When Charles Lindbergh began planning one of the first truly long cross-country solo flights in 1927 everyone understood the risks inherent in a 3,000-mile journey in an airplane powered by a single 223-hp Wright J5 engine. Failure meant he’d probably end up as a shark snack. Luckily, he didn’t have the boss on board.
Aviation has progressed considerably in the past 77 years. Nonetheless, the thought of flying a single- engine aircraft for business still sends shivers up the spines of some people because the airplane has, well, only one engine and also because it is probably flown by only one pilot.
One East Coast Fortune 100 manager said he instituted a no-exceptions policy prohibiting employees from flying aboard a single-engine airplane for business purposes when he took over as aviation director two years ago. And only twin-turbine helicopters would be allowed to carry anyone from his company as well. When asked about his decision in light of the popularity of single-engine aircraft efficiencies tied to a proven powerplant, such as in many new turboprops, he said, “Single-engine aircraft may have evolved quite a bit over the past 20 years, but if that one engine quits, the likelihood of fatalities is great, I think. At least there is a backup if an engine quits on a twin.”
Another company told AIN, “Our company policy restricts single-engine operations to VFR helicopter operations. But all engines must be turbine. Fixed-wing operations, as well as IFR operations, must be flown by two pilots. This also holds true for any charter flights booked for our employees and also applies to our employees while aboard business-associate aircraft while on company business.”
Greg Mahanna, aviation department manager for a privately owned Gulfstream IV, said, “When we charter, we insist on two pilots and a list of other audit requirements when the principal is on board, even in a King Air, for example. We also require two pilots in helicopters, which must be twin-engine, turbine machines. I have chartered a Baron for the principal’s yacht captain and that was flown single pilot; however, the principal was not on board and will never board a piston-powered aircraft. Most of the flight departments I know also follow the two-pilot requirement.”
Despite the anxiety of some corporate operators, single-engine Part 135 passenger-carrying operations are legal in the U.S. In Europe, however, the jury is still out, to the consternation of single-engine aircraft manufacturers. Sources say European charter certification is stalled because of individual differences among some EU members, namely Germany, Italy and the UK. A Pilatus spokesman said the company hopes to see a break in that logjam before year-end.
Regardless of the twin-engine safety debate, the number of single-engine turboprop aircraft delivered, such as the Cessna Caravan, Pilatus PC-12, Piper Meridian and EADS Socata TBM 700, has actually outpaced the number of King Airs, according to the General Aviation Manufacturers Association (GAMA). In the first half of this year, the four companies delivered 72 aircraft, most of them to U.S. customers. Single-engine turboprops represented 41 percent of the turboprops built around the world. In this same period, Raytheon, the only twin-engine turboprop manufacturer in the U.S., delivered 27 King Airs–seven 90s, a dozen 200s and eight 350s.
The Accident Record
The single- versus twin-engine and single-pilot versus two-pilot debate is an old one and, not surprisingly, corporate PC-12 pilot Todd Nelson said, “Planning for a single-engine IFR flight is not much different from the thought process that goes into planning a multi-engine IFR flight. In some ways the planning is simplified because having only one engine narrows your choices.” While the manufacturers of single-engine aircraft concede there are some safety risks inherent in having only one engine, the statistics show that engine failures in twin-engine aircraft, even with two pilots, do not necessarily lead to successful outcomes.
According to Bob Breiling, of Robert E. Breiling Associates, “Flying any turbine aircraft in a single-pilot operation increases the odds of an accident by 50 percent alone. There were 127 accidents in single-engine turboprop aircraft in 2003 with 52 fatalities. The majority of fatalities–39–were in Cessna Caravans, a type often flown by relatively inexperienced pilots. In other operations, Piper’s Meridian experienced 14 accidents and seven fatalities; the TBM 700 had 12 accidents and four fatalities; and the PC-12 experienced seven accidents and two fatalities. “Most of the fatal accidents in these aircraft were not related to engine issues,” Breiling said.
Breiling added, “There have been 125 accidents in Citations between 1972 and 2003. Thirty of these accidents befell aircraft certified for single-pilot operations and involved 13 fatalities. Essentially, that means 43 percent of the single-pilot accidents were fatal, versus 24 percent for Citations operated with two pilots.” One variable that makes tracking single-pilot figures difficult is that it is nearly impossible to accurately determine how many single-pilot-certified aircraft are actually being regularly operated that way.
Don Taylor, v-p of safety with Eclipse Aviation, added it is important to consider these accidents in the context of the company that operates the aircraft, such as a freight carrier using a Citation to fly boxes in the middle of the night with one possibly tired pilot.
