of the NASCAR circuit ever drives. The stress of several landings a day means the landing gear and tires have to be ridiculously tough to handle those weights and speeds. A malfunction here could make for a very memorable landing.
On the walkaround, pilots observe such factors as the tread, inflation, and wear of the tires. They’ll also examine gear struts, hydraulic lines, brake components, nuts/bolts/fasteners, and anything else noteworthy for their model. Anything appearing out of the ordinary will be addressed before the crew will consider departure.
As you’ve probably guessed, the powerplant is the heart of the plane. Without fully functioning engines, a state-of-the-art airliner becomes a very expensive glider. To avoid this undesirable possibility; pilots look for leaks, signs of scorching, evidence of foreign object damage (FOD), worn/overstressed components, and anything else that appears irregular. In some cases, maintenance personnel assist with the inspection, due in part to the engines’ often-unreachable height. These external inspections are then cross-referenced with cockpit indications to ensure full engine functionality. In case you’re wondering; all commercial aircraft are rigorously tested and certified capable of taking off, flying, and landing with an inoperable engine. Should an unlikely engine failure occur, the other engine(s) are capable of sustaining flight.
Despite their massive size, at times airliners can be difficult to see; especially under low visibility conditions and at night. In these instances, external lights go a long way towards helping the aircraft show up. Navigation lights and anti-collision lights are among the most common lights used to make the aircraft stand out. On the walkaround, pilots check to ensure these required lights are operational.
Additionally, at night and during low visibility conditions, external lights greatly assist the pilots in seeing the airport environment. Landing lights and taxi lights are the most common lights that aid in seeing outside the aircraft. For winter weather, some planes have ice lights, which assist the crew in detecting ice accumulation on the wings. Pilots verify proper operation of these external lights when conducting the exterior preflight.
Throughout the walkaround, the pilots inspect the various sections of the airframe. From nose to tail, they look at the fuselage, wings, and empennage for any indication of damage or defects. Depending on the airplane model, other items that might be scrutinized include: flaps, spoilers, ailerons, static wicks, static ports, pitot tubes, antennas, radar pods, pneumatic deice boots, and countless other model-specific parts. Any components appearing suspect are further evaluated to ensure safe operation.
The demanding environment in which airliners operate requires all systems to perform flawlessly. An external preflight inspection helps pilots detect possible deficiencies and minimize the chance of malfunctions aloft. Through their preflight walkarounds, pilots are able to reduce risk and enhance the safety of their passengers.