Single Engine turboprop crossing the North Sea
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Having been a founding member of the original JAA SEIMC Working Group and attending many but not all meetings in NL I do perhaps have a good insight into the reasoning behind the safety issues.
At the first meeting the UK CAA, German LBA and many other NAAs stated that they were totally opposed to any form of Commercial SET operations as they were deemed to be unsafe. This was before the agenda and ground rules had been discussed. The CAA rep then retired from the Authority but left his stamp on the team. Many of the EU NAAs were scared stiff of the CAA and followed their opinions blindly. The very wise Graham Skillen from the CAA headed their contingent but was bound by instructions from above. We analysed every accident to an SET aircraft to determine whether or not it was engine related, The CAA wanted to classify one 'unexplained' accident as an engine failure until I pointed out that I knew that the pilot had taken his life. The experienced man from the French BEA who wrote the accident report stated that he thought that my comments were closer to the truth than their official report. Some days it was tough battle as many of the officials didn't want to introduce possible liabilities to their NAAs. The late Ronald Ashford ex CAA and JAA was a good Chairman.
At the subsequent meetings with 3 from the CAA we discussed and with difficulty set desired safety targets such as the all cause in flight shut down rates for the PT6 and aimed for a target of not more of 1 engine failure per 6 per million engine hours, the rate is now close to becoming less than 4 per mil. This includes ALL engines not those just maintained to Commercial standards but included engines in 3rd world operations and on extended tbo some up to 8000 Hr and some dodgy engine overhauls. No note was taken of the number of cycles run. As stated the accident with 17 fatalities was caused by water in the fuel it would have happened if the aircraft had 2,3 or 4 engines.
The reliability of the engines cover ALL engines and ALL types of operations, NOT just those maintained to commercial standards. Many of the Caravans are used for bush and para operations and often flown by low time hour building pilots who want turbine time and little or no ground school training. The maintenance standards required and initial and recurrent training for the pilots are much more rigorous than for private operations.
Comparing existing statistics with those likely under the proposed regulations is the equivalent of stating the safety standards of the London Black cabs but including the accident stats from UBER and minicabs. The new regulations are designed to improve the already good safety record, let the public make the decision.
The only engine under consideration was the PT 6 and the only aircraft The TBM 700, Pilatus PC12 and the C208 all of which have an emergency power lever so if there is a failure of the FCU then unlike in a King Air the pilot still has power available. New SET aircraft or modified older aircraft will have to provide safety substantiation for them to be considered for SET commercial operations.
The other criteria was the Fatal Accident rate (all causes). From the statistics available The rate is equal to that of MET aircraft but now trending to be better. The rate for MEP is unknown as the hours are not reported but off airport landings in avgas powered aircraft sadly often involve fire and most do not have a 4 point harness for the pilot. The SET aircraft being designed to later certification standards and having a lower impact and touchdown speed the passengers in SET aircraft are much more likely to survive an off airport landing. The stats confirm this. Sadly many of the pilots who did not survive such landings had failed to fasten their 4 point harnesses.
The QuinetiQ report is badly flawed and was not subjected to interested party comments and peer review as the JAA and the EASA had no experts or peers to review it. The CAA had NO experts in house as they didn't permit such operations so didn't know, they did have some enlightened people but the policy was Not in my backyard still prevailed from the top down? The staff at QuinetiQ did not even bother to accept an invitation to visit a local commercial operator of SET aircraft nor attempt to discover the standards to which the 'Commercial' operators of many PC12s and TBMs operated to I gave them the names of the contacts. Ill spent JAA money for a technically thin but well padded report.
The requirement for always being within 15 minutes out of gliding distance of a suitable landing site was introduced by the CAA when I was not at the meeting. The Spanish had permitted operations from the mainland to the Balearics. The rule was not thoroughly thought through from an operational point of view as in that they state that it can only be used once per flight. They assumed that the engine always gave no warning of failure, seized instantly and that the aircraft was then at best gliding speed. They said that on airways it was illegal to convert the energy you had to altitude and thus increase the distance one could then glide. When ETOPS was introduced there was the 90 min wet footprint rule that traveled with the aircraft along the route, then increased to 180 and I think now 270 min available or more as a continuous risk period. These extensions are based on the proven in service reliability of the engines. There has not been any increase in the risk period for SET aircraft that was set some 10 years ago, yet the hours flown has increased from probably 8 million to over 20. The EROPS risk is now surely not the failure of an engine or systems but the landing at a frozen airport where the aircraft has to be evacuated because of smoke or fire and the life threatening freezing and wind chill conditions for 350+ passengers. You cannot get them to climb back up the slides and most airports don't have heated buses available to transport them to the terminal. The UK CAA introduced this face saving, not life saving proposal 15 minute proposal, but then none of 'their experts' had actually flown a civilian SET and were not aware of commercial SET operations as they were not permitted.