When Sandy Rand, president of Bridgeport, Conn.-based Rand Insurance (his company does not insure aircraft), chose a TBM 700 to replace his Piper Mirage, the single- versus twin-engine issue was very much on his mind, since he’d experienced a complete engine failure on the Mirage after takeoff from Nantucket. Rand was able to glide the airplane back to the airport safely. According to factory figures, after a high-altitude engine failure in a PC-12, for example, the aircraft can glide as far as 70 miles and still touch down at speeds of between 50 and 60 knots.
Rand is not multi-engine rated but considered picking up the ticket before he chose the Socata. “I really had to think hard about how I was going to use the airplane. Certainly there is a margin of safety in a twin-engine airplane that has value, but if you don’t make the right decisions when one engine quits, you’ll still be in trouble. When you fly a single-engine airplane, you must have options. I feel I can manage the risk in a single to a very acceptable level.”
Asked how passengers feel about flying in a single versus a twin, Rand said, “The passengers don’t look at the airplane. They don’t know enough about it. They look to me. They trust me.” Adam Webster, president of AirWebster, a charter brokerage company, explained that while many pilots have expectations about the safety of single-engine and twin-engine airplanes, passengers don’t see things that way. He noted, “While a single-engine turboprop like a PC-12 might be a hard sell to some corporate types, there are plenty of people coming to the market without any preconceived notions about what an airplane should or should not be.”
Nelson said, “If a passenger asks about the safety of single-engine operations, I generally start out by explaining the PT6 and its exemplary safety record. This usually leads to the “aren’t more engines better?” conversation. Statistics show that the accident rates for turboprop singles and turboprop twins are not all that different, roughly two per 100,000 hours.
However, the bottom line is that turbine engines just don’t fail all that often. The PT6 has an in-flight shutdown rate of about one in 250,000 hours.”
Weighing the Costs and Benefits
All too often, any discussion of single-engine flight, whether in a Cessna 172 or a Piper Meridian, focuses solely on safety. And while passenger well-being is an important consideration, the economics of a single-engine airplane must be a part of the decision as well. Certainly, the economy of operating a single-engine aircraft is readily apparent; overhauling one engine costs less than overhauling two. Nelson adds, “Selling the efficient and effective side of this question to passengers is not all that difficult. Pilatus claims that a direct operating cost of about $345 per hour and the airplane’s ability to operate out of small airports and from unimproved surfaces cover the efficient and effective inquiries, respectively.”
Al Hoyt, CEO of Western Aircraft, a former Caravan dealer who now sells and charters PC-12s in Boise, Idaho, explains, “When you’re the guy paying the bills, as many of our owners are, it’s much easier to feed one engine than two.” Hoyt believes strongly in the single-engine concept. “I don’t think we could have sold 88 airplanes from Boise in the past nine years if this wasn’t a solid airplane.”
Hoyt believes there will be customers he’s never going to convince of the attributes of a single-engine airplane versus a twin probably because, “Some pilot had an engine failure in a King Air once and is not open-minded about anything else. If people tell me they just can’t imagine flying with fewer than two engines, I tell them to call Raytheon.”
When TAG Aviation brought a PC-12 into its aircraft management ranks, the decision was easy for the financial institution owner, which also operates a Falcon 50. “They needed a more efficient aircraft for short trips in the Southeast and the PC-12 was clearly it,” said a company official.
Alpha Flying in Manchester, N.H., operates a fleet of 14 PC-12s in a fractional operation called PlaneSense that expects to log 10,000 flights this year. When George Antoniadis, the company’s CEO, developed PlaneSense, “We were after an efficient, modern turboprop aircraft for a more regional demand. Most jets simply did not fit our model. While the King Air was a natural choice initially, the aircraft did not deliver the economic numbers we needed.
“The only modern aircraft that worked for us was the PC-12. We fly them with two pilots because we want to deliver a level of service and comfort commensurate with the other fractional operators. We did not feel we could do that with one pilot.” To maintain a level of safety consistent with other aircraft in its fleet, TAG operates its PC-12 with two pilots aboard as well. “We believe having a second set of eyes in the cockpit is important,” the TAG official said.
Rand asserted, “Most people believe what they believe about single- versus twin-engine airplanes and will not change their minds easily. I think the argument still comes down to what you want out of an airplane. There are a lot of people buying single-engine turboprops who might have bought twins if cost was not such a huge factor.”
Nelson noted, “The statistics speak for themselves: single-engine turboprops are as safe as, if not safer than, their multi-engine brethren. Put the engine up front, and with the money saved in operating cost and initial purchase price, invest in regular and varied training because it is more likely that the pilot, not the engine, will malfunction.”
Antoniadis believes part of the reason for the success of his company’s single-engine aircraft operation is that “Most of our potential clients are sophisticated buyers.” And while many established companies scoff at the concept of putting executives in single-engine aircraft, he was actually “surprised at how open many companies have been to the concept.” Antoniadis added, “I’ll never really know how many sales calls we’ve missed because we fly single-engine turboprops, but our growth rate is certainly very healthy.”