You would never guess…
Back in the heyday of piston airplanes being used for personal and business travel, one question was most often asked of owners of high-performance singles: When are you going to step up to a twin? It was automatically assumed that everyone wanted to and all would when they could afford it.
In the history of private aviation, though, new piston twins were not a big factor. They found a robust market for a relatively short, maybe 25-year, period and now they are barely a blip. About 100, of five different types, were sold in 2016. Forty years earlier, 2,155 of 25 types were sold. As a result, the average age of the piston twins is now over 45 years of age. To be fair, high performance singles, especially retractables, have also withered on the vine but that is another story.
A lot of things worked against the twin, with cost of acquisition and operation probably the biggest. But a strong underlying factor was always the inability of pilots to fly them with an acceptable level of risk and, a bit later, the unwillingness of insurance underwriters to cover them. In other words, pilots bought them because they were safe but that turned out not to be true because of the nature of the pilots who flew them.
To me, that basic pilot misunderstanding of the airplanes was a big factor in the unfortunate accident and insurance situation that developed over the years. This was our fault. We, industry, the press (like me) and the Feds (CAA and then FAA) didn’t have a good understanding of the airplanes to pass along to the users. Worse, there was a dangerous level of misunderstanding that was passed on as gospel, at least for a while.
Before World War Two, only two twins were developed that could be called personal twins. Because war was on the horizon, both emphasized the use of non-strategic material, like wood.
I saw a Langley Twin in the hangar at Linden, N. J. many years ago and it looked like a piece of fine furniture that resembled a miniaturized Beech 18. It was powered by two 90-horsepower engines so it must have been a weak performer. Only two were built. It was thus never a factor.
The Cessna T-50 was a much more practical airplane, with two Jacobs radial engines, good flying qualities and a comfortable cabin. Some of these were sold in the civilian market before the war but the really big customer, after the war started, was military. A total of 5,422 were built with most bearing the Army Air Forces UC-78 or AT-17 designation. (One was for utility, one for advanced trainer.)
Because it had been certified as a civilian airplane before the war, it was a relatively simple matter to convert war surplus UC-78s and AT-17s back to T-50 civilian status. And that is where a lot of us got our introduction to piston twin flying in the late 1940s and early 1950s, as on 7/29/52 when I got my first hour of dual in a T-50, N4692N by name.
My log shows engine-out instruction in the twin and, as best I remember it, a lot of wallowing around the sky was involved. The T-50 did not have feathering propellers and my log always showed the horsepower at 225 a side though most specs published today put the number at 245. An early (1956) Cessna 310 had 240 horsepower engines and feathering props and weighed in at 4,600 pounds max as compared with 5,700 for the T-50. The T-50 thus had one mode on one engine: forward and down.
The airplane had good stall characteristics and I don’t recall it doing anything untoward in the hands of this novice. With 232 total time and six hours in the T-50, I was sent off solo in the airplane. I got my multiengine rating on 9/10/52. I flew some charter trips in the airplane (all before I was 20 years old) but, alas, when it came up for an annual inspection in February, 1953, it was decided that would be a waste of a lot of money. Much of the fabric covering on the airplane simply wouldn’t pass the required test.
I got my flight instructor’s rating on 8/24/53 and, guess what, that automatically made me a multiengine flight instructor. Later, when flight instructors got certificates that had to be renewed ever two years, everything was grandfathered and my certificate showed airplane single and multiengine and instrument airplane.
Remember that six hours of dual I got in the T-50? Did anyone really think that would make me a serviceable instructor in the new breed of personal twins that was coming to market?
Because most other multiengine instructors had a similar history, this was a problem, probably about half of the problem. The other half was with the CAA, later the FAA.
Most of CAA/FAA people in Flight Standards were ex-military with a strong emphasis on transport pilots and those involved in military flight training. There were some bomber pilots and a few fighter pilots but it was the guys from the Air Transport Command and the Army Air Forces Training Command who called the shots. I knew a lot of them and they were tough guys who knew exactly nothing about civilian flying. They were well-intentioned but sadly misguided in a number of areas.
