I took this off a website I found through GOOGLE. There were many like it....just go in and type something like "accident rates single engine twin engine".
"In Canada, in operations with 58 Caravans, 14 PC12s and 2 TBM700s and with a fleet total since 1993 of approximately 175,000 hours, there have been two major engine shutdown occurrences – one due to a failure to install a fuel manifold locking plate in which the aircraft made a successful return to the field, while the other involved a forced landing in which there were no fatalities.
The Australian CAA study concluded that the single turbine was at least as safe as the piston twin in regard to engine-failure related accidents, and also stated that "forced landings at night are not necessarily as hazardous as might be expected and are mostly survivable: the fatal accident rate at night, while higher than by day, is only about 8 percent." The Australian CAA concluded that the probability of a fatal accident due to engine failure on a single-engined turbine aircraft was 0.07 per 100,000 hours, compared to "the best performing piston twins" rate of 0.15 per 100,000 hours. That says you’re at least twice as safe in a turbine single as in a piston twin.
UK CAA analysis of fatal accidents to aircraft of less than 5,700kg (12,500lb) on both private and commercial operations from 1985 to 1994 showed only 6 out of 166 (3.6 percent) were due to engine stoppage. The UK data included 4 fatals to light twins due to loss of control following engine failure or asymmetric power, compared to 9 fatals in single-engined aircraft, based on a sample of 8 million flight hours. Taking into account the probable number of hours of single and twin-engined aircraft in the sample, this indicates a far higher frequency of powerplant-related fatal accidents on twins than singles; (there are 7,500 singles on the UK register compared to 350 light twins).
Analysis by Robert E. Breiling associates for Pilatus Aircraft concluded that piston-engined general aviation aircraft were involved in 2.86 times more accidents than turboprop aircraft per 100,000 flight hours, when considering all causes.
The Swedish CAA study of the mid-1980s concluded that the fatal accident rate for single-turboprops, due to engine failure, was estimated at 0.13 per 100,000 flight hours. The study concluded that operations with SE turboprops are comparable with other commercial operations.
Cessna C208 Caravan fatals in the USA, 1985-1996 (2.6 million flight hours), were 0.56 per 100,000 hours; fatal accidents due to mechanical failures of the engine were zero. Of the five non-fatal accidents involving engine failure or shutdown, three occurred in 1990 and 1991 due to oil loss, because the oil cap was left off or improperly installed; a modification has been introduced to prevent such an occurrence. The remaining two were actual engine mechanical failures (scavenge pump and gas producer turbine failures).
Contrary to what one might imagine, 21.3 percent of accidents, and 20 percent of fatals in twin piston-engined aircraft in US operations occurred following engine malfunction or failure. In these cases, the accident occurred even though one engine was still functioning normally – indicating that the pilot was unable to control the aircraft following the engine problem.
The SETA SE IFR proposals include requirements for enhanced onboard systems and equipment, to make the pilot’s job easier, better maintenance programmes as well as operational limitations. Extra systems include dual electrical power supplies, an emergency electrical supply, two attitude indicators and engine health and usage monitoring. Crew training beyond that required for today’s twin licences is also suggested. Although the regulations do not require it, some Norwegian operators have a policy of a two-pilot crew for SE IFR, which would appear to be an eminently sensible, if costly, solution.
A further argument in favour of the single engined aircraft is its low stalling speed of 61 knots, imposed by long-standing certification regulations, which ensures a low touchdown speed, short ground run, and better survival probability in case of a forced landing.
Commercial need
Light piston twins designed in the 1960s and 70s are reaching the end of their safe working lives. Many operators make the point that performance of these aircraft on one engine at MGTOW has always been marginal; in difficult weather conditions, or at night, following engine failure, a high degree of piloting skill may be required to survive. Certain designs of the period had very limited, or even negative, climb capabilities on one engine. Systems, autopilots and avionics have become unreliable, and designed to lower standards than would be acceptable today, particularly in safety-critical areas; parts are hard to get and expensive, and safety-related repairs are far more frequently needed.
There is a compelling safety and economic case to replace the old clunkers with modern and reliable designs, represented by the new generation of turbine-powered singles. As one operator puts it: "we continue to fly on recycled junk." The market replacement need in Europe alone is huge, and could be served by Europe-based manufacturers Pilatus and Socata, to the benefit of the European aerospace industry, and by US-based Cessna and Piper. Undoubtedly, following operating approval, other designs would enter the market, further stimulating the general aviation sector.
Small outlying communities worldwide are coming to rely on air services for supplies, medical and other vital services, which today are provided at considerably higher risk levels by outdated piston twins. Is this really the intention of authorities that oppose approval of SE IFR operations? The SE turboprop would provide a higher level of safety and reliability, and be more economic to operate. As experience levels build up, reliability of the SE turboprop is likely to further increase.
Harmonisation of rules
The FAA and JAA agree on the need to harmonise regulations to create a consistently safe, seamless, worldwide transportation system. Clearly it is unsatisfactory for a tourist, for example, to take an IFR flight in a SE turboprop to a remote holiday destination, and then learn that such operations are considered unsafe by his home authority. This is the situation today.
There appears to be a misconception, notes the SETA document, that SE IFR is fine in the USA because the terrain and weather conditions are much more forgiving than in Europe. This conception is totally false, and in fact the weather in the US is far worse than in Europe in many areas. There are also numerous mountain ranges in the US, while population densities in the USA in many areas are similar to Europe.
Concern about little aeroplanes falling on people’s heads are equally unfounded – after all there are over 7,000 privately-owned singles in congested Germany alone, which can and do fly practically everywhere in IFR and VFR conditions, and they do not fall on people’s heads.
Experience in the USA, and elsewhere, has demonstrated that SE IFR in turboprop aircraft is safe. The bottom line is that a multi-engine piston operator has a higher probability of accident and fatality compared to the single turbine operator. This alone is reason enough to approve single turbine commercial IFR operations – for both passenger and cargo flights."
I apologize for the length of the article, but I thought it necessary to print it all....it reinforces my support for SE turbines.
John
