However, MyJets is aware of the concern many people may have about single engine planes in general even though turboprops are jet engines behind a propeller and thus have a reliability comparable to a jet plane. 

The choice of the TBM 700 was not solely based on its spaciousness, comfort and cost effectiveness, it was also selected for its exceptional safety records. These safety records are well documented.

Modern aircraft have an enhanced reliability due to their newer design, and state of the art powerplants and avionics.

MyJets management has extensive experience in worldwide flying in all weather conditions of single engine planes and of TBM 700.

This fact alone and  the exceptional safety record of the TBM 700, added to its superior quality of design and manufacturing, make the TBM 700 ideally suited for the kind of missions (less than 500 miles) MyJets is developing.

Socata the manufacturer of the TBM 700 is part of the EADS group who manufactures the Airbus commercial airliners and the Ariane rocket.

The safe operation of an aircraft is dependant on the quality of training of its pilots.

MyJets pilots are all factory trained by Socata representatives in the country MyJets planes fly.

The TBM 700 is a world class turboprop, with an impressive safety record. and many articles have been published over the years in reference to the safety of the three major single turboprops in existence today.

A few basic facts before the articles:

One engine allows landings at lower speed, thus on a shorter runway and with an increased safety. 

The seriousness of a crash is proportionate to the kinetic energy (G force), which increases as the square of the speed.  

A TBM 700, single engine plane, without its engine running, is still flying at 61 Knots (stall speed). At that speed, unless the plane hits a wall straight-on, the plane can stop in less than 50 feet without generating lethal G forces.

An old adage in aviation says: " in a twin, the second engine is here to lead you to the site of the crash" and that is at a much higher speed than with a single. At 71 knots the G force is double than at 50 knots and triple at 87 knots.

Engine failure is rarely the major cause of fatal crashes in single or twin engine planes alike. 

The major cause of crash from small single to wide body airliner is still "pilot error".

In summary, MyJets investors and customers can have confidence in MyJets program and the quality of the aircraft/pilot  teams developed by MyJets. You may contact  Marcel R. Georgi, CEO of MyJets, Inc. at marcel@myjets.net to ask any questions you may have about the attached materials or the MyJets program.

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A selection of safety related articles follows:

1. "Two Engines Are Better Than One, Right?" by Oliver Sutton;

2. "Single- and twin-turbine accident rates similar" by Gordon Gilbert;  

3. " Single Turboprop Powerplant Aircraft Reliability.

Two Engines Are Better Than One, Right?

by Oliver Sutton

Following a considerable lobbying effort, under the banner of the Single Engine Turboprop Alliance (SETA), it seems likely that SE commercial IFR operations within Europe will at last become a reality.

This article first appeared in INTERAVIA, BUSINESS & TECHNOLOGY No. 634 in September 1999. It is made available on this site by courtesy of the publisher, Aerospace Media Publishing SA. AMP may be contacted through http://www.aerospacemedia.com, or via e-mail

Two engines are better than one. Especially on a dark and dirty night, flying over mountainous territory - right? Well, not always, and certainly not if you take a closer look at the accident statistics. This apparent contradiction looks set to create new opportunities for single-engine utility aircraft manufacturers.

In Europe, JAA regulations OPS 1.525 as currently written prohibit the use of single-engine aircraft for any commercial operations, whether passenger carrying or for cargo flights, at night or in Instrument Meteorological Conditions (IMC). This position reflects an ICAO standard, written in 1948 with then-unreliable reciprocating engines firmly in mind, which states that SE aircraft shall only be operated in conditions of weather and light that permit a safe forced landing to be executed in the event of engine failure.

The FAA has a long history of authorising SE IFR and night operations in both reciprocating and turbine-powered aircraft, subject to aircrew training and experience levels. Prior to 1978, operations were authorized in IMC or on top of a ceiling as long as VFR conditions existed below cloud , providing a buffer zone for an eventual forced landing. In 1978 regulations were revised to limit passenger carrying operations in SE aircraft to 15 minutes in IMC after departure, or if unforecasted IMC was encountered. The aircraft also had to be able to descend under VFR if the engine failed. This was generally seen as an unsatisfactory rule.

