American airlines airplane
7 min read

Several years ago after the TBM, PC-12 and Piper Meridian were well-established as sales successes, I asked executives from each manufacturer if the worry about having only a single engine ever came up in discussion with prospects. Each answered no. And each had the same explanation. “People have already decided they are OK with only a single engine before they ever talk to us,” they told me.

The people willing to own and fly a single-engine airplane have made a deal with the devil.

That deal does sort of involve eternal souls, as the motif implies, but more specifically puts everyone onboard the single-engine airplane at risk. Ask anybody you meet what happens when the only engine on an airplane fails and they all get the answer right. The airplane comes down.

TBM 900

Pilots of single engine airplanes make a deal with the devil – and that’s OK.

People who fly singles are willing to take the risk of engine failure in exchange for lower costs, higher payloads, greater fuel efficiency and the other benefits that come from feeding only one engine. Their deal with the dark side is that the risk of total power loss is small enough that it almost certainly won’t happen to them.

Such deals with the dark side are actually pretty common in everyday life. A glaring example is riding a motorcycle. The risk of traveling on a motorcycle versus a conventional vehicle are as obvious as the risk of flying a single. And many—even most—riders object to even the most basic risk management such as helmet requirements. Millions of people decide the risk of riding a motorcycle is worth it to them. And you can think of many, many other examples of trading risk for something more valued.

For decades anyone who flew as pilot or passenger made his or her own deal with the devil. The risks in flying were just inherent and unavoidable. The flying risks could be reduced, but still loomed large. Just run an inventory in your mind of all the celebrities, rock bands, and movie stars killed in airplane crashes in past years. And we only remember them because of their fame. Fatal crashes in all types of flying until sometime in the 1980s, or maybe 90s, could rightly be called “commonplace.”

But that has all changed at the top of the aviation pyramid. When you fly on a major airline in an advanced country, or in a corporate airplane operated by a well-organized flight department, your risk of being killed is very close to zero. There has been no fatal crash of a U.S. jet airliner since 2001. The only major airline passenger killed during that period was aboard a Southwest Boeing 737 when flying shrapnel from an uncontained engine failure broke a cabin window and caused the injuries. The devil has lost his bargaining power at the top end of aviation.

Flying major airline or corporate jets has become so close to risk-free because technology advanced to the point where we no longer must trade risk for the speed of air travel. Airplanes and equipment became more reliable in all respects. More importantly technological advances make is possible to add layers of essential structure and equipment so that no single failure, or even foreseeable multiple failures, can prevent the airplane from reaching a runway.

Turbine engines are now so reliable that a failure is extremely rare. And in air commerce or business jet flying, every flight must be planned so that from takeoff to touchdown the loss of the most critical engine cannot prevent the takeoff and return to a runway from ending safely.

The primary structure of airline and corporate airplanes must now demonstrate that it is “damage tolerant.” That means that the failure of any single element of the structure cannot prevent the flight from concluding safely. Spars, for example, have multiple elements any which of can carry limit load.

And in airline and corporate jet flying all crews must be trained and checked to standards unheard of decades ago. Absolutely realistic simulators are the basis for training so pilots experience and handle critical situations at least once a year even though they almost certainly will never experience such an emergency in flight.

For the past several decades very serious people from all disciplines of aviation have sat through countless meetings running endless “what if” scenarios. The goal is that no “what if” question can lead to loss of the airline or corporate aircraft more than once in a billion flights. Since no piece of machinery, electronics or structure can possibly meet that standard the certification and operational rules have been created to require multiple backups for everything necessary to continue flying after a failure.

I can hear some of you yelling at your screen, “What about Sully and Jeff Skiles? They couldn’t continue flying after a failure.”

American airlines airplane

The airlines have essentially solved the safety problem. But at what cost?

You’re right. But, has the loss of both engines in a transport category jet happened more frequently than once in a billion flights? Since I can’t think of another episode, absent crew mismanagement of a failure, where all power was lost in a transport jet, I think the one in a billion goal was satisfied. Which makes the Miracle on the Hudson even more of a once-in-everyone’s-lifetime event.

My point is that as an industry, an activity, we in aviation know how to take the devil out of flying. What is required is significantly higher cost and loss of convenience.

