There’s More To Starting An Airplane Engine Than Luck

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Yesterday—a nonsensical dateline since I don’t know when you’ll read this—I encountered the unimaginable. Asked to move a friend’s Nissan Altima (car not an airplane), I pressed the brake and turned the key. I didn’t first check the oil, drain a fuel sample, or yell, “Clear!” as I would in most modern airplane starts, and “modern” implies post-1949.

Nor did I prime the cylinders, energize a fuel pump, or set the mixture. Didn’t even use a checklist. Instead, I turned the key, and—this is the unimaginable bit—it did not start.  Yeah, this modern(ish) automobile acted like an airplane piston engine, the starting of which is a crapshoot that involves a fair amount of mystery theater.

“Three shots and four blades,” could pass for rejected lyrics from Leonard Bernstein’s Jets and Snarks number in West Side Story, but in classic aviation it means, “Give it three shots of prime and rotate the propeller four times (blades).” Then, “Contact!” and my Champ’s Continental four-cylinder engine will start on the first pull or balk because it’s flooded. Remedy that by making the world counterrotate to turn back time and undo what I’d just screwed up. “Switch OFF, throttle FULL.” Now pull the prop through backwards a dozen times—no more, no less. Why do we do this?

Tradition!

Forget science, aviation lore percolates through Broadway musicals, and although Tevia in Fiddler on the Roof begrudgingly acknowledged changes threatening his Minnesota airport, Anatefka Muni (6Z6), some of us are reluctant to accept what masquerades as progress. Oh sure, we luftmenschen embraced GPS and ForeFlight like maniacal gameshow contestants, after winning a Cuisinart Metamucil Dispenser, but largely we cling to familiar ways.

Examples: Raising traffic patterns from 800 feet AGL to 1000 creates a stupid waste of fuel. I’ve done the math. Replacing “Taxi into position and hold” with “Line up and wait” was pointless. Sounds like instructions at a COVID up-your-nose site. When tower tells me to line up and wait for GodotAir to clear the runway, I rebelliously taxi into position on the runway and hold my tongue after compliantly reading back the instructions.

Non-pilots think that landing an airplane is the most difficult phase of flight. It’s not. All airplanes will eventually land, or as Kate Strauss, an instructor at the FAA Academy told us ATC cadets between drags on her Virginia Slims, “We have yet to leave one up there.”  The toughest part is starting a piston engine, a process in which success hinges on tradition and less from what’s in the POH.

Whether normally aspirated or fuel injected, no two piston airplane engines start the same. Toss in variables such as sloppy maintenance, or hot versus cold starts, and the process conjures more alchemy than science. This becomes overwhelmingly apparent when starting an engine by hand, and there are only two reasons for doing so. Either the battery is dead, and you’re stranded on a rapidly calving glacier, or the airplane has no electrical system. The latter applies to my daily ops, but—and I’ll risk a merit badge here—I’ve hand-propped Cessnas with weak batteries. Not recommended, but if ya gotta, ya gotta, an excuse that withers under post-incident scrutiny.

I’ve been starting my 75-year-old airplane by hand for 39 years and still have all 10 fingers. Adding those figures together nets 124, which is the number of possible ways to mangle a forearm or, worse, flood the engine if I don’t employ the exact starting ritual, perfected through trial and frustration. Beyond the “three shots and four blades” for warm weather starts, I set the mag switch to LEFT, because the left magneto alone has the impulse coupler, which retards the spark for easier starting. Easier being a relative 1940s term. Magneto being an 1890s term.

With the left magneto set to fire, the throttle is “cracked,” a calibration defined at the Council of Trent in 1545. Cracking in my airplane is 5/16 of an inch (7.95 mm). Once all steps have been met, the person dragooned to spin the propeller does so with precise downward pressure and snap to rotate the crankshaft to trigger the mag spark that ignites the compressed fuel/air mixture, while not lingering in the propeller’s arc during that millisecond, perhaps longer, as the power-stroked cylinder inspires the others to explode in sequence. For my engine that order is 1,3,2,4, repeat. It’s a chemical/mechanical marvel. The marvel being it works at all, which occasionally it doesn’t. Usually when already apprehensive passengers await.