In May 1998 regulations were further revised to expand SE operating authority, provided additional maintenance and equipment requirements were met. Many factors influenced the decision, including data showing the Cessna C208 Caravan turboprop to have a high level of reliability, Canada's positive experience with SE IFR, and a significant CFIT problem in Alaska, particularly, as a result of continuing VFR flights into deteriorating IMC conditions. In Alaska, pilots were filing for a VFR commercial flight, aiming to stay below, or in the clear on top. Instead, they ran into deteriorating weather conditions, pushed on to gain their crust of bread, and ended their careers as a CFIT statistic. The situation was rightly judged by the authorities as highly dangerous. The expanded SE IFR authority was felt to provide a significantly higher level of safety.

Today there are some 50 countries worldwide that permit SE commercial IFR operations, including a number approving cargo only operations in Europe. The challenge in Europe is to agree a harmonised rule. To this end, in 1995 the JAA set up a working group, which put out an Advance-Notification of Proposed Amendment (A-NPA), suggesting removal of the restriction on SE commercial IFR operations, with a number of additional, and many maintain impractical, operating conditions and minima. AECMA maintains these proposals have been evolved from JAA ETOPS rules applicable to large aircraft, and which are overdemanding.

The original working group discussions and proposals included approval for SE IFR passenger operations, but this important detail appears to have got "lost" in the mists of time. The WG requested comments on the A-NPA from interested parties, including authorities, associations, operators and manufacturers. Their replies have recently become available to INTERAVIA.

In Europe the issue has been an emotive one for years. National certification authorities have been divided into two camps, those that were prepared to approve SE operations, and those that wouldn't consider it at any price. The Scandinavians, and France, went for early approval, but restricted operations to cargo only, while the British CAA, supported by the British Airline Pilots association (BALPA), and the SBAC, remained ferociously opposed. Today the British contingent finds itself in a minority of one.

It is perhaps worth noting that BALPA had been equally ferociously opposed to the concept of ETOPS, where twin-engined airliners carrying hundreds of passengers were expected to fly for up to 180 minutes on one engine following failure of the other engine. Today ETOPS is an every day fact of life. BALPA's case against SE IFR is focused on the possible consequences on the ground of a forced landing at night in highly-populated Europe, the difficulty of executing such a landing, and the need for more detailed research. The UK CAA wants significant enhancements of systems integrity and capability, operational limitations and pilot training before it could reconsider its position. The SBAC position reflects the standpoint of UK-based light twin manufacturer Britten-Norman.

Until recently, other authorities appeared content to follow the ICAO rule, effectively getting themselves off the hook. The pressure for single-engined commercial operations in Europe was minimal, since there was a plentiful supply of late-model piston and turbine twins, and the turbine single had not yet been invented. Today pressures of economics and competition are threatening the survival of small transport and charter operators flying now-elderly twins, and many are looking to the lower operating costs that turbine singles offer. Additionally the supply of good, late-model piston twins has long dried up.

It was just a year ago that we took an in-depth look at two popular utility aircraft , Cessna's hugely successful Caravan workhorse, over 1000 of which are now in service, and the Pilatus PC12 (see INTERAVIA N. 622, July/August 1998, p. 33), which provides close to the performance and capability of a King Air 200 twin turboprop on just one engine. On the subject of the approval of these aircraft for SE commercial IFR operations, we noted the compelling ICAO argument for "a fare-paying passenger to have a right to the same safety level irrespective of what aircraft he is travelling on". And we continued "and that can clearly never be the case in a single-engined aircraft."

We reckon that we are going to be proved wrong. Following a considerable lobbying effort, under the banner of the Single Engine Turboprop Alliance (SETA), set up by manufacturers of single-engined turbine-powered aircraft, including Cessna, Pilatus, Socata and Piper, and other interested parties, the JAA is now forming a new working group to take account of the comments received to the earlier A-NPA and come up with recommendations. With the overwhelming level of support indicated, it seems likely that SE commercial IFR operations across the EU will at last become a reality , at least for cargo flights, initially, to gain confidence levels.