The cost of near total safety is obvious in the number of engines, systems and structural redundancy required. But less apparent are the necessary operational restrictions. For example, want to fly your “safe” airplane by yourself? Sorry. A single pilot comes up short on essential redundancy. Want to use that nearby but shorter runway airport? Nope. You must have enough pavement to safely abort or continue a takeoff after an engine failure at the worst possible moment. And you must certainly have enough runway with large margins for stopping on landing. Don’t want to feed and maintain another engine “just in case?” Sorry. That also misses the maximum safety goal.

So for personal aviation to continue and deliver the convenience, and even recreation, many of us want, we must still make that deal with the devil. And I believe most pilots are aware of that risk tradeoff, and most make conscious choices of what risk to take and how to minimize all risks to the greatest extent possible.

I know this because at Flying magazine our reader surveys showed year after year that stories about safety, accident analysis, handling weather and all other forms of risk management always ranked at the top.

Cycle World magazine was also part of our company and the editors there had a very different experience. They ONCE ran a story on improving motorcycle riding safety and readers and the industry went nuts. Riders absolutely didn’t want to hear about safety, or lack of it, or how to improve it. Each rider, apparently, had their own deal with the devil and it was their right to take on whatever risks they choose. Quite the opposite of the pilot community.

Airline and corporate flying has reached a level of safety none of us could have imagined even 30 years ago. As an industry, we know how to essentially eliminate fatal accidents. As pilots flying for our own reasons we can learn how the big boys did that, and adapt as many of the lessons as we can afford, or decide are worth the required tradeoffs. We still must make our own deal with the dark side to fly our own airplanes for our own reasons by ourselves, but I hope we are making the best and most informed deal we can.

Mac McClellan
42 replies
  1. David Yonker
    David Yonker says:

    If you read many accident reports, you can see where many single engine Pilots did make a poor deal with the Devil, willing to take on a lot of risk to make a {“dead” line} even the word is there for all to see. If you push it and get away with it, flying in bad weather, you can begin to believe you are just that good. We all make our own rules or deal with the Devil. Just give some thought to who else you are putting at risk with your deal. To read about a wife and kids that put their faith and trust in their Dad or Husband and lost their lives is very heart breaking. A simple hard fast rule is ALWAYS fly away from bad weather NEVER into it, I don’t care how many engines your Plane has or hours you have, Mother Nature likes to show off now and then.
    There is a risk in flying even on a total VFR day, IFR adds many risks take the time to know where better weather is….give your self the best chance to tell your flying story tomorrow, not NTSB.

  2. Steve R
    Steve R says:

    The only other dual flameout on a transport category aircraft I can think of was many decades ago on a Southern Airways DC9. Heavy rain and hail in a thunderstorm was, as I recall, the cause. Surely there were nearly a billion flights between that and Sully’s.

  3. Enderson Rafael
    Enderson Rafael says:

    There is actually quite a number of dual loss of thrust, including the A321 that landed 2km after taking off yesterday morning in Moscow due to… bird strike. But fuel leaks (when not well managed), wrong uplifts, extended holdings, and of course, the great concerns on that matter: ice crystals and volcanic ashes, they all brought down models like Fokker 100, Boeing 777, Airbus A330, Airbus A320, Airbus A321, Boeing 737, Boeing 767, DC9… just name it, we have like I said quite a number out there, including Boeing 707 and 747, four engines aircraft – and most of them with pretty decent outcomes on surviving rates. So, risk management goes way beyond flying on one engine only. How well is that engine kept? Is it giving any signs of having trouble whatsoever? It is totally not comparable to motorcycles. The level is much, much higher. The quality of project, maintenance and operation, this is what counts much more than the number of engines.

  4. David Megginson
    David Megginson says:

    Mac, your analysis is incomplete (not necessarily wrong, just not finished). Unless you’re talking about inline twins, there are two risk factors to balance:

    1. Singles have the risk of losing their only engine.

    2. Non-inline twins have the risk of loss of control due to asymmetrical thrust on takeoff or go-around.

    Which is the bigger risk? Which is more likely to result in fatalities? Is it different for piston and turbine operations? Once you’ve looked at that, I’ll be interested in your conclusions. As it stands, you’ve oversimplified the problem.

