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.

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  1. Success starting a somewhat cantankerous air starter equipped eastern bloc radial does provide a Walter Mitty moment flashback to Jimmy Stewart’s heroic start of the Phoenix…as well as the public opportunity for peer reviewed failure.

  2. Years ago I flew a Warrior that if one used the POH to the letter, one would kill the battery before it would start. My instructor showed me a different way to start it. Upon using his technique, I could now get that slug to fire on one turn of the propeller. Faster than any fuel injection plane would. Nice to know. Even hot it would fire up.

  3. Yes, we all have our “hard to start” moments and our “tricks of the trade” for easy starting. But that doesn’t make this a good article. Personally I think our GA aircraft engines should be as easy to start as car engines now are, as well as have many of the now-standard features of car engines. GA engines are so far behind that it’s ridiculous.

  4. My first airplane had an A-75 Continental with no electrical system so you had to hand prop it. If you flooded it, per the manual, you needed to turn the prop backwards several times to “evacuate the cylinders” before trying again and sometimes that worked fine. Sometimes it didn’t and in that case I learned the best thing to do was just take a break (hand propping a flooded engine can be very frustrating), walk away from it, and find something else to do for about 20 minutes, and then try again. That always worked.

  5. While I love these old stories, I totally disagree. Application of modern tech would make flying more confidence inspiring as well as convenient. The basic LyCon design is great and wouldn’t be out performed by auto conversions BUT they could be transformed with auto technology. Combustion chamber design copied from any current pushrod V8, direct fuel injection and electronic ignition, run 11:1 compression and you could delete the starter and associated weight entirely. With 4 or more cylinders the computer just chooses the cylinder on the power stroke, spritzes a shot of fuel in the combustion chamber and lights the fire then magically the engine is running. Huge efficiency gains, substantial power increase and meaningful weight reduction! BUT with the FAA and subsequent “Business Case” it ain’t never gonna happen and I’ll have to keep using Voodoo to start the Continentals in the T-41s in CO Springs.

    • Thomas, I’m 100% with you on this. I appreciate nostalgia as much as anyone, but we are many decades past the point where i derive anything but annoyance at having to time that judicious shot of boost pump to the millisecond just to ensure my IO-520 doesn’t die and force me to do the entire ritual all over.

    • Every advanced item on an engine brings with it more complexity and more points of serious failure. Personally I find “confidence” in the fact that my arcane engine will keep running even if I have a complete electrical failure, a fuel pump failure, and lose a mag on the same flight.

  6. Back in my young Air Force days we had a power unit, the MD-3, that was powered by a modified Continental O-360 engine. I found that by treating it like an aircraft engine, usually made it easy to start. Throttle cracked, engage the starter, and a quick shot of choke or 2 and it would go. I took great pleasure in starting that unit reliably, especially after an aircrew member tried and failed.

  7. Whimsical article, I guess. It’s the 21st century folks. Continental’s and Lycoming’s inability or unwillingness to FADEC their engines and pursue other tech improvements is a bit to comfy for them and holds back GA. It’s supported by a masochistic pilot community that thinks it’s cool to be nursing 1930’s tech.

    • Actually, it appears to be the average GA pilot’s inability or unwillingness to actually put money into a FADEC-controlled LyCon engine, since both manufacturers have at times attempted to build such an engine but apparently didn’t get enough demand for them. It’d be nice if they could just add on a bunch of electronic controls to an O-360 (for example) and sell it as a drop-in FADEC solution, but unfortunately we know that’s not that case.

    • I agree. Am a retired A&P and the first time I ran into a FADEC equipped aircraft years ago was at a flight school that had the Liberty XL which was so equipped. Remember using a laptop to diagnose the engine which I thought was kinda cool. Also, we had Cessna 150/152 aircraft which, if memory serves, had the Marvel Schebler carburetor that was designed back in the 1930’s. Way past time to modernize. If folks still want the old days then let them. For me the engine start shouldn’t be an ordeal. If cars were this difficult no one would drive them.

  8. Those people who long for a “modern” aircraft engine (I include myself here) need to replay Paul Bertorelli’s great video on the subject. The lack of such a machine is as much our faults as the manufacturers’. I had the good fortune to fly right seat in a Porsche Mooney many years ago. One thing about the experience that sticks in my mind was how easy it was to start, both cold and hot. That and the distinctive sound of a P-911 once it was running.

  9. “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.”

    I love this.

    One of the reasons I love planes, bicycles, motorcycles and V8 cars is that sense of connection and involvement.

    This is one of the very things that will be removed from us by being forced to adopt EV’s.

    ‘Better’ in some ways is not the same as ‘cooler’ in any way.

  10. I too flew the DC-6 as engineer and copilot, I never got comfortable starting those R-2800’s, explosions, flames, really tough when cold soaked on the DTW ramp, we always had a ramp guy standing by with a fire bottle until all four were going. I also flew the DC-7, a dream to start, fuel injected R-3350’s, a problematic engine, but sounded great at TO power.
    Note, number 2 was started first because it had one of the two hydraulic pumps, number three had the other one. I retired on the 777, just have a cup of coffee and watch it happen!

  11. I flew right seat on a DC-6 a few times in Alaska. Engineer did all the starts. All I did was count blades. Now as a 777 CA, I call for engine start and the FO turns the left and right start switches on, raises both fuel control switches to on, and we watch both engines start (-200). Easy!

  12. I’m an 8000+hour flight instructor and banner tow pilot and have started (and flown) most Cessnas, most Pipers, a Mooney, a Citabria, a Bonanza, and a 450 hp supercharged Stearman.

    They all have their starting quirks — more of a nuisance than a “perk.” I think those who want engines to be difficult to start are among the egotistical “good ole boy” pilot fraternity.

    If we want general aviation to grow, we need remove as many barriers to entry as possible. Anything that can simplify/facilitate the starting of our primitive reciprocating internal combustion engines would be beneficial to this end — until the real game changer comes along: batteries with many times the current available energy density.

    An electric airplane would be as simple as turn it on and go. Other benefits: far fewer parts to fail, simpler maintenance, no danger of carbon monoxide in the cabin, zero emissions, no power loss or mixture adjustment with increasing density altitude, smoother, quieter, no weight shift with fuel consumption, less heat so less cooling drag, possible partial electrodynamic recharging during descent, possible range enhancement or free recharge during prolonged parking with solar cells on wings, aerodynamically cleaner nose due to smaller cross-section of electric motor vs. combustion engine. An electric motor is significantly lighter than an equally powerful reciprocating engine. The challenge will be to get batteries with the same range per weight as avgas or diesel.

    John F. Kennedy’s “We choose to go to the moon…” speech along with taxpayer money funding NASA, got humans on the moon over 50 years ago. The “X-Prize” got civilian flight to the edge of space via Burt Rutan. We need a “B-Prize” for the first battery to safely offer (without risk of meltdown or fire) sufficiently rapid charging, number of lifetime charging cycles, and energy density to make it a true alternative to combustion fuels. An engineer will need to decide what specifically (numerically) to include in those parameters.

    • I share your enthusiasm for electric flight, but not your optimism. In this case, chemistry is not our friend. The periodic table lists lithium as the most chemically and electrically reactive element. However, that reactivity also makes it very temperamental and hard to manage. Unless someone can discover some unobtanium or a different way to pack electrons into a small, lightweight container, liquid fuels will be the winner for some time to come. There is no reason why a modern combustion engine cannot be developed to replace the current offerings from Continental and Lycoming. Sadly, economics and pilot inertia (resistance to change) seem to be the biggest roadblocks.