Flashback: It was a warm sunny day in Idaho. I was climbing aboard my Cherokee 180, when I noticed a Piper Turbo Dakota (235-HP), loaded with three passengers and a pilot with epaulets on her crisp white shirt. I was less envious of the charter captain’s insignia than of the Dakota’s turbocharger, as my normally aspirated Lycoming had been wheezing asthmatically through the high country. Captain Dakota made certain the airplane door was secured before she cranked the engine. Multiple times. Nothing happened.

Sealed inside the Piper solarium, passengers wilted like wax figures in a sauna. I was impressed with the Dakota’s battery as it cranked the starter, intensifying futility to the rhythm of Ravel’s Boléro. Trying not to display pride after my normally aspirated Lycoming fired up, I taxied past the Dakota and its captives.

Airborne, I turned on course with smug pride, knowing that following my traditional start procedure always works. Then, I remembered I’d left my wallet on the FBO’s counter. Chagrinned, I 180’d the 180.  The now running Dakota was holding short of the runway for all the passengers to witness my bounced arrival. After taxiing to the FBO, retrieving the wallet, and climbing back into the Cherokee, I watched the Dakota lift and turbo its way home, relieved of the Karma that had left it to climb aboard with me.

Somewhere in a quantum parallel universe there sits a Cherokee 180 with a heat-soaked engine and a younger me running the battery down, doomed to spend eternity trying to get it to start. Yet grateful it wasn’t a Nissan Altima.

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16 COMMENTS

  1. All of which is the real reason I read AVweb. Thanks Paul for again reminding me why. “luftmenschen”, “Piper solarium”, “intensifying futility to the rhythm of Ravel’s Bolero” are the unique province of this space which is where i come to relax hoping to read something impervious to politicization or culture war fodder. Sometimes like today, a “nonsensical dateline”, it happens. Now back to my pull T-handle and primer equipped C-90 which will start 100% of the time on the first pull winter or summer. Hot and hung starts need not apply.

  2. Over the last few years, I have been suffering a different sort of airplane starting problem. I am reasonable adept as priming the (not hot) Continental IO-360 and getting it to run on the first or second cylinder to pull through a compression stroke. The trick is getting any of the cylinders to pull through. The Rube Goldberg Continental starter adapter slips. Not always, of course. And never on command. It happens more when cold, but I live in Texas so that never happens anyway. Except sometimes it will slip without being cold.

    If that wasn’t enough, the battery isn’t brand new. So I have a sleepy battery rotating a starter that is barely connected to the engine. But if all of those things line up, I can make the engine itself run.

    I was stuck once at an airport with a really dead battery. I asked the old man who ran the airport for an external power start. He said that external power was available for $20 but if I thought I could get the engine started easily he would hand prop it for free. I think if I ran the airport I’d charge for the hand prop and give away the external power for free, but hey it was his sandbox. So I took the hand prop from the old man, and I got the fire lit in one try.

  3. Boy ! I normally respect what Paul has to say but really everyone knows the secret to the start is how you hold your tongue. When it is in that just right position just slightly rotated in the proper direction with just the right amount of tension the engine will start 😉

  4. There have been many occasions when I would have loved a starting handle on a non-starting car. At least aircraft manufacturers, at least for the type I fly, always provide one in the convenient form of a propellor 🙂

    • Starting handle wouldn’t do you any good. Due to the current “chip” shortage – someone probably stole the one out of Paul’s Nissan – and without the “chip” – nothing is going to work. Not even the 5/16″ throttle arm setting. 🙂

  5. A few years ago, I “wore out” the A65 on my Chief, making metal on the oil screen (was a main bearing slowly coming apart). Got me a used engine, recently overhauled, with two new Bendix mags on it. Engine hung, went to start it. Kicked back like crazy each pull until it started finally. Turns out it only had impulse coupling on one mag, not both. All my previous engines had dual and I always started them on both. Took me many years of propping to discover left only.