    • Mac McClellan
      Mac McClellan says:

      David, the risk in flying piston singles or twins is very close, and not worth arguing about. Risk doesn’t drop dramatically until you compare transport vs light airplane categories. It’s at the transport level that we give up so much flexibility to trade risk for our own goals in exchange for an enormous risk reduction.
      Mac Mc

  5. Kim Hunter
    Kim Hunter says:

    I agree with David but the LOC data might be difficult to find and correlate. Also, with two engines the probability of an engine failure in any phase of flight is doubled. Your main point stands though. Training, proficiency and currency are what seems to be driving down risk in the part 121 world.

  6. David Pendlebury
    David Pendlebury says:

    The implication that singles are more dangerous than twins (among the owner-flown fleet) was debunked by Richard Collins years ago. I really don’t understand why flying a single over a twin is making a deal with the devil. The ascendancy of the single engine airplanes and the commercial failure of light twins (again among the owner-flown fleet) is not just driven by cost but by the clear cost/hazard advantage of singles.

  7. Duane Mader
    Duane Mader says:

    Great shot of reality Mac.
    I’ve thought about the correlation between flying and motorcycles a lot recently as my brother in law’s brother was just killed on a motorcycle. There’s that moment when the driver on the cross street stops, looks right at you, doesn’t actually SEE you and pulls right out in front of you when you have no chance to avoid them. Happened to me on a racing bicycle at about 25 mph too.
    Same with single engine planes. There’s those moments during a flight when the loss of an engine will not allow for a safe landing.
    As a corporate turbine pilot my new worst nightmare is DEF in the fuel. That crap shouldn’t be allowed inside the ramp in an FBO setting.

      • Robin Oldfield
        Robin Oldfield says:

        Diesel Exhaust Fluid – required to meet current emission and particulate matter limits imposed on compression ignition engines. It is not designed to be premixed with diesel fuel but is injected during the combustion process

  8. Robert Thomas
    Robert Thomas says:

    Pilots operate in an environment controlled largely by the behavior of pilots. Generally a pretty responsible and professional bunch. Motorcyclists do not. The hazards are manifold. Beyond a good helmet, leathers and ABS brakes, there isn’t much to do to mitigate that risk, other than riding in remote areas. Flying means that my decisions and skills, or lack thereof, determines my fate. Not someone “piloting” a 3-ton SUV, whilst texting with their dog in their lap, and sipping on a beverage. After being almost killed twice, and owning 13 bikes, I gave it up. I still fly though, and will as long as I can.

  9. Jack
    Jack says:

    The questions of when, where and how we fly singles are far more significant than the selection of a multi-engine type when it comes to safety.

  10. Lee C
    Lee C says:

    How about ‘We Trust in God and Our Abilities’?? Quite frankly, I never make a deal with the Devil as the root word is -EVIL-

  11. Bruce
    Bruce says:

    I am not sure of the point the author is trying to make. Yes it is risky to fly a single engine. Yes it is risky to drive a motorcycle. Is a glider even more risky than both? By what percentage? The difference between riding a motorcycle and flying any aircraft is a training regimen that emphasizes safety and training. Last time i checked in my province in canada there is no special training to get a motorcycle license. A figure eight in a parking lot is all it takes. Single engine, A deal with the devil?? Hardly. But nice click bait headline.

    • Mac McClellan
      Mac McClellan says:

      Hi Bruce,
      My point is transport jet flying safety has advanced to levels none of us could have imagined even 30 years ago. Personal flying safety has not. As an industry we now know how to fly with near perfect safety. The trade is a deal with the devil where we forego known safety equipment, procedures, restrictions and training to enjoy lower costs and almost unlimited flexibility in our personal flying. I hope each of understands what we trade in safety, and our passengers do, too.
      Mac Mc

  12. Joel Godston
    Joel Godston says:

    Another GREAT Aviation article Mac… I received pilot training in the US Air Force flying Piper Cub, T-28, and T-33, ALL single engine aircraft, to obtain my wings…and then T-33 and B-47 aircraft in General Yeager’s SAC…then T-33, F-84, and F86H in the Mass, ANG… finally owned and flew a Cessna 182…. a total of 50+ years of flying. While in Air Force pilot training I lost power (fuel starvation)… and ‘dead sticked’ the T-33 to a perfect landing back at the ‘home’ Air Base. I received 150 merits for doing a excellent emergency landing… However, I received 1500+ demerits for not turning the fuel on! … I had incorrectly analyzed the problem as an engine turbine failure (the same indication as a loss of fuel)…. Learned a GREAT lesson… be sure to check everything you can before ‘jumping off the cliff’… If I had just turned on a switch from one of the wing fuel tanks, the engine would have continued to operate.

