RobertL18C wrote:
I think the poster child is the safety record between the King Air and the PC-12. Here we have similar missions, with professional crew (in some cases crews), and the PC-12 enjoys a better safety record. The advantage is possibly marginal, but combined with the economics this led to the marketing segmenting between the PC-12 and the KA350, and sales of the 90/200/250 reducing.
That sounds more like a like-for-like comparison. The economics certainly also helped to displace the lower-end King Airs, including the insanity of EASA (now gone) “complex” designation for multi-engine turboprops. In addition, the TBM as the go-fast plane made the C90 look rather unattractive for those who don’t need a big cabin.
The twin specific accident is loss of control after engine failure.
The single specific accident is a failed emergency landing after engine failure.
Stats are hard to come by, but the killer analysis would be what percentage of engine failures in the King Air lead to a LOC, compared to what percentage of engine failures in the PC12 lead to a failed emergency landing (failure being serious injury or death).
There may be a risk assessment study somewhere which underpinned the switch to the PC-12 by the RCMP and the Australian Outback Doctor Service?
Where the KA engine reliability is reduced is in problems with the FCU or auto feather causing crew confusion.
Cobalt wrote:
The twin specific accident is loss of control after engine failure.
The most relevant twin specific accident is loss of control after simulated engine failures. There is some truth in the words: “Twin flying is really safe – if you survive the training!”
Cobalt wrote:
That sounds more like a like-for-like comparison. The economics certainly also helped to displace the lower-end King Airs, including the insanity of EASA (now gone) “complex” designation for multi-engine turboprops.
To be precise, they are still classified as complex, which e.g. affects maintenance, but they can be operated under the non-complex ops rules (part-NCO).
I nearly responded “maybe, but unlikely in a King Air” when I remembered a particularly famous accident where a Cheyenne (also a twin turboprop) crashed into a McDonald’s in Munich when the examiner pulled power at 200ft AGL (and well below the power required to simulate a failed engine) and the pilot lost control. So there certainly is that factor even at the higher end.
However, when comparing PC12 and King Air the training accidents will easily be eliminated from the statistics. What will be a bit harder is to get the number of engine failures in the twin, as reports will be incomplete – not quite as easy as counting up the accidents and forced landings, which will be in the (public) accident investigation data.
So unless someone has done extensive research including getting MOR data on in-fight failures (and analysing which of them were actual failures), the single vs twin debate will remain unresolved – and that is a good thing, we will run out of Covid at some point and need other things to discuss…
Airborne_Again wrote:
To be precise, they are still classified as complex, which e.g. affects maintenance, but they can be operated under the non-complex ops rules (part-NCO).
Thank you, I didn’t realise that!
What is the practical difference in maintenance in that class?
Cobalt wrote:
What is the practical difference in maintenance in that class?
One thing is that you can’t use part-ML even if the aircraft MTOW is 2730 kg or less.
The PC-12 has an SET class rating requiring revalidation every two years, while the multi is an annual class rating revalidation cycle. With $5 to 8MM hulls the crew are likely to be trained every six months in any event.
While the accident or fatality rate per 100,000 hours is a blunt instrument, it is the accepted convention. Commercial Air Transport seeking a rate below 1 in a million hours, and CAT121 may be around 1 in 50 million, although the CAT121 record is so good it arguably is in a different category to international airlines (non US). The DA40/172/PA28 class typically are well below the 1/100,000 ratio, no doubt because they are in a training environment. The actual hours flown by Part 91 equivalent, private, non training, non aerial work, MEP must be so low that calculating a fair statistic may be impossible. The industry that forms a view on this, is the insurance industry, and at least in the USA getting decent insurance cover on an MEP is becoming harder every year.
RobertL18C wrote:
the CAT121 record is so good it arguably is in a different category to international airlines (non US).
Really, compared to major western international airlines as British Airways, Lufthansa, Quantas or (shudder) Ryanair?
@Airborne_Again very fair point. Interestingly there isn’t a table showing individual airlines but I found this study by Airbus which shows how the industry continues to improve safety.
