Guest Blog: Why Aircraft Engines Should Be Hard To Start

Seriously, aircraft engines should be hard to start. Personally, I find the start—quick and easy, or filled with frustration—is an indicator of how the flight is going to go. It’s also a visceral experience of animating what had been, only moments before, a lifeless hunk of metal.

Think about it. You’re walking out to the airplane with the fuel-injected Continental or Lycoming sitting on a hot ramp. It has been a 30-minute turn, so just enough time for it to be well and truly heat soaked and you think this should be interesting. Instead you give it just the right amount of prime so it starts after the prop has barely made one turn and then when it treacherously tries to die, you catch it with the shot of prime (Continental) or the quick out and back of the mixture (Lycoming) and it settles down to a purring idle. You probably gave yourself a mental high five, thought “damn I’m good” and had a better flight than you expected.

Or, and this is for those who pull a J-3/Champ/T-Cart out of the hanger on a cold damp day and give it that two-and-three-quarters shots of prime you know this particular engine likes, flip a few blades through, add another half shot and then with one casual swing of your arm the engine roars to life. When the sad day comes that starting the engine on every airplane requires about the same personal engagement as turning on the porch light, aviation will have lost something undefinable but in my opinion, important.

All pilots have an engine start story. Mine was more than 20 years ago, but still vivid. I had the opportunity for two glorious summers to be a copilot on a Douglas DC-6 fire bomber. After my initial training, I was paired with the senior captain in the company, a man who had more than 20 years of experience on the mighty Douglas and was definitely on the crusty, old-school end of the pilot spectrum. On our first day on contract, we were going to fly the airplane to our operating base. 

The first issue for me was that the airplane had just landed after a final maintenance test flight, which meant the engines were hot. The Pratt & Whitney R-2800s could be a challenge to start when hot as they flooded easily. Too much prime and they would not fire or fire just enough to start a stack fire. Too little prime and you got a big backfire from the too-lean mixture. The second issue was that the captain had made it clear as we were setting up for the start that a bad start would reflect poorly on him, a situation that was simply impossible for him to contemplate. The third issue was the first engine to be started was Number 2. I started the engines on the left wing and the captain started the engines on the right wing. The captain informed me with just a hint of malicious glee that Number 2 on this particular airplane was known to be especially cantankerous when hot.

So it was showtime. The captain gives the start signal to the ground crew, calls clear and I squeeze the start toggle, the middle one between the boost and prime toggles. The starter makes a deep harsh grinding noise overlaid by the clunking of all the many moving engine pieces.  The skipper calls the blade count: three, six, nine, twelve, and then switches on the mags, which is my cue to get on the boost and prime and … nothing. Flooded I think, so I get off the prime, more grinding and just when I am getting worried that it’s now too lean, a cylinder fires closely followed by the ragged blast of the other cylinders starting to fire as the engine picks up speed, back on the primer. And then it starts to die. Too much prime I guess so I start tickling the prime off and on, the engine starts to pick up again and now I can leave full prime on and call for the mixture to be moved from idle cut-off to auto-lean. As the mixture comes in, I can get off the prime and the boost and adjust the throttle for 1000 RPM. The captain looks at me expressionless but can’t help having his lips curl into an involuntary small smile at a test passed and the start of a good flight.

Nowadays, the captain of a modern-day transport category aircraft barely has to interrupt his Brady vs. Belichick rant in order to press the button marked “start,” secure in the knowledge the computer magic will look after the start with no pilot input needed or desired. I am pretty sure in 20 years, no one will remember that start.

I firmly believe that airplanes have a sense of humor, it’s just really cruel. I also believe that airplanes talk to their pilots. Sometimes it’s obvious like the squealing tire saying, “Get off the brakes you moron!” Other times it’s more subtle. On the last start of my airplane with less than ideal conditions, I am sure the engine sub vocalized, “Do you feel lucky, punk?” My response was a full-throated “Hell yeah, bring it on. You are mine today.” The start went just fine.

So as I was told in basic training, embrace the suck. Don’t complain about engines being hard to start, just look on it as another way to master adversity on the way to a perfect flight.

David Gagliardi has been an instructor, banner tow pilot and air taxi pilot and has also flown forest-fire-suppression operations. He keeps up his instructor and aerobatic instructor ratings and also teaches formation flying as a FAST-rated 4 ship lead pilot. He currently works as a Transport Canada Flight Operations inspector based in British Columbia. The opinions expressed here do not necessarily reflect the views of Transport Canada or the government of Canada.