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Next step - turboprop vs twin

Rami1988 wrote:

your single piston still has a 1 in 3250 hours chance of breaking at any moment.

During the 11 years I’ve been in my club in my borne again flying life, the club has produced some 13,000 hours. In that time we’ve had exactly one case of an engine “breaking” in flight. The likelihood of not more than one engine failure would be less than 1 on 10. On the other hand, with a MTBF of 50,000 hours, the likelihood of at least one engine failure in 13,000 hours is about 1 in 4….

So I believe the 50,000 hour figure more than the 3,250 one…

Last Edited by Airborne_Again at 15 Jun 20:02
ESKC (Uppsala/Sundbro), Sweden

I could keep my TB20 for sightseeing, and a TP to go places.

It’s hard enough to stay proficient in one plane, especially for an inexperienced pilot fresh in owning a SET. Dividing your annual hours among two planes will not help.

Personally I’d recommend to keep the TB20 for 500 hours and adjust your flights to match your risk comfort zone. Then look on…
There are a lot of things a TB20 can do that a fast touring SET can’t.

EASA BIR CFI
LO__, Austria

My view also. And I have flown in the Jetprop, TBM, CJ4…

As I said, the Jetprop is a good general purpose plane with loads of performance. You can use it as a hack, chuck some bikes into the back, etc. But forget

  • taking photos looking down
  • grass (unless you know exactly what you are doing)

But as I wrote before, need to be a good technical pilot, with good understanding of wx, aircraft systems, flight dynamics, etc. And your “maintenance landscape” will likely be much more challenging. Owners of TPs tend to be flying to specific dealers and then having to make their way back home, then same in reverse a bit later. That would drive me crazy.

BTW my link above sold a good number of TBMs but Socata never paid me any commission

Administrator
Shoreham EGKA, United Kingdom

Rami1988 wrote:

How many flying hours did you have at the time?

At the time, 500 hours plus IR and HPA were requirements for the class rating and I had exactly that. The 500 hour requirement has since been removed. They may ask to fly with a mentor pilot for some time. I went solo with a freshly printed licence. Not that I recommend it, but it’s possible.

Last Edited by loco at 15 Jun 20:41
LPFR, Poland

Peter wrote:

Source for that number please?

The real number is probably higher due to underreporting.

For example this:

https://www.atsb.gov.au/sites/default/files/media/29980/b20070191.pdf

The UK AAIB, in the course of its investigation of the Cessna 404 Titan G-ILGW
accident (UK AAIB report 2/2001), raised the issue of engine reliability with
several regulatory agencies and asked for data on in-flight shut-downs by different
models of reciprocating engines. The response from the FAA, and other agencies,
was that no reliable data exist for this kind of comparison, largely due to ‘gross
under-reporting’ of in-flight shutdown of general aviation piston engines. The FAA
assessed the rate as ‘between 1 per 1,000 and 1 per 10,000 flight hours. This failure
rate, qualitatively described as ‘probable’ or ‘reasonably probable’, is well in excess
of the ‘improbable’ or ‘extremely remote’ reliability goals expressed in design
standards.

EGKA, United Kingdom

loco wrote:

At the time, 500 hours plus IR and HPA were requirements for the class rating and I had exactly that. The 500 hour requirement has since been removed. They may ask to fly with a mentor pilot for some time. I went solo with a freshly printed licence. Not that I recommend it, but it’s possible.

I only have around 200 now.. as Peter/Snoopy suggesting i should probably build some more hours first..

EGKA, United Kingdom

On twins it would be under-reported but an engine stoppage in singles is very unlikely to be so.

And engine stoppages on twins are often said as a lot more likely to happen due to various factors e.g. more vibration, longer control cable runs, etc.

Many other threads on this before but a much bigger reason for engine stoppages is too much air in the fuel tanks Another reason is mismanagement of fuel servo icing and this