The SETA lobby has built up a convincing case for the doubters, consulting authorities, associations, small operators, distributors and manufacturers across the world in its quest to change a mindset.

According to SETA the justification for SE IFR, at least for cargo initially, lies in three major categories: the Safety case; the Commercial need; and International harmonisation of rules. Wider issues include the approval of the carriage of passengers in IFR, though certain authorities support the carriage of passengers from Day One.

The Safety Case

The SETA proposal considers that the safety target for the operation of SE aircraft at night or in IMC should clearly exceed what has been achieved in recent years with small twins. It then points out that US, Canadian, Australian and other authorities, and the JAA Working Group, have demonstrated the ability to meet this target. Propulsion-related accidents are a minority of total accident , under US FAR 135 operations 1981-1990, 18 percent. The perceived concern of single engine failure is not the most significant contributory cause of accidents. Out of 28 accidents to Caravans, worldwide, in the period 1985-98, no fewer than 14 were due to CFIT. Surely that should be telling something to the pilot licensing, rather than the certification, authorities?

Accident rate per 100,000 flight hours

US FAR 135

Scheduled Service 1981-90 C208

1985-93

NTSB 1979 report

ME piston propulsion All causes related Propulsion related Propulsion related

Accidents 1.21 0.22 0.30 1.70

Fatal Accidents 0.30 0.06 0.07 0.41

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.

SIDE STORY: Engine Condition Trend Monitoring

ECTM, developed by Pratt & Whitney Canada, is essentially a three part process:

1. In-flight data may be gathered by the pilot or by an automatic recorder. Accuracy of the data is dependent upon the accuracy of the readings taken and recorded. Data includes compressor speed, torque, IAS, prop speed, inter-turbine temperature, fuel flow, indicated outside air temperature and pressure altitude.

2. The data is mathematically converted to ISA conditions SL, and compared to a mominal engine model to produce deltas, which can be viewed on screen or printed.

3. Analysis of the trends forms the basis for the "on-condition HSI" concept of hot section inspections, and for other maintenance.

The use of ECTM will increase safety, decrease HSI cost, reduce down time and minimize flight aborts, maintains Danish Engine Trend Analyzing (DETA), which currently "keeps an eye on the trend" of some 25 aircraft. Engines covered include the PT6, PW100, PW300, PW500 and the JT15D series.  

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Single- and twin-turbine accident rates similar

by Gordon Gilbert

In the aftermath of July's well publicized engine-out ditching of a Pilatus PC-12 in the Pacific Ocean off the coast of Russia, industry observers are asking how this and other recent accidents have affected the statistical reliability of single-engine turboprops and if sales of these aircraft are suffering.

Although production-built single-turbine airplanes used for business flying typically do not have the same speed, load capability or systems redundancy as twin-turbine airplanes, they have amassed a comparable safety record, according to statistics through last year compiled by accident analyst firm Robert E. Breiling Associates of Boca Raton, Fla.

Breiling reports U.S. turboprop-singles have had 1.99 total accidents and 0.80 fatal accidents per 100,000 flight hr compared with 2.37 and 0.83, respectively, for U.S.-registered turboprop twins. These figures cover the period from initial aircraft certification through last year. Last year the statistical reliability of single-engine turboprops was even played up by Pilatus in its marketing of the PC-12.

While accident rate statistics seem to back up that claim, the actual number of single-engine turboprop accidents is increasing as the fleet gets larger. This year to date, the NTSB reports that there have been 10 accidents, five of them fatal, involving four production-certified single-engine turboprops: the Cessna 208 Caravan, Piper PA-46-500TP Meridian, Socata TBM 700 and Pilatus PC-12.