Some 10 years ago there were more SET aircraft operating in Europe than there were piston twins in commercial operations circa 270. These SET aircraft were not falling out of the sky due to engine failures landing on schools or orphanages, no they just got on with their job of safely transporting passengers and freight from A - B in all weathers, just we can see everyday on FR24. The vast majority were flown by private pilots not by commercially trained pilots and nor were the aircraft maintained to the proposed rigorous standards.
Yes there have been accidents and fatalities but if you analyse them in depth you will often discover that the pilot was attempting to operate the aircraft outside of the approval status shown in the limitations section of the approved Flight Manual: Often too high, too fast, not checking that they are pressurised, not de-icing the frosty wings, grossly overloaded, out of C of G. Nothing new there they do the same in twins. If an engine fails on takeoff in in a King Air or a misjudged SE Go around sadly many of us have heard the thump and seen the sickening pall of black smoke. Pilatus have proven that a well trained current pilot suffering an EFATO can if prudent turn back at a height of 750ft. I believe that the TBM has a fatal accident rate due to engine failure of ZERO.
Modern flight information data such as Skydemon and others can show you the gliding distance at any point in flight and importantly in planning the flight. Later aircraft have EFIS with Flight Planning on the IPad.
Will the sky be full of Commercially operated SET aircraft and the older twins gone to the scrap heap? Not in my opinion, the market will find its own level, there will always be the place for light piston twins, cabin class twins as well as SET aircraft. So far as over-water operations are considered a PC 12 was successfully ditched in the Pacific and so have some Caravans for they have big doors. I would not like to be scrambling to escape underwater with 9 others from some of the newer small 9 seat high wing light twins coming on the market. Islanders and Commanders don't ditch well.
Commercial customers demand reliability, goods or people transported from A to B on time on a regular basis often over great distances and if you operate old turbine twins such as Commanders, LET, MU2 and Metros or piston twins such as Aztecs, Navajos or Cessnas then unless you have spare aircraft at least 5 for every 3 needed in service then you will go bust.
Please be open minded about the development of SET operations but unless you have thoroughly evaluated both the aircraft, the equipment, the training required and the proposed regulations please don't shoot from the hip and make unsubstantiated or emotional comments.
At the first meeting the UK CAA, German LBA and many other NAAs stated that they were totally opposed to any form of Commercial SET operations as they were deemed to be unsafe. This was before the agenda and ground rules had been discussed. The CAA rep then retired from the Authority but left his stamp on the team. Many of the EU NAAs were scared stiff of the CAA and followed their opinions blindly. The very wise Graham Skillen from the CAA headed their contingent but was bound by instructions from above. We analysed every accident to an SET aircraft to determine whether or not it was engine related, The CAA wanted to classify one 'unexplained' accident as an engine failure until I pointed out that I knew that the pilot had taken his life. The experienced man from the French BEA who wrote the accident report stated that he thought that my comments were closer to the truth than their official report. Some days it was tough battle as many of the officials didn't want to introduce possible liabilities to their NAAs. The late Ronald Ashford ex CAA and JAA was a good Chairman.
At the subsequent meetings with 3 from the CAA we discussed and with difficulty set desired safety targets such as the all cause in flight shut down rates for the PT6 and aimed for a target of not more of 1 engine failure per 6 per million engine hours, the rate is now close to becoming less than 4 per mil. This includes ALL engines not those just maintained to Commercial standards but included engines in 3rd world operations and on extended tbo some up to 8000 Hr and some dodgy engine overhauls. No note was taken of the number of cycles run. As stated the accident with 17 fatalities was caused by water in the fuel it would have happened if the aircraft had 2,3 or 4 engines.
The reliability of the engines cover ALL engines and ALL types of operations, NOT just those maintained to commercial standards. Many of the Caravans are used for bush and para operations and often flown by low time hour building pilots who want turbine time and little or no ground school training. The maintenance standards required and initial and recurrent training for the pilots are much more rigorous than for private operations.
