Early on the morning of December 17, 1903 at Kill Devil Hills near Kitty Hawk, NC, Orville and Wilbur Wright circled the soon-to-be-famous Wright Flyer. They checked the two 8-ft. wooden propellers for nicks, inspected the truss-and-wing warping wires for fraying, and looked for tears in the muslin fabric coverings on the wings. They then turned their attention to the security of the 12 HP engine they had helped develop, and examined the condition of the 60-ft. monorail launch track they would use to become airborne. Little did the two brothers know, they had just completed an activity that would become one of the most fundamental, basic operations of an industry that would change the world.
The “Preflight Inspection” is the first procedure students will learn on the road to becoming pilots, and they will continue to use it for the rest of their flying careers. It’s unique to aviation–we don’t preflight our cars, our trucks, or our motorcycles and the reason is obvious. However, I’m amazed at how such an important task is often overlooked or approached in a sloppy, haphazard fashion. In this discussion, I will not get into specifics of what to look for and what not to look for on a preflight inspection, other than to quote Pat Cox, Robinson’s former service manager, who would say during the maintenance portion of the Safety Course. “If it’s supposed to move, ensure it does; if it’s not supposed to move, ensure it doesn’t.”
Instead, I’d like to take the 30,000-ft. view. We fly in machines and machines will break. We fly these machines in an environment that’s not natural to us–we’re not birds. As soon as you think you have total control of your machine or your environment and allow complacency to seep in, this helicopter world will rise up and take a big bite out of your ass, the size of which you may not survive. So, I want to apply a more Zen-like approach to the “preflight.” To paraphrase the title of a Billy Joel song from the mid-70s, you have to be in a “Pilot State of Mind” [1] and the door to this state of mind is the preflight inspection. The preflight is the perfect opportunity to mentally transition from the normal, two-dimensional world we’re used to operating in, to this unnatural, three-dimensional world of flight. In this “Pilot State of Mind” the helicopter will speak to you, but you have to listen and it starts with the preflight. A fluid level that decreases, the increasing play in a bearing or, in flight, a change in noise or vibration are all examples of the helicopter tapping the pilot on the shoulder, alerting them of a potential issue. Don’t rush the preflight, avoid distractions, use a checklist, and as I said, “listen.”
I want to make an important comment about the use of a checklist during the preflight. Every evaluation standard (PTS & ACS) for every practical test from private pilot to airline transport pilot requires the use of a checklist for the preflight inspection. During my 27-year career as a US Army instructor pilot, every checkride I gave required the use of a preflight checklist. This is not just to show the ability to use the checklist, but, more importantly, to instill the importance of overcoming the common human mistake of “forgetting something.” I’ve been flying the Robinson R22 as long as anyone alive and have thousands of hours in it, but I’m human. I can sometimes miss something if I don’t review my checklist during or at the end of the inspection. If you are new to the make & model, I recommend a line-by-line use of the checklist, but as you get more familiar with the model, you can refer to the checklist after inspecting a section of the aircraft. I wish I had a dollar for every checkride I’ve given where at the start of the preflight I’ve had to say, “Are you forgetting anything?”
I’ll end this discussion with my favorite preflight story, which occurred early in my Vietnam experience. I had only been in-country a few weeks and was conducting a preflight inspection with Steve (Robbie) Robinson, my aircraft commander (AC) for the day’s mission. Some ACs directed the co-pilot to conduct the preflight, some insisted on doing it themselves and others, like Robbie, saw it as an opportunity to mentor the new pilots so both conducted the preflight. Robbie took one side of the UH-1 (Huey) and I took the other. As Robbie moved to the long tailboom section of the Huey, he rapped his knuckles indiscriminately along the bottom of the structure, like he was knocking on a door. I asked, “Robbie, what are you doing? That’s not on the checklist.” He answered with “Listen, Newbie, I use two checklists: one the Army gives me and one my experience gives me.” He explained that a number of months ago, he was preflighting a ship that had just come out of maintenance. The aircraft had been down for quite a while, waiting for some uncommon spare parts to arrive. To save space in the hangar, the maintenance people had detached the tailboom, placed it next to the fuselage and stored it outside covered with a tarp. During the preflight, Robbie just happened to tap the bottom of the tailboom and instead of the ringing sound expected from tapping sheet metal, he heard and felt a dull thud. To investigate further, he opened the right rear cowling for the “oil cooling fan and heater” compartment. In Vietnam we didn’t have heaters in the aircraft, so there wasn’t much in there except you could stick your head in and look down the interior of the 15-ft.-long tailboom. Robbie took the flashlight from his survival vest and shined it down the length of the tailboom. About halfway down the tailboom, the light caught a curled up 12-ft. Burmese Python as it rose into a striking position poised to attack. Robbie dropped the light and smashed his head on a support strut, trying to withdraw from the compartment. It took the maintenance people two full days to coax the snake out of the tailboom. For the next 50+ years, I’ve done a modified tap-test along the tail section of every helicopter I’ve flown.
For additional information and specific preflight guidelines, I recommend the United States Helicopter Safety Team’s (USHST) Helicopter Safety Enhancement 28 (H-SE 28), Helicopter Preflight, Final Walk Around and Postflight Inspection Guidelines.
Tim Tucker
December 2024
[1] “New York State of Mind” released by Billy Joel in 1976