If you’re ever at the airport late at night, or early in the morning, you may have noticed that a lot of planes spend the night at the gates. Have you wondered why?
Usually they’re on what’s called a “remain overnight,” where they sit on the ground long enough to have some work done.
As a mechanic for a major airline, I’m responsible for taking care of planes on their overnights. In this article, I’ll walk you through an airplane’s typical overnight “service check.” It should be noted, though, that different types of planes have different personalities and so the service checks vary between types. Some are needy and require a seemingly endless number of tasks. Some are chatty and will tell us all sorts of stuff about themselves without being asked. Some are tall and aloof and make us work hard to inspect and service them.
When our assigned plane arrives, the first thing we do is add oil to the engines if needed. It’s a lot like adding oil to your car, except the oil costs about $20 per quart. We try not to spill.
Then it’s up to the flight deck to check the logbook for “inbounds,” which are problems written up by the flight crew. Often there’s nothing, but when there’s something it can be as simple as broken tray table or as complex as an electronics glitch in one of the engines.
Next is the “walkaround.” Starting at the nose, we look at the radome for dents. We look for evidence of birdstrikes or other foreign object damage. We check the engine-driven generators to make sure they have enough oil and their filters aren’t clogged.
We measure the tires and brakes to ensure there’s still enough wear left in them, and then inspect them for problems that could cause failure at takeoff or touchdown. We look at the wings, tail, and landing gear wells for hydraulic leaks. We check for the wicks that pass static electricity buildup harmlessly into the atmosphere. We make sure the cargo compartment walls are intact and that the lighting and nets are in good shape.
As we’re checking all these items, we’re also inspecting the airplane’s skin for any dents or damage and making sure the static and pitot probes are clear.
Once we’ve checked the outside we go back to the flight deck where we check the lights, inside and out, run a few electronic tests, and check hydraulic fluid levels. Finally, we make sure there’s paper for the printer, and that the windshields are clean. In the summer, they get very buggy.
In the passenger cabin, we verify the integrity of all the safety equipment and exit signs, lights and slides. We make sure the toilets flush and the water runs and that the anti-smoking/anti-fire components in the lavatory are present and working.
On an easy night, we check everything, it’s all good, and we sign it off. On a hard night, we find and fix tires and brakes that are worn past the limit, or birdstrike damage in an engine, or inbounds that require hours of troubleshooting and repairs.
Once we’re sure a plane is happy, it’s time to sign it off and put it to bed. We turn off the battery or batteries and turn off the main power bus to the airplane. The plane goes dark and settles in to sleep until the first flight of the morning.
Jennifer Lasher is an aircraft mechanic who volunteered on the Museum’s 747 restoration project.