Comparing existing statistics with those likely under the proposed regulations is the equivalent of stating the safety standards of the London Black cabs but including the accident stats from UBER and minicabs. The new regulations are designed to improve the already good safety record, let the public make the decision.
The only engine under consideration was the PT 6 and the only aircraft The TBM 700, Pilatus PC12 and the C208 all of which have an emergency power lever so if there is a failure of the FCU then unlike in a King Air the pilot still has power available. New SET aircraft or modified older aircraft will have to provide safety substantiation for them to be considered for SET commercial operations.
The other criteria was the Fatal Accident rate (all causes). From the statistics available The rate is equal to that of MET aircraft but now trending to be better. The rate for MEP is unknown as the hours are not reported but off airport landings in avgas powered aircraft sadly often involve fire and most do not have a 4 point harness for the pilot. The SET aircraft being designed to later certification standards and having a lower impact and touchdown speed the passengers in SET aircraft are much more likely to survive an off airport landing. The stats confirm this. Sadly many of the pilots who did not survive such landings had failed to fasten their 4 point harnesses.
The QuinetiQ report is badly flawed and was not subjected to interested party comments and peer review as the JAA and the EASA had no experts or peers to review it. The CAA had NO experts in house as they didn't permit such operations so didn't know, they did have some enlightened people but the policy was Not in my backyard still prevailed from the top down? The staff at QuinetiQ did not even bother to accept an invitation to visit a local commercial operator of SET aircraft nor attempt to discover the standards to which the 'Commercial' operators of many PC12s and TBMs operated to I gave them the names of the contacts. Ill spent JAA money for a technically thin but well padded report.
The requirement for always being within 15 minutes out of gliding distance of a suitable landing site was introduced by the CAA when I was not at the meeting. The Spanish had permitted operations from the mainland to the Balearics. The rule was not thoroughly thought through from an operational point of view as in that they state that it can only be used once per flight. They assumed that the engine always gave no warning of failure, seized instantly and that the aircraft was then at best gliding speed. They said that on airways it was illegal to convert the energy you had to altitude and thus increase the distance one could then glide. When ETOPS was introduced there was the 90 min wet footprint rule that traveled with the aircraft along the route, then increased to 180 and I think now 270 min available or more as a continuous risk period. These extensions are based on the proven in service reliability of the engines. There has not been any increase in the risk period for SET aircraft that was set some 10 years ago, yet the hours flown has increased from probably 8 million to over 20. The EROPS risk is now surely not the failure of an engine or systems but the landing at a frozen airport where the aircraft has to be evacuated because of smoke or fire and the life threatening freezing and wind chill conditions for 350+ passengers. You cannot get them to climb back up the slides and most airports don't have heated buses available to transport them to the terminal. The UK CAA introduced this face saving, not life saving proposal 15 minute proposal, but then none of 'their experts' had actually flown a civilian SET and were not aware of commercial SET operations as they were not permitted.
Some 10 years ago there were more SET aircraft operating in Europe than there were piston twins in commercial operations circa 270. These SET aircraft were not falling out of the sky due to engine failures landing on schools or orphanages, no they just got on with their job of safely transporting passengers and freight from A - B in all weathers, just we can see everyday on FR24. The vast majority were flown by private pilots not by commercially trained pilots and nor were the aircraft maintained to the proposed rigorous standards.
Yes there have been accidents and fatalities but if you analyse them in depth you will often discover that the pilot was attempting to operate the aircraft outside of the approval status shown in the limitations section of the approved Flight Manual: Often too high, too fast, not checking that they are pressurised, not de-icing the frosty wings, grossly overloaded, out of C of G. Nothing new there they do the same in twins. If an engine fails on takeoff in in a King Air or a misjudged SE Go around sadly many of us have heard the thump and seen the sickening pall of black smoke. Pilatus have proven that a well trained current pilot suffering an EFATO can if prudent turn back at a height of 750ft. I believe that the TBM has a fatal accident rate due to engine failure of ZERO.
Modern flight information data such as Skydemon and others can show you the gliding distance at any point in flight and importantly in planning the flight. Later aircraft have EFIS with Flight Planning on the IPad.