Nine of the 10 accidents are still under investigation, seven of the accidents were in Cessna 208s (by far the most numerous of all turboprop singles, with close to 1,300 in operation), and engine failure has definitely been determined as a factor in four accidents, (April 26, July 6, July 8 and July 10) none causing critical injuries. The Safety Board determined the January 31 crash of the Cessna 208 on floats was caused when the airplane hit a swell during a water landing. All production turboprop singles are powered by the Pratt & Whitney Canada PT6 series.

Engine Problems

A Caravan flying for FedEx made a forced landing April 26 after an engine failure. The pilot (not injured in the accident) said that during climbout the airplane's engine "spooled down, slowly and smoothly, like a loss of torque or the propeller going to feather." Later, an examination of data from the power analyzer recorder system revealed that during the most recent takeoff the engine exceeded its torque limit of 1,980 ft lb for 99 seconds. The peak torque value over that duration was 2,649 ft lb.

On July 6, a Caravan on a repositioning flight operated by Maxfly Aviation ditched into the Atlantic Ocean 20 mi east of Fort Lauderdale, Fla., following loss of engine power. According to the pilot (who was not hurt), the airplane was cruising at 6,500 ft when the engine lost power and came to a "screeching halt." The propeller made a "chow, chow, chow" noise, turned three times, stopped and feathered.

In the July 8 PC-12 ditching, the pilot reported that the airplane was in cruise at 26,500 ft when he felt a vibration followed by a rapid increase in the engine's turbine temperature indication (TTI). He reported that the TTI reached 1,144 deg C, at which point there was a compressor stall. He shut down the engine, feathered the propeller and entered a power-off emergency descent. After spending 15 hr in a life raft, the pilot and all three passengers were safely recovered some 60 mi from the Russian coast in the icy Sea of Okhotsk.

Two days later, on July 10, a Cessna 208 of Bolivian registration (CP-2395), was substantially damaged during a forced landing following a loss of engine power during climbout from the La Paz International Airport in Bolivia. The pilot, the copilot and 11 passengers were injured. The flight crew reported a loss of engine power approximately six minutes after takeoff.

In the U.S., more than 70 percent of PC-12 sales are to owner-pilots for personal and business flying. As might be expected, just the opposite is true for the Caravan, where 70 percent of its users are small package commercial operators, according to director of Caravan sales for Cessna John Doman. "In our experience with the Caravan,which has more than 15 years of service under its belt, flying in all sorts of different conditions,it has established an enviable safety record. The PT6 is a legendary powerplant in terms of reliability. So our reaction from the marketplace is one of acceptance of the safety inherent in the turbine single."

A lot of Caravan air-freight customers are moving up from piston twins such as Beech 18s, Queen Airs, Navajos and Cessna 402s. "Statistics and just common knowledge tell you that a single-turbine airplane is going to be a safer, more reliable piece of machinery than the piston twin," Doman said.

Doman said Cessna does not actively market the Caravan to the U.S. air-taxi industry. He described that position as a "corporate decision," not based on any accident or incident history. The airplane by regulation is permitted to fly air taxi, including carrying fare-paying passengers in IMC, but Doman said Cessna over the years has become "very sensitive" to product liability in the U.S.

There are many air-taxi Caravans in operation outside the U.S., "But if someone were to come to us for a new Caravan for flying paying passengers between Chicago and Minneapolis, we would respectfully decline the sale." Overseas, however, Cessna encourages sales to this market. And that market potential is just waiting for some promised rulemaking relief.

For the last five years Cessna has been working with other airframe manufacturers as a member of the Single Engine Turbine Alliance (SETA) to get the JAA to change the requirements in Europe to allow single-turbine IFR commercial operations. Such operations are currently prohibited for both carrying cargo and fare-paying passengers. "We think that the way things are headed, we should see a change by perhaps the end of this year," Doman said.

A spokesman for Piper Aircraft in Vero Beach, Fla., echoed the statements on the quality, excellence, reliability and safety perceived by prospective and new owners of single turboprop airplanes. Indeed, P&WC statistics show the time between unplanned removals for the PT6 family as occurring once in every 142,817.14 hr and the time between in-flight shutdowns to be one in every 250,000 hr.

