The Pilot’s Lounge #142: Safe Airplanes, A Cautionary Tale

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The stall-proof Weick W-1, which led to the Ercoupe.

Due to a mix-up on my part, I walked into the pilot’s lounge at the virtual airport an hour prior to the time I was scheduled to fly with a student. I found a magazine I hadn’t read and sunk into one of the worn, old recliners, trying to keep quiet so I wouldn’t interrupt the instructor and student on the other side of the room. Karver was there, with his instructor, Sandy. Karver is becoming known at the airport for his combination of determination and pragmatism—he went through the private rating in two months, recently finished up a tailwheel checkout and is well along toward his instrument and commercial tickets. On top of that, he has made it clear that when he learns something, he wants to know why it’s important, otherwise he wants to skip it. That has kept his Sandy on her toes as she works with him.

Karver is in the midst of a checkout in the flight school’s Cirrus SR22, a machine that qualifies as a technically advanced airplane (TAA). It has an IFR GPS with moving map, a multi-function display with weather graphics and an integrated autopilot. Karver’s goal is to fly professionally, so getting comfortable in a TAA is going to be essential. He’d been flying the school’s “six-pack” configured airplanes because they are less expensive to rent than the glass birds.

The intensity of Karver’s comments and questions drew my attention away from the article I was reading. “Look, Sandy, I’ve got the stick and rudder stuff down. You did that for me when you checked me out in the Citabria. All I need to do with the Cirrus is learn to program the autopilot. This airplane is expensive, I don’t have the time to do all the slow flight and stalls and steep turns and unusual attitudes—I can do that already. Besides, if something goes wrong when I’m hand flying, I’ll just activate the autopilot. The airplane’s automated, it can fly better than any human can.”

I thought Sandy was going to come unglued. She had been a freight dog, retiring after years as a captain on the Boeing 777. If anyone knows automated aircraft, she does. She suddenly got the “I’ve got to be patient” look on her face.

“Karver,” she started, “aircraft automation is designed to protect humans from themselves—and it does a pretty good job. But it’s not foolproof—and fools have long proved themselves to be ingeniously able to screw up foolproof designs. Remember when we started this checkout and you told me that you’d looked at accident stats for TAAs versus six-pack airplanes, found out that they the same and wondered why? My answer was that even with extensive automation, a pilot has to know the airplane and its systems cold because ignorance has consequences.

“Do you recall the Boeing 777 crash at San Francisco about six years ago where the jet hit the seawall short of the runway?”

“I’m not sure. I hadn’t started to learn to fly and don’t remember much about it.”

Sandy said, “Short version, an experienced crew misunderstood the automation on the airplane while flying what should have been a routine visual approach on a nice day—and their hand flying skills weren’t great. Of course, there were multiple, cascading causes of the accident but, in my opinion, it could have been prevented had the crew been used to hand flying the airplane—and hadn’t been so used to relying on automation.”

Sandy looked at me. “Hey, Rick, get over here.”

I complied, sitting down at the table with Karver and Sandy. She continued, “Didn’t a buddy of yours have an engine shell on the triple-7 he was flying over the middle of the Atlantic a few months ago?”

Yes, he did.”

Sandy looked at Karver, “That one had a happy ending because the crew had been well trained and knew the airplane systems cold, including what the automation would and wouldn’t do for them. They turned off the overseas route they were on, descended away from traffic to an altitude they could hold on one engine and flew 90 minutes to a safe landing in Ireland because of good training, their skills, judgement and knowledge.

Know the Systems

A Cirrus SR22 panel.

“I’m requiring you to know the systems of this Cirrus inside and out and to be able to hand fly it in any condition as well as to make sure you can make the automation sing. That’s because aviation is a microcosm of machine development for humans. Whenever we design a safer machine, that set of humans clear over on one side of the bell curve where it says 'damn fools' find a way to disable the safety features either by actively taking them off or deciding that the machine is so safe that they can do anything they want and the machine will protect them.”

“What are you talking about?” Karver interjected.

“I pulled Rick over here because he’s an aviation history geek and worked for a manufacturer—he saw some of the stupid things pilots do first hand. Plus, he writes for Aviation Consumer magazine and every month he has to read 100 accident reports on a type of airplane for their Used Aircraft Guide. If you’ve got a minute, I’d like you to get some background on how pilots have sabotaged safe aircraft design over the years so you’ll understand why I am adamant about you learning everything you can about the Cirrus before I sign off your TAA endorsement. OK?”

Sandy looked at me, “Tell Karver what you told me about shoulder harnesses when you worked at Cessna.”

Unused Shoulder Harnesses

“Cessna made shoulder harnesses standard for the front seats well before the FAA required that they be installed. At first, many pilots and passengers refused to wear them. Surprise, surprise, a lot of people died in fairly minor accidents by smacking their head into the panel—jackknifing over the seatbelt—with the shoulder harnesses neatly tucked into their holders.