  6. With my carbureted engine I just prime it, then it starts right up. My fuel injected plane, and at the classic 20 min. since shutdown time, that’s not a given. Usually the flooded engine procedure is the most reliable. There’s other procedures that work, like moving the throttle in and out fast, or bumping the boost pump on and off. All trying to make it run with percolating fuel in the over-the-cylinder metal injector lines. But these engines are easy still. The real song and dance procedures comes when starting an R-2800 or R-1830.

    • Whereas that is certainly a PIC prerogative, depending on the airport and how packed the final might be, you might be holding short for quite a while if you miss that departure opportunity. And you might be requested to scoot over to the side and let the others waiting get past you. The controlled airport procedures now require that if you are told “taxi into position and hold”….such a better phrase, you will be advised of any traffic on final, and the traffic on final will be advised of you. Here’s the short version of the .65, paragraph 3-9-4. You can take the boy out of the tower but you can’t deprogram the tower out of the boy.

      a. The intent of LUAW is to position aircraft for an
      imminent departure. Authorize an aircraft to line up
      and wait, except as restricted in subpara g, when
      takeoff clearances cannot be issued because of traffic.
      Issue traffic information to any aircraft so authorized.
      Traffic information may be omitted when the traffic
      is another aircraft which has landed on or is taking off
      the runway and is clearly visible to the holding
      aircraft.
      Do not issue a landing clearance to an
      aircraft requesting a full−stop, touch−and−go,
      stop−and−go, option, or unrestricted low approach on
      the same runway with an aircraft that is holding in
      position or taxiing to line up and wait until the aircraft in position starts takeoff roll.
      EXAMPLE−
      “American 528, Runway Two−Three continue, traffic
      holding in position.”
      “Twin Cessna Four Four Golf, Runway One−Niner Right,
      base approved, traffic holding in position.”

  7. Great and entertaining article! My 1975 Grumman Tiger starts before a full rotation of the prop if I give it three shots of prime, CLOSE the throttle all the way, and crank as soon as possible after the prime. Since I started doing this (and changed to my current mechanic shop) the engine has failed to start only when there was something that needed fixing (dead battery).
    “Line up and wait” is ICAO terminology which is uninformative compared to the old FAA phrase, but when the controller says X and you know what X means, just do it because it means the same as the old phrase.

    • I guess I am too old and stuck in my ways. Replacing “Position and hold” with “Line up and wait” is just dumb, ICAO or not. I guess I had not been paying attention when it changed, but my first experience with it went something like this:

      Me: Tower, Cessna 123 holding short runway 17.
      Tower: Cessna 123, line up and wait 17.
      Me (confused): Tower, say again?
      Tower: Cessna 123 line up and wait on runway 17. (Pause) That’s the new term for take position and hold.
      Me: Uh, okay, taking position on 17 and holding, er, waiting.
      Tower: (with a chuckle) Cessna 123 cleared for takeoff.

      I’m not sure in what universe line up and wait is any easier to say or clearer to understand than position and hold. Whenever a tower guy tells me to line up and wait, I respond “Position and hold” for Cessna 123. I have yet to have one correct me.

  8. “Whether normally aspirated or fuel injected, no two piston airplane engines start the same. Toss in variables such as sloppy maintenance, or hot versus cold starts, and the process conjures more alchemy than science.”

    Modern cars, particularly starting (no pun intended) with Japanese cars, starting (no pun intended) in the middle 80’s began the refining process of removing any personality out of automobiles. All auto manufacturers now largely follow this principal. Drive just about any brand today, most look the same, drive the same, start the same, have the same interior colors, smell the same ( at least initially),and get you reliably to your destination. The majority of drivers today want no more of a sequence regarding starting their cars and trucks other than what is required to “start” one’s cell phone. No personality starts, no personality driving characteristics, and drive up maintenance to be done by someone else while the owner sips a Big Gulp and scrolls the latest buzzword from Twitter, FB, and Pinterest. Unplug just long enough to hand over the debit card, and hear the reassuring sound of the hood being slammed shut to drive to the next drive up service venue. All being commanded by various screens and prompts from the dashboard. No thinking required. Just reaction to the information directly injected by the vehicle to the driver.