Aviation International News is a publication of The Convention News Co., Inc., P.O. Box 277, Midland Park, NJ, 07432. Copyright 2001. All rights reserved. Reproduction in whole or in part without permission from The Convention News Co., Inc., is strictly prohibited. The Convention News Co., Inc., also publishes NBAA Convention News, HAI Convention News, EBACE Convention News, Paris 2003, Dubai 2001, Asian Aerospace 2002, Farnborough 2002, AIN Reports and AIN News Alerts.

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The following safety information is summarized from the contents of a report prepared by:

ROBERT E. BREILING ASSOCIATES, INC.

765 N.E. 35th Street, Suite B

Boca Raton, FL 33431

(561) 338-6900

SINGLE TURBOPROP POWERPLANT AIRCRAFT RELIABILITY

For PILATUS BUSINESS AIRCRAFT LTD.

August 2000

Summary/Findings

Powerplant Reliability Comparative Data - Five Year Average. 1992-1996 (Data is based on information available from NTSB and FAA sources). 

Accidents per 100,000 hours by major aircraft type, 5 year average 1992-1996 

Single engine reciprocating powered aircraft 9.26 

Multi-engine reciprocating powered aircraft 5.68 

Multi-engine turboprop powered aircraft 4.34 

Single engine turboprop aircraft 1.46 

Percent of general aviation fixed wing aircraft accidents attributed to power loss - all causes - 5 year average, 1992-1996

Single engine reciprocating powered aircraft 33.5%

Multi-engine reciprocating powered aircraft 27.6%

Multi-engine turboprop powered aircraft 8.0%

Single engine turboprop aircraft 0%

Percent of general aviation fixed wing aircraft accidents attributed to power loss due to mechanical, maintenance, design, manufacturer causes

Single engine reciprocating powered aircraft 14.4% 

Multi-engine reciprocating powered aircraft 8.9%

Multi-engine turboprop powered aircraft 4.0% 

Single engine turboprop aircraft 0%

Accidents per 100,000 hours due to power loss for mechanical/maintenance/design/manufacturer (based on Commercial and Air Carrier operation data compiled by the FAA)

Single engine reciprocating powered aircraft 1.33

Multi-engine reciprocating powered aircraft 0.51

Multi-engine turboprop powered aircraft 0.17 

S/E turboprop aircraft excluding agricultural aircraft 0

Powerplant shutdowns per 1,000 hours (Commercial/Air Carrier data) Average of selected powerplants, 1997

Reciprocating powerplant average 0.208

Turboprop powerplant average 0.041

Selected Aircraft Accident Analysis - Certification through 1999 - U.S. Fleet

Piper Malibu(sic) Cessna Caravan Socata TBM700 Pilatus PC-12

Certification Date 1983 1984 1988 1994

U.S. Fleet Size 749 821 74 133

Accidents 79 59 5 1

Fatal Accidents 25 27 1 0

Accidents due to

powerplant

malfunction / failure 14 2 0 0

Cumulative flight

hours 1,100,150 3,145,272 161,406 134,234

Accident rate

per 100,000 hrs. 7.18 1.88 3.10 0.74

Fatal Accident rate

per 100,000 hrs. 2.27 0.86 0.62 0

Power loss accident rate

per 100,000 hrs. 1.27 0.064 0 0

*1 non-U.S. registered PC-12 experienced an accident due to powerplant loss due to mechanical malfunction / failure

 Conclusions:

Based on the review and analysis of accident data involving multi and single reciprocating and turboprop powerplant malfunction / failure accidents and analysis of the various powerplant reliability data available, a single turboprop powered aircraft, with adequate backup systems provided in it's design, will be more reliable, involved in fewer powerplant malfunction / failure related accidents than that of single or multi reciprocating powered fixed wing aircraft and comparable to the reliability of a multi-turboprop powered aircraft. 

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