Trouble was not long in coming. One particular required maneuver for a multiengine rating was, in essence, purely dangerous. It required that Vmc (engine out minimum control speed) demonstrations be done as low as possible but not below 500 feet. On many twins, Vmc was not much above the stall so this meant the pilot had to fly perilously low and slow and then have asymmetric thrust suddenly introduced. The reason the FAA gave for the low altitude was to maximize the power available from normally aspirated engines.
I’ve told of this before but it is so much a part of the subject, I’ll repeat it. On July, 22, 1958 Ann and I were moving from Little Rock to New York where I would be working for Air Facts. We’d be traveling in our Piper Pacer.
One of the friends who came to see us off was Ralph Williams. He was an LRPD officer in his day job and he moonlighted as an instructor and charter pilot at Central Flying Service. After we left, and a little later that morning, Ralph went along as an observer on an FAA multiengine flight test in a Beech Travel Air, N819B. The applicant was another friend, Jim McClellan, son of the senator. The check ride was conducted by an FAA inspector and a fourth person was also along as an observer.
Witnesses described a flat spin, though I don’t think they knew what that was, entered at low altitude. The airplane hit flat and all four occupants were killed instantly.
I had flown 819B several times though no one checked me out in it. I had been flying a D50B Twin Bonanza for a local construction company, and had gotten my ATR (now ATP) in that airplane so I guess it was just assumed that I could handle the smaller Travel Air. I didn’t venture near any edge of the envelope so had no knowledge of the airplane’s low-speed handling qualities.
At the time, nobody realized that this was the beginning of what was to become a virtual slaughter caused by the way the FAA wanted Vmc demonstrated in multiengine flight training. That 7/22/58 accident was recreated dozens and dozens of times in the following years, mostly in Beech Travel Airs and Barons and in Piper Twin Comanches. After this had gone on for a while, it seemed as if the FAA was issuing multiengine ratings to the survivors of the training.
The Twin Comanche came out in 1964 and by 1968 it was widely thought of as a dangerous airplane. In normal use, it wasn’t. In the FAA-approved training it was. A third of the fatal accidents in the Twin Comanche occurred on training flights. How many of the hours were flown on training flights? At the time it was estimated that the 33-percent of the accidents happened in about five-percent of the flying time. The only other place I know if with such a serious disconnect is IFR/IMC night flying where there are a lot of accidents during a relatively little bit of flying.
The Twin Comanche was carefully examined by the government and by Piper. The main smoking gun was that in a power stall the left wing stalled well before the right wing. That would make the airplane roll to the left. I can attest to the fact that it did with great enthusiasm and more than one of us quit doing stalls in the airplane because you could quickly have to learn recovery from inverted flight when out stalling.
Piper tested the airplane in spins and found that it was recoverable using standard technique. However, most of the training accidents occurred at an altitude too low for a successful recovery. Also, with the left wing stalling first the airplane would roll to the left but most training spins were to the right. The simple reason for that was that the instructor/examiner/inspector was sitting on the right and usually failed the right engine.
Piper tweaked the airplane with stall strips and counter-rotating props in an effort to make both wings stall at the same time.
I wrote about the twin training problem in Air Facts as well as in FLYING after I moved to that publication in 1968. I made many trips to Washington to virtually beg the director of FAA’s Flight Standards office to tone down the Vmc requirement. I was always rebuffed and sent away feeling like a private who had crossed swords with a colonel. Actually, I had better luck doing that when dealing with the real Army.
There is no question that a pilot’s skill will be critically tested if an engine fails in the first two or three minutes after advancing the power to take off. However, if an engine fails at any time during a flight the pilot is still faced with a single engine landing.
When fatal twin wrecks other than weather accidents were considered, two things topped the list. There were far more training accidents in twins than singles and there were far more fatal accidents in twins because of poorly flown engine out approaches than were found in the first two or three minutes of the flight. Yet the training concentrated on Vmc as it related to the climb right after takeoff. Guess what: Vmc is still there on approach.