Will the sky be full of Commercially operated SET aircraft and the older twins gone to the scrap heap? Not in my opinion, the market will find its own level, there will always be the place for light piston twins, cabin class twins as well as SET aircraft. So far as over-water operations are considered a PC 12 was successfully ditched in the Pacific and so have some Caravans for they have big doors. I would not like to be scrambling to escape underwater with 9 others from some of the newer small 9 seat high wing light twins coming on the market. Islanders and Commanders don't ditch well.
Commercial customers demand reliability, goods or people transported from A to B on time on a regular basis often over great distances and if you operate old turbine twins such as Commanders, LET, MU2 and Metros or piston twins such as Aztecs, Navajos or Cessnas then unless you have spare aircraft at least 5 for every 3 needed in service then you will go bust.
Please be open minded about the development of SET operations but unless you have thoroughly evaluated both the aircraft, the equipment, the training required and the proposed regulations please don't shoot from the hip and make unsubstantiated or emotional comments.
Last edited by gordon field; 15th Feb 2017 at 18:15.
Please be open minded about the development of SET operations but unless you have thoroughly evaluated both the aircraft, the equipment, the training required and the proposed regulations please don't shoot from the hip and make unsubstantiated or emotional comments.
I think personally it all gets back to what a person is willing to accept in their perception of risk. Flew thousands of hours over water single engine (Bell 205 with T-53) in my youth knowing that a ditching in the often bad weather we had would result in our demise. Occasionally used to look at the blown spume and give Mr. Lycoming thanks for a solid product, but not something I, or the rest of the pilots, worried about. The only time we had an engine failure, and ditching, was when the engine swallowed part of the FOD screen due fatigue.
Talking to a few young PC-12 pilots engaged in a lot of night work over inhospitable country side say that engine failure is a concern. One was very happy to give up the PC-12 for a job on a King Air with two PT-6 employed in the same role.
Just one question Gordon, why was the failure rate of the PT-6 in twin installations not considered as part of the failure rate? SIL had PT-6 spit the chips, 1,000 hours on brand new airframe and engine just recently, but had another to bring him home (King Air). Think it was a stator let go.
There are additional factors to take into consideration flying IMC in SE. Richard Collins wrote much on the subject, clear air below the cloud base in the event of a failure in order to set up for the forced landing being one he cited. But once again, it's what risk you are willing to accept IMHO. Not everyone enjoys fun park rides, bungee jumping or skydiving. Motorbikes are out for me, though see the attraction.
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Megan the IFSD rate for the PT 6 included those installed in all aircraft both singles and twins and I assume fixed wing only but PW C are reluctant to publicly release data. Many of the shut downs on ME aircraft would not have happened on SET aircraft as these have redundancy built in. PWC do not state. The hr or cycles run on the engines, who overhauled them, when or type of operation.
The Working Group did consider and recognise the increased risk of flying over hostile terrain but left it to market forces to prevail otherwise some could counter that SE training in ME aircraft could be shown to have a higher but as yet unquantifiable risk.
The statistics are based on non commercial operations and hopefully the enhanced initial and recurrent training that is required should reduce fatalities. I believe that a thorough review of a selection of accidents should be part of the training for it clearly highlights what can happen if you deviate from SOP.
The Working Group did consider and recognise the increased risk of flying over hostile terrain but left it to market forces to prevail otherwise some could counter that SE training in ME aircraft could be shown to have a higher but as yet unquantifiable risk.
The statistics are based on non commercial operations and hopefully the enhanced initial and recurrent training that is required should reduce fatalities. I believe that a thorough review of a selection of accidents should be part of the training for it clearly highlights what can happen if you deviate from SOP.
Last edited by gordon field; 16th Feb 2017 at 12:19.
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The QuinetiQ report is badly flawed and was not subjected to interested party comments and peer review as the JAA and the EASA had no experts or peers to review it.
Anyway, this is all about statistics and obviously the statistics (accompanied by some lobbying work I suppose) have convinced most/all aviation authorities to allow commercial IFR operations of single engine turboprops. So be it.
However, when it comes to actually flying such a thing at night over hostile and deadly ground (like mountains and icy waters) it is no longer a statistic, but a very individual challenge for the pilot who sits at the controls. Some of us can obviously accept the situation, others can't. I only ever had one sleepless night before a flight. That was when I flew commercially on MEPs (which I still consider safer than SETs) and was facing a particularly difficult flight which was on the very limit of everything (range, payload and weather). After successfully completing that flight I promised myself that I would never again fly commercially on a piston aircraft. I still fly them and instruct on them and enjoy it a lot, but no more under the pressure of flying commercially. And I know that I am not the only one. It is an individual and emotional topic.