“Cessna offered—as an option—a fairly sophisticated (for the 1970s) inertia-reel shoulder harness that was integrated with the seat belt. They were comfortable and were right up there in the technology world at the time.

“I saw foolishness on a level that astounded me when a new Cessna 182RG came back to the factory from a private owner for some reason or another. It had the integrated inertia-reel seatbelt and shoulder harnesses. To my utter disbelief, the owner had cut the shoulder harness off of the seat belt portion of the system. Both shoulder harnesses were retracted back into the reels, leaving only the seat belts. An excellent restraint system had been rendered useless.”

Karver looked astonished. “How could anybody be so stupid?”

Sandy laughed and said, “You got me. You want to hear more?”

He said, “You bet.”

“Ok, Rick, tell him about your research into Ercoupe and Skymaster crashes.”

Safer Airplanes

Before I could say anything, Sandy went on, “Karver, you need a little background—in the 1920s and ‘30s the scourge of aviation was a staggeringly high rate of stall/spin accidents. It was so bad that there were competitions to encourage development of a stall-proof airplane. The demand resulted in the Ercoupe—which later became the Aircoupe—a very cool two-place airplane that had the up-elevator travel limited so that it could not stall. It also had the ailerons and rudders interconnected and operated by turning the yoke. A lot of them were built and if you ever get a chance to fly one, do it, it’s a lot of fun and astonishingly easy to fly.

“The other big killer of pilots was after an engine failure on a twin—unless the pilot kept the airplane going fast enough, it was physically impossible to keep the thrust of the engine developing power from turning and rolling the airplane toward the dead engine. That minimum speed is called Vmc. The loss of control—that usually leads to crashing fatally—is called a Vmc roll.

“If the aircraft’s engines are lined up with each other—'centerline thrust'—there is no turning tendency when one quits. It eliminates Vmc—making the airplane much safer. There were some centerline thrust twins built in the 1930s and ‘40s, mostly by Dornier. In fact, the Dornier 335 was the fastest piston-engine airplane in World War II.

“In the 1960s, Cessna decided to market a centerline thrust twin, the 336 Skymaster, in hopes of starting a line of twins that were safer to operate, because Vmc crashes were still killing a lot of people. The 336 Skymaster had fixed gear and wasn’t very fast, so Cessna made the retractable gear, 337 Super Skymaster, which had better performance but still wasn’t as fast as most wing-engine twins.

Same Accident Rate

“Ok, I’ve talked too much, Rick, you’ve looked at Ercoupe and Skymaster accidents. What happened? Did those airplanes specifically designed to be safe have lower accident rates than their competitors?”

“Unfortunately, no. While Ercoupes don’t have any stall accidents to speak of and Skymasters don’t crash because of Vmc loss of control, the accident rate for them is not different than the accident rate for their peers.”

Karver looked thoughtful, “If you take away the risk for one type of accident, how come the overall accident rate isn’t lower for those airplanes?”

I looked at him. “I think it’s tied in with what Sandy was talking about—safe airplanes attract the full spectrum of pilots for all the reasons anyone buys an airplane, but I think they also attract that end of the bell curve of pilots who consciously or unconsciously rely on the safety built into the airplane to compensate for their poor judgement, unwillingness to keep their skills up or pay what it costs to keep the airplane in good shape.”

“You’ve looked at all of those accident reports. Was there anything in them that pointed to Ercoupe and Skymaster pilots, as you put it, relying on the safety of the airplane?” Karver asked.

“Have you got time for a few examples?”

“Go ahead,” Karver responded.

“OK, but before I go on, please understand that I’ve spent a fair amount of time flying Ercoupes and Skymasters and really like them, so I may be biased."

Ercoupe

The stall-proof, two-control Ercoupe.

“The last time I looked at the 100 most recent Ercoupe accidents I saw that there were 26 crashes due to engine maintenance issues. Most of those were because maintenance hadn’t been performed—including several that involved original parts that had simply worn out more than 50 years after being installed.

“There were seven fuel-contamination accidents that were also maintenance-related—the contaminants included foreign material, often rust, that should have been found and removed during routine maintenance. That’s twice the rate of failure to do fuel system maintenance than I normally see when I look at 100 accident reports.

“Two Ercoupe owners decided to perform aerobatics in their airplanes and pulled them apart inflight.

Ercoupe accident

“There were seven inflight loss of control (LOC) crashes. Even though an Ercoupe won’t stall if the pitch controls are rigged correctly, they will set up a very high rate of sink at low airspeeds. If the airplane is in a steep turn, full power is not enough to allow the airplane to maintain altitude—the bank angle has to be reduced dramatically. LOC on an airplane as incredibly easy to fly as an Ercoupe is an indication, to me, of a serious lack in pilot skill or judgement, or both.