  13. Richard Herbst
    Richard Herbst says:

    Back in the real world where most of us fly behind pistons designed 75 years ago, the only real hedges to chance calamity are training and staying on the ground. If any part of a thing is designed to spin, some part of it will fail, fact not theory. Most civilian pilots will choose an advanced single over a predictably safer twin. Training is not an alternative to having two engines. It’s a mandate for being in any situation where there is risk. I can’t think of any situations that don’t have some risk or call for some thought-out response.

  14. Ethan Levi
    Ethan Levi says:

    I just returned from a family vacation in the high Sierras flying a single-engine, turbo Mooney 231 with my entire family (total of four) on board. For a Mooney, this is a tough ask. Density altitude, weather, aircraft weight, alternates, and fuel stops were constant concerns. Leg length was a particular hassle because I could only carry a portion of total fuel due to weight concerns. This trip had me pondering the purchase of a twin, or at least a bigger single. Besides cost, the strength of a single is it is half as likely for an engine to fail; you only need to attend to the maintenance and care of a single engine; and, when an engine fails you must do only one thing, land safely.

  15. Robert Patlovany
    Robert Patlovany says:

    Leighton Collins, Richard’s dad, wrote four articles about a much worse deal with the Devil. His fourth, February 1968, showed a far superior 1928 Australian alternative to the unsafe hemispherical cruising altitude rules, FARs 91.159/179. See Air Facts, Feb 1968, Automatic Altitude & Heading Separation. Write [email protected] for a copy. My own analysis in 1997 Risk Analysis: An International Journal, proved obedience to these FARs is six time more dangerous than random altitude flight. The deaths from 1963 caused by the FAA mistake first written about by Leighton Collins, and analytically proven by me, and corroborated by NASA Ames Russ Paielli, far exceed the deaths at Tenerife North Airport, incorrectly known as the deadliest accident in aviation history, in 1977 when two Boeing 747s collided on a runway, killing 583 people. I estimate over 800 have died internationally since the FAA made their FAR 91.159/179 technical error Sept 30, 1963, that Leighton was the first to condemn. If you are an EAA member, watch ( what over 600 pilots learned about these deadly FARs before 89% of over 600 voters decided these deadly FARs need to be abandoned for one three far better alternatives. Leighton’s favorite (and mine) won 66% of the votes, compared to the 11% that have sold their souls to the FAA devil regulations.

  16. Bill Miles
    Bill Miles says:

    But, has the loss of both engines in a transport category jet happened more frequently than once in a billion flights?

    Air Transat Fuel Leak
    DC-9 Thunderstorm
    At least one volcanic ash incident (restart successful)
    Several four engine jet fuel exhaustion crashes (Portland/Long Island, etc), probably others I am not thinking of right now
    BA 777 fuel icing
    Challenger contaminated fuel
    Citation deadstick contaminated fuel probes
    Recent Russian birdstrike
    MD-81 Ice Shed Ingestion

    Whether some or all of these “count” or not depends on the rules for counting.

    Mac MCCLELLAN says:

    Hi Bill,
    You’re right about total power losses in transport category airplanes. But nearly all were the result of failures to follow procedures by either the air crew or ground crew.
    However, the double flame out of the Southern Air DC-9 after flying into a hail storm in 1977 was revealing. Before that engine designers and regulators believed it to be impossible for rain to drown a turbine engine. The compressor section heated the air by hundreds of degrees before it reached the combustion section so how could water put out the flame?
    It turns out that hail is different than rain drops. Hail stones travel farther up the engine before melting into water and then steam than had been previously understood. Testing was able to duplicate the effects of hail after the accident and those tests led to new design and certification requirements for engines to try to prevent a future failure from hail ingestion.
    The Southern Air crash also taught pilots to stay even farther away from thunderstorms because hail can cause far worse damage than cracking the windshield and smashing the radome.
    Mac Mc

  18. John
    John says:

    Most, if not all of the comments are from pilots with far more experience than I. That said, I find the devil’s trap for many pilots is the insistence that they can no longer fly the aircraft they have the most experience with, basic flight instruction models like the Cessna 150, 172, and Piper 140,’ etc. The problem is the old medical bit. The more the FAA requires, the more costly, and the more likely a pilot will try and do an end run by going to light, light, sport, or something worse, just to keep in the air. Maybe there is something about being too safe, because it it so dangerous.