We are humans, not Vulcans, and therefore not able to completely suppress our emotions. Those emotions can turn the most beautiful job in the world into sleepless nights even if statistics tell my analytical mind (got myself a ph.d. in aerospace engineering in another life) that everything is going to be all right. And as I really enjoy sleeping well, I insist that my employer honors my one and unique life by putting out enough money to pay for a second engine.
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And yet, is ok to fly from Spain to Germany in a single with an engine shut down at night, but it become very scary and dangerous to fly a single turbine on the same route?
What 'redundancy' does a SE turbine have ?
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Absolutely. Which is why the statistics make such interesting reading since they show what happens in real life and not what happens in our fears and fantasies of SET and MET or MEP.
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And yet, is ok to fly from Spain to Germany in a single with an engine shut down at night,...
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What Next. Q were tasked by the by the JAA to write a report, this included The JAA seeking clarification on certain points. Q said to me that they did not have the funding necessary to enable them to visit operators, (35 Miles). They didn't try email. The Q report was included as part of an NPA and many disparaging comments were made by many using the CRD process. These comments can still be read on the EASA website and are openly critical of the findings in the report as they did not take into account as to what was actually happening in the real world and what had been happening in Europe since 1987.
The comments that I have made here and elsewhere were openly discussed at SEIMC Working Group meetings attended by the CAA and other NAAs. None of the committee members were commercial operators as such, nor manufacturers and I was the sole Industry representative as a founder member of ECOGAS (European Council of General Aviation Support). The WG had accident investigators from the BEA and Pilatus and good moderators from the JAA.
I read the comments that you and others make but am not about to enter into a general debate on the subject.
The comments that I have made here and elsewhere were openly discussed at SEIMC Working Group meetings attended by the CAA and other NAAs. None of the committee members were commercial operators as such, nor manufacturers and I was the sole Industry representative as a founder member of ECOGAS (European Council of General Aviation Support). The WG had accident investigators from the BEA and Pilatus and good moderators from the JAA.
I read the comments that you and others make but am not about to enter into a general debate on the subject.
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Gordon Field: I read the comments that you and others make but am not about to enter into a general debate on the subject.
Gordon Field has provided some really interesting background information into the early years of the Single Engine IMC Panel's deliberations, to which I - an experienced transport aeroplane pilot, both military and civil, and for some years a Principal Flight Operations Inspector - might be able to add a perspective from a regulator's (UK CAA) perspective. I was for some 20 years in the Authority's Flight Operations Department and represented such interests first in the JAA Operations Committee and then, after a three-year break, in the successor Sectorial Team. I was therefore involved initially in helping to draft JAR-OPS 1 and 3 (Flight Operations Requirements for Commercial Air Transport Operations by aeroplanes and helicopters), and latterly in revising and updated these documents. SE IMC was a topic that naturally we had to address, not least because there were Single Engine Turbine (SET) aircraft manufacturers in Europe and some aspiring SET Air Operators Certificate applicants. (Readers in the USA might remember that the term used in their documents was 'SE IFR' which of course could include flights made in VMC that the JAA saw no reason to exclude per se from SET CAT. Operating in European skies it might be difficult to ensure that VMC would obtain throughout a planned flight, but that would have to be an operational/business decision for any aspiring SET CAT operator.)
First, I call to mind that our SE IMC deliberations by the JAA Operations Committee were confined to Commercial Air Transport (CAT) operations. These have always commanded higher levels of safety for the aircraft, its occupants and the wellbeing of third parties on the ground than need to be applied to aircraft intended to be used for General Aviation (GA). By this I mean purposes such as are described in ICAO Annex 6, i.e. aircraft used for purposes other than CAT. The topic addressed in this forum, as commented upon in post 42 above, might just as well have been conducted under a CAT heading.
The design and certification of aircraft designed for CAT purposes generally incorporate higher levels of redundancy and risk mitigation than are required in aircraft used for other purposes, which is why a proposed single-engine CAT operation was always bound to deserve very careful consideration. I have no doubt whatsoever that SET aeroplanes of today together with improvements made in the past 20 years (when CAT SE IMC was first being considered in Europe) have resulted in far more reliable power plants than hitherto. Taken in conjunction with appropriate incipient failure alerting devices and frequent inspection regimes, the modern turbo-propeller engine exhibits many advantages that a piston engine cannot match.