    The challenge for flight schools today is teaching the art and science of flying, which includes the “the process” that “conjures more alchemy than science.” of starting an aircraft engine…new or old…since most new aircraft engines of today are essentially old. Add to this mix of mysteries the fact there are new and newer/used/older Rotax aircraft powerplants in the aircraft fleet, but are primarily purchased by older pilots who are more familiar with the old than the new. Interesting paradox worth exploring Paul when watching an older, steeped in experience of decades of Armstrong starters, pressure carb Bonanzas, and heat soaked mechanically fuel injected IO anythings completely mystified by simply turning a key on their Rotax powered RV-12.

    Since many of us know you once owned an early, pressure carb equipped Bonanza, I would love to have you comment on the flurry of arms, hands, careful digit placement in the right sequence, in the exact perfect location both under the thick, therefor blinding control yoke, and simultaneous vigorous left arm/hand use of the wobble pump to bump the starter a microsecond to engage all the starting gear mechanisms, then fully engage the starter button while wobbling on the wobble pump, and after having the exact number of turns preset on the vernier throttle. Hot starts add yet another dimension to this starting alchemy…. that being exactly when do I wobble? Wobble of not to wobble. That is the additional question when heat soaked. Alchemy indeed.

    Modern flight schools need to be proficient in teaching students the art of walking, chewing bubblegum, and rubbing one’s belly while in a heads up, face forward position…at the same time. Once that is mastered, then the possibility becomes more real that said student will embrace flying which puts personality back into the machine at all levels of the total aviation experience. Part of that total emersion aviation experience is the alchemy of an engine start.

    Cirrus has done a pretty good job of refining out the personality of the airplane making it relatively, somewhat closer to the now generic car. But even Cirrus is stuck with the engine start mystery. Cirrus customer service has been forced to train the new owner in combining some aviation personality ( the engine start…or lack of) with carlike lack of airframe personality being guided by more and more automation.

    GA aviation while be in serious trouble when and if the FAA allows modern engine management systems prevalent in our personalityless, generic cars and trucks to aid companies like Cirrus to further refine the airplane into an aerial version of a modern car or truck. Soon after all new airplanes will be silver, white or black, with grey or tan interiors, with engines that start at a simple touch of a button, while the pilot scrolls through one’s cell phone or tablet, as the glass panel tells the operator ( there will be no more pilots, just operators) when to move, who to call or talk to, in the right sequence, with the correct aviation verbage, direct the ground motions to the proper runway, apply the correct power settings, and fly the airplane. At some point the seamless automation will be able to take out the bumps of flight, with algorithms that will anticipate the air movement removing all vestiges of personality from flying.

    For those who embrace all of the personality that flying provides yet today, those same people should be eternally grateful for the glacial movement of the FAA who has and will ensure that alchemy and science will remain in GA aviation. We do have technology today that when included into GA aviation, will remove as much of the present personality that exists in what makes up learning to fly. And when that happens, what will the two Paul B’s fly and write about?

    Thank you Paul Berge for a brillant, accurate, metaphorical, and thoroughly funny article about the science and alchemy that is still in the heart and part of GA aviation!

    • You make an excellent case for the nostalgic. But couldn’t we keep some of the nostalgia and still get better engines? Maybe save a few lives in the process?

      Surely, there must be a middle road? Maybe we could have a camera on the pilot so the plane can ensure he performs the right ritual before allowing the otherwise dependable engine to start, but only when he or she is alone?

  9. Good writing includes “A good story–well told.” Berge meets both tests!

    Berge’s writing reads like a Robin Williams riff–SO MANY references that the listener or reader struggles to keep up! Examples:

    “Three shots and four blades,” could pass for rejected lyrics from Leonard Bernstein’s Jets and Snarks number in West Side Story,”—“Forget science, aviation lore percolates through Broadway musicals, and although Tevia in Fiddler on the Roof begrudgingly acknowledged changes threatening his Minnesota airport, Anatefka Muni”–” luftmenschen “–” “Line up and wait” was pointless. Sounds like instructions at a COVID up-your-nose site.”–” intensifying futility to the rhythm of Ravel’s Boléro”–“waiting for Godot-air”!

    Again–it’s like Robin Williams “I can talk faster than you can think!” WELL DONE, Mr. Berge!