  19. andrew mittelman
    andrew mittelman says:

    It sounds like Mac is assuming that most pilots have a choice when it come to flying single vs multiengine planes. Most of us don’t. My choice as a SEL pilot is simple; I either fly single engine planes or I don’t fly. Also, the Southwest flight given as the only instance of a fatal incident involving a US jetliner since 2001 is incorrect. In 2006 a Comair RJ went off the end of the runway at Lexington’s Blue Grass Airport killing 49 individuals. In any event, a thought provoking article. Thank you Mac.

  20. Larryo
    Larryo says:

    Mac, You have always written some thought provoking articles over the year, but deal with the devil? Hardly.

    The reason twins are safer than singles? Actually they are not, if we’re talking pistons, but can be and the answer to that is with the pilot. Most of aircraft accidents are pilot error, not because we lost an engine. And if you’re so unfortunate to crash your Baron after an engine failure, your chances of death are 4x that of a single engine crash.

    Now, if you train regularly, as a crew with your trained copilot, you can significantly increase your safety record. Not quite as good as the airlines. So if you want to be as safe as the airline, get yourself a twin engine jet and go to airline training school. And fly your jet with the same limitations as they do.

    There’s a price for the best airplane safety, and most of us can’t afford a twin jet. So, we accept the risks (and benefits) of our GA planes. But we get our training, and stay proficient. And that’s the key to not ending up with the devil.

  21. Gary Kerr
    Gary Kerr says:

    I think we need to define “safety.” As an air traffic controller, I witnessed 3 Cessna 150s lose power on takeoff (carburetor ice) and land in fields (2) and on a river sandbar (1). In all cases the pilots walked away and the planes flew back to the airport. In another incident, two large men attempted the full-flap takeoff at night maneuver. A large tree caught them, and other than some scrapes and bruises from climbing down from the tree, the men were fine. That Cessna didn’t fly again, though. One day I saw a spectacular landing that ended with a Cessna 150 sliding down the runway upside down and tail first. The pilot, a little confused with his upside down and pointed the wrong way configuration, bumped his head when he unfastened his seat belt, but after he figured out which way really was up, he made it out of the plane and walked away under his own power. Just this morning, I watched footage of a Bonanza ditching near San Francisco. Everyone got out. So while, yes, incidents involving single-engine piston airplanes are more common than they are for multi-engine jets, the single-engine pistons, in no small part due to a relatively low maximum allowed stall speed, aren’t as dangerous as one might think.

    And let’s not throw too much praise on the big iron planes the airlines fly. Yes, the airlines have a fantastic safety record, but ask Al Haines about redundant hydraulic systems in a DC-10. And remember that early demonstration of an Airbus at the Paris Airshow where the plane refused to respond to the pilot and crashed? For me, The Miracle on the Hudson, was miraculous because Sully was able to fly the plane after a double engine failure. I didn’t expect that to be possible in an Airbus. Airbus seems to be very good at creating “Smart” airplanes, but those smarts can be awfully dumb when confronted with problems the software engineers didn’t think of. Air France flight 447, that ended up in the Atlantic, probably wouldn’t have crashed if it had had less “smarts” . . . and the pilot and co-pilot flight controls were mechanically linked. Boeing went the Airbus route with MCAS and look how that “smart” system worked.

    Big Iron and little aluminum ALL have single points of failures. A wing with redundant spars means nothing if the jack screw for the stabilizer trim fails. A B-52 with contaminated fuel will suffer complete engine failure just as sure as a Piper Cub will. If a mechanic incorrectly installs gaskets or drain plugs on all three engines of an L-1011 (or was it a DC-10?), you can kiss your notions of redundancy goodbye.