When I instructed in twins, I always had students actually land the airplane with one prop feathered. That was criticized as being risky and one tower told me that if I insisted on doing it, they would treat it as an emergency.
To me it was a simple matter of my wanting anyone I trained in a twin to have been there and done that if ever faced with an actual engine-out landing. The first time was better with me than with family or friends or paying passengers along for the ride.
As the accident record evolved over the years, the training accidents became less of a factor, mainly because they had been such a huge problem and had gotten so much publicity that there were no surprises left there. The FAA finally backed away from suicidal Vmc demonstrations though not until some notable retirements from Flight Standards. Further, new-design twins had come along that were much more docile than that old ones.
The Beech Duchess was designed to be controllable in extreme circumstances and if you spun it, even with one engine shut down and the other one running wide open, it would not go flat and it would be easily recoverable. Video of all this made the rounds some years ago and it was quite impressive. The Duchess could actually have been approved for spins but Beech didn’t care to do that.
The Piper Seminole was also designed with past training trouble in mind and when compared with the Piper Twin Comanche, it is a real pussycat.
Along the way, I learned something else about twin misconceptions. My father and I had been operating a 250 Comanche that was replaced by a Twin Comanche in 1964. I transferred the insurance and was a bit surprised to see a substantial check to reflect a much lower hull insurance rate for the twin. Training accidents aside, was it really that much safer than the single?
I researched this, found out that it actually at flew higher risk than the single and I wrote about this in Air Facts. It was the first time anything like this had ever been mentioned and it, and much that was to follow, got me branded as being anti-twin. All I was really doing was showing that insurance underwriters were basing premiums on what they thought was true as opposed to what was actually true.
The industry misjudged twins, too, treating them as just another airplane. It was rather common in the 1960s to just toss someone the keys to a new type and if he caught them, he was checked out. Most twins didn’t have ignition keys so the checkout could be even simpler.
I flew a lot of twins with no real training or checkout and others with only the briefest exposure to the airplane. My Cessna 310 checkout took an hour, the Piper Apache was 45 minutes, the Aero Commander twin 30 minutes, and I checked myself out in the Beech Travel Air. The moment I was checked out in those airplanes I could start instructing in them. All the training, checkout and proficiency requirements for twins that exist today just weren’t around when the airplanes first came out.
I think the twins were forever tainted by those original problems that started in the late 1950s and peaked in the 1960s. It was slow motion but, much more recently, stringent training and experience requirements to be able to buy insurance on light twins have driven pilots away from the airplanes. The amount of liability insurance available might also be limited.
Of the small number of new twins sold today, only a few are airplanes that are likely used for business and/or personal travel. In fact, the number was 23 for last year. The Diamond DA-42s, which are diesel and not piston-powered, are not included in that 23 number because while I think they are probably sold more as trainers than transports, I don’t know that for a fact. Thirty-four of those were sold last year.
Because of the limited number being built and the fact that most twin training is now being done in professional training establishments like flight academies and educational institutions, we’ll never know how the modern twins would do if used like the twins in the good old days.
A lot of those old twins are still flying but most are not too active. The reality of the matter is that the cost of operating an old twin relates more to what it would cost new today than to any bargain price in the used market. To put that in context, a new G58 Baron is at or will soon reach $1.5-million.
What is wrong with twin pilots? Today, it is that they are disappearing. The remaining fleet of twins flies less and less every year and it will become ever less practical to keep the airplanes operating. The new twins are used largely in training pilots who want to fly the really big twins
On a personal note, I’d add that those twins sure were fun to fly. Back in the heyday they were the only way we could saddle up more than 250 or 300 horsepower. Doubling the horsepower was delightful to those of us who thought excellence in airplanes meant going as fast as possible making as much noise as possible and burning as much gas as possible. Times change. Darn.