“Eighteen Ercoupe pilots could not judge their descent toward the runway. Seven didn’t make it to the runway; they hit obstructions first. The other 11 didn’t arrest the descent and hit so hard that the airplanes suffered structural damage. That rate is about three times higher than I expect to see when looking at accidents of other aircraft types.

“Finally, one Ercoupe owner was approached by a father and son who wanted to fly his airplane. Neither had any flight experience. The owner gave them the keys. They were able to make a successful takeoff and climb to about 250 feet before the airplane was observed to descend into the ground. Neither survived.”

“Good grief,” Karver intoned solemnly. “OK, what about the Skymaster?”

Skymaster

The centerline thrust Cessna 337 Skymaster on takeoff.

“For me, the weirdness started when I read that five pilots intentionally tried to depart with one engine inoperative. Most died. In three of those events, other pilots tried to talk them out of it. One of those involved an airplane that had not had an annual inspection in 10 years. To me, that’s a pilot relying on the built-in safety feature of the airplane to overcome his foolishness.

“There were six crashes in which one engine failed after takeoff and the pilot took no action to feather the prop on the dead engine—as with any piston twin, it won’t hold altitude without feathering the prop on the dead engine. The good news is that most survived because the airplane stayed upright during the descent to the forced landing—no Vmc roll, so the safe design saved them.

“Fifteen of the 100 crashes were fuel-related. That’s twice the rate for tip-tank Cessna 300- and 400-series twins, which have a much more complex fuel system. I think the tip-tank twin Cessnas have a reputation for a complex fuel system so the pilots treat it with respect—unlike the Skymaster, which has a reputation for a simple fuel system.

Skymaster accident

“However, in the world of strange accidents, right up there near the top is the owner who stripped out the interior of his Skymaster as part of a refurb project. He departed on the flight to the shop that was going to install the new interior. En route, he ran the mains dry and then realized that in gutting the interior he had removed the fuel selector handles. He was unable to change tanks."

“Yikes,” was all I heard from Karver.

“Nine Skymaster pilots lost control of their airplanes in IMC—about double what I expect to see when I do an accident report review. Five of the 100 accidents involved pilots who had incapacitated themselves with drugs or alcohol. Nine pilots tried unsuccessfully to fly VFR in IMC—nearly double the rate I generally see in accidents in other types.”

Karver hadn’t moved. He blinked a couple of times, turned his head to Sandy and said, “OK, Sandy, you’ve got my attention.”

Effective Safety

Sandy looked at him seriously. “Karver, I think that the integrated glass cockpit is one of the reasons that the airline and bizjet safety record is as high as it is. I like TAAs, but the safety built in to them is only as effective as the training, judgment and skill of the pilot whose sweaty hand is on the yoke. We’re in the midst of what I think is the next step up in making airplanes safer—but, in the general aviation world, I think whether we’re able to take that step is going to be limited by the willingness of pilots to keep their level of judgment, skill and knowledge so high that they don’t have to use the safe design as a crutch to overcome their own shortcomings.

“So, are you willing to bury yourself in the Cirrus manual and learn the systems inside and out and spend some time hand flying the airplane?”

Karver nodded at her. “It looks like I’d be a damn fool to do anything else.”


Rick Durden is a CFII, holds an ATP with type ratings in the Douglas DC-3 and Cessna Citation and is the author of The Thinking Pilot’s Flight Manual or, How to Survive Flying Little Airplanes and Have a Ball Doing it, Vols. 1 & 2.

Comments (2)

Great article! Thanks for sharing. In Langewiesche's book on Flight 447 he talks about the pilots staring at the displays waiting for something. There had been training on how to deal with this situation but the crew never did it. I kept thinking if an instructor pulled this on a student in a Cub or 172 the answer would have been easy but when you have to communicate through technology to the airplane it changes the dynamic to where the crew can become passive observers if they lack the understanding of what the plane is trying to do.

Posted by: John Randall | January 19, 2019 12:19 PM    Report this comment

Rick, did the severity (fatality) rates for safety airplanes also not improve? Mushing accidents, in modern crashworthy seats with shoulder harnesses, should be less fatal than spin crashes. In fact, modern airplanes with parachutes are proven to protect occupants in dramatic vertical impacts. We should not concern ourselves with spoiled airframes, only the humans in them.
Likewise, the physics of Center Line Thrust should allow safe single engine take-offs... provided W&B, acceleration rate, airspeed, and climb rate are compensated. We have no idea of success RATE of single-engine flights in Skymasters, right? (Are ferry permits required? why? and searchable?)

Posted by: Jeffrey L Pierson | January 29, 2019 1:16 PM    Report this comment

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