    One thing, though, that makes a huge difference is the pilot or pilots flying the airplane. As an Air Traffic Controller working in Tulsa in the late 1970s and early 1980s, I made numerous FAM flights (sitting in the jump seat) every year. You might think that most of my flights would have been on American, because that’s where their maintenance base is, but, no, most of my flights were on Delta. I loved Delta! The jump seats on their DC-9s weren’t very comfortable, but the pilots were my kind of people. As both a general aviation pilot, and as an air traffic controller, I learned a ton of practical aviating from those Delta pilots. But then one year I took a flight on American. OH MY! The precision that the American crews displayed was absolutely freakish. Cockpit Resource Management was something that I don’t think existed back then, but the American crews really worked as a cohesive unit. And the crazy exactness of the way they flew! Altitudes were held EXACTLY. Airspeeds were held EXACTLY. Descending to 10,000, every time the altimeter would settle on that altitude, I’d look at the airspeed indicator and it would be exactly on 250. The guy in the right seat, when we were returning to Tulsa, wanted to do a practice CAT II approach. The Autopilot looked to me like it was doing a good job, but the co-pilot didn’t like it, so he took over and manually flew the plane, and I could have sworn that we were riding on rails.

    I had a few disturbing flights on some other airlines, but discounting the autocrat, the grump, and the “No speak-ed de English” guy on a VERY scary flight (all because this guy SHOULD NOT have been in the left seat), the airline crews I rode with were truly something magnificent to watch. (North Central guys in the Convair 580s flying in and out of O’Hare : Wow! My hat’s off to you.)

  22. Pat
    Pat says:

    Been reading articles from Mac since 1989 (Flying Magazine) when I got my PPL and then later CPL ME IR.

    Always a good read!

  23. Harry Mathis
    Harry Mathis says:

    As a private single-engine piIot, I was always conscious that I was taking a risk, especially after I got married when the woman (a non-pilot) I loved was literally putting her life in my hands flying with me. To help the odds, I got my instrument rating, installed back up alternators, vacuum pumps, dual gyro horizons, logged more than 800 practice approaches, and never flew at night. Never refused a recommendation from my mechanic, and never had an accident in my three successive airplanes. I always acted to avoid bad weather. The risks are there to be sure, but I never knowingly pushed my luck.

  24. Bob Simmons
    Bob Simmons says:

    The assumption by many pilots is that twins are safer than singles because if one engines fails, the aircraft can still fly and make a safe landing. I do not agree with that assumption for 2 main reasons:

    1) With 2 engines there is twice the chance of an engine failure than with one engine and

    2) if a twin suffers an engine failure there is still a significant level of danger if the situation is not handled properly. The recent fatal crash of a King Air that lost an engine on takeoff from Addison TX is a sad example of that.

    In any case, I have much respect for Mac and his excellent writing and piloting skills.

    Thank you

  25. JP
    JP says:

    Yeah, pilots who are basically afraid of flying to begin with or those who are just chronically paranoid SHOULD avoid single engine planes like the plague. I’ve known plenty of “pilots” like that and that’s the answer for them for sure.

    For the rest of us, it doesn’t make the slightest bit of difference. I’ve got over 20,000 hrs. in piston singles with nary a fear, concern or problem. No interest whatsoever in multis or jets. I got the multi-rating but never had enough interest to use it. After looking into what flying for an airline was actually like, I ditched that idea, too!

    Probably best if those other guys just never even leave the house! Just stay in bed where it’s “nice and safe”. And don’t EVER consider a career in a place like Alaska!! They wouldn’t last two days up there before they went running home to mommy!

  26. Gilbert Griffith
    Gilbert Griffith says:

    I think the statistics are skewed because I don’t see anything about failures caused by fuel starvation, birdstrikes, and other things that will stop a multi engined plane. Having had two safe forced landings and a lot of glider landings, I would rather deadstick a single.

    • JP
      JP says:

      Ya got that right Gilbert. I’ve dead-sticked our Super Cub right into the tie-downs a hundred times practicing for the real thing, which never happened. After a couple of times for the “new” to wear off, it’s a piece of cake to put a dead-stick anywhere you want it – just like the gliders you flew and the ones I towed.

      Never failed to get the customer’s attention when I flew over the field with a dead engine and stopped in the tie-down spot, either.

      Good times.


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