Yet power plant reliability was only one of the issues that had to be considered. In the JAA Ops Committee we had to think of what the pilot would need to do when the engine failed - i.e. stand a reasonable chance of alighting where the aircraft would not suffer significant damage thereby allowing all on board to leave it without injury. Our concern was that the pilot needed to be able to know where he/she might aim to land and see all that would be required to manoeuvre so as to achieve this successfully. Hence the 'IMC' part of the equation. Whilst there need be no restraints on operating where the flight remained clear of cloud, mist, fog etc in daylight, the problem was how to navigate when the visibility prevented appropriate positioning to land where desired. In the mid/late 1990s the navigation systems then available could not provide suitable guidance to acceptable landing sites, and enhanced visual guidance systems didn't exist. The Ops Committee was especially concerned that flights made over the densely populated towns and cities of Europe posed a risk to those third parties on the ground I mentioned earlier in addition to the risk of injury or death to pilots and their passengers.
It was in part due to these and other issues articulated by the Ops Committee that the SET manufacturers were encouraged to find solutions that have now persuaded EASA to prescribe regulations under which SET CAT operations may take place: tough requirements introduce risk mitigations that acknowledge the absence of redundancy if/when the single engine fails, and operational constraints improve the chances that the pilot(s) may expect to be able to glide to a place where a (relatively) safe forced landing may stand every chance that the occupants will not suffer injuries and third parties, both people and property on the ground, will not be impacted.
In the early noughties I became the UK representative on the newly-constituted ICAO Operations Panel and assisted them for just under three years, where of course this topic was one of many we discussed. Our view then, as it had been in the JAA Operations Sectorial Team, was not to say 'No' to CAT SE IMC but to press for improvements in the design, certification and maintenance of SET power-plant/airframe standards together with improvements in aircraft navigation equipment and pilot training - all of which I understand have now been put in place.
SET aeroplanes have established themselves as vital to the support of life and livelihoods across the globe, mainly of course where the weather is benign and suitable landing sites can easily be acquired, and now - provided modern standards deliver the levels of reliability that are sought - we might reasonably expect the current generation of SET aircraft to become more visible in European skies.
I hope that this helps to inform readers who are interested in this topic as to why regulatory approval to operate CAT SE IMC has taken so long to merit support from the European Authorities, both before and after EASA was established.
First, I call to mind that our SE IMC deliberations by the JAA Operations Committee were confined to Commercial Air Transport (CAT) operations. These have always commanded higher levels of safety for the aircraft, its occupants and the wellbeing of third parties on the ground than need to be applied to aircraft intended to be used for General Aviation (GA). By this I mean purposes such as are described in ICAO Annex 6, i.e. aircraft used for purposes other than CAT. The topic addressed in this forum, as commented upon in post 42 above, might just as well have been conducted under a CAT heading.
The design and certification of aircraft designed for CAT purposes generally incorporate higher levels of redundancy and risk mitigation than are required in aircraft used for other purposes, which is why a proposed single-engine CAT operation was always bound to deserve very careful consideration. I have no doubt whatsoever that SET aeroplanes of today together with improvements made in the past 20 years (when CAT SE IMC was first being considered in Europe) have resulted in far more reliable power plants than hitherto. Taken in conjunction with appropriate incipient failure alerting devices and frequent inspection regimes, the modern turbo-propeller engine exhibits many advantages that a piston engine cannot match.
Yet power plant reliability was only one of the issues that had to be considered. In the JAA Ops Committee we had to think of what the pilot would need to do when the engine failed - i.e. stand a reasonable chance of alighting where the aircraft would not suffer significant damage thereby allowing all on board to leave it without injury. Our concern was that the pilot needed to be able to know where he/she might aim to land and see all that would be required to manoeuvre so as to achieve this successfully. Hence the 'IMC' part of the equation. Whilst there need be no restraints on operating where the flight remained clear of cloud, mist, fog etc in daylight, the problem was how to navigate when the visibility prevented appropriate positioning to land where desired. In the mid/late 1990s the navigation systems then available could not provide suitable guidance to acceptable landing sites, and enhanced visual guidance systems didn't exist. The Ops Committee was especially concerned that flights made over the densely populated towns and cities of Europe posed a risk to those third parties on the ground I mentioned earlier in addition to the risk of injury or death to pilots and their passengers.
It was in part due to these and other issues articulated by the Ops Committee that the SET manufacturers were encouraged to find solutions that have now persuaded EASA to prescribe regulations under which SET CAT operations may take place: tough requirements introduce risk mitigations that acknowledge the absence of redundancy if/when the single engine fails, and operational constraints improve the chances that the pilot(s) may expect to be able to glide to a place where a (relatively) safe forced landing may stand every chance that the occupants will not suffer injuries and third parties, both people and property on the ground, will not be impacted.
In the early noughties I became the UK representative on the newly-constituted ICAO Operations Panel and assisted them for just under three years, where of course this topic was one of many we discussed. Our view then, as it had been in the JAA Operations Sectorial Team, was not to say 'No' to CAT SE IMC but to press for improvements in the design, certification and maintenance of SET power-plant/airframe standards together with improvements in aircraft navigation equipment and pilot training - all of which I understand have now been put in place.
SET aeroplanes have established themselves as vital to the support of life and livelihoods across the globe, mainly of course where the weather is benign and suitable landing sites can easily be acquired, and now - provided modern standards deliver the levels of reliability that are sought - we might reasonably expect the current generation of SET aircraft to become more visible in European skies.
I hope that this helps to inform readers who are interested in this topic as to why regulatory approval to operate CAT SE IMC has taken so long to merit support from the European Authorities, both before and after EASA was established.
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Thank you Nugget for a very balanced and informative post.
I did find that many within the NAAs and JAA/EASA did not take into account the considerable number of privately operated SET aircraft that were actually safely operating within 'EASA airspace' on a regular day to day basis. This includes a considerable number of Piper Jet prop aircraft that have been modified by replacing the piston engine with a PT6.
There were and still are some very good operators who operate to the proposed regulations but also many privately owned aircraft aircraft where once the pilot had been issued with his 'Type Rating' (not required for the C208) then they were left to really set their own standards for recurrent training.
Yes there have been some accidents to SET aircraft in Europe but in general these have not been caused by the loss of thrust but more likely by flying the aircraft outside of its permitted limits.
The changes in the way that the winds aloft, glide distance, traffic/terrain mapping, and weather data and programmed landing sites is now available to the pilot will further increase safety.
The requirement that the pilot can (should) only use the 15 minute risk period once per flight is clearly nonsense and is not in accordance with the ICAO SARP as the potential for loss of thrust in the cruise sector is significantly less than during the climb out.
I just hope that there are still a sufficient number of experienced Operations Inspectors employed by the NAA to deal with the applications in a timely manner.
I did find that many within the NAAs and JAA/EASA did not take into account the considerable number of privately operated SET aircraft that were actually safely operating within 'EASA airspace' on a regular day to day basis. This includes a considerable number of Piper Jet prop aircraft that have been modified by replacing the piston engine with a PT6.
There were and still are some very good operators who operate to the proposed regulations but also many privately owned aircraft aircraft where once the pilot had been issued with his 'Type Rating' (not required for the C208) then they were left to really set their own standards for recurrent training.
Yes there have been some accidents to SET aircraft in Europe but in general these have not been caused by the loss of thrust but more likely by flying the aircraft outside of its permitted limits.
The changes in the way that the winds aloft, glide distance, traffic/terrain mapping, and weather data and programmed landing sites is now available to the pilot will further increase safety.
The requirement that the pilot can (should) only use the 15 minute risk period once per flight is clearly nonsense and is not in accordance with the ICAO SARP as the potential for loss of thrust in the cruise sector is significantly less than during the climb out.
I just hope that there are still a sufficient number of experienced Operations Inspectors employed by the NAA to deal with the applications in a timely manner.
Join Date: Feb 2009
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Hello all,
Anyone could help with finding any research on PROS & CONS, accident rates, etc on Single Engine Turbo Prop vs Multi-Engine Turbo Props?
Thanks in advance.
LCL
Anyone could help with finding any research on PROS & CONS, accident rates, etc on Single Engine Turbo Prop vs Multi-Engine Turbo Props?
Thanks in advance.
LCL
Join Date: Jan 2001
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Reliability on many piston engines is largely affected by maintenance and pilots. Turbines are seeing professional handling and pilots in most cases. The engines are not guilty if the owner doesn't care and the pilot doesn't either.
They had to shut that side down
Single Turboprop over heavy seas at night ?
You at least owe it to the PAX to well inform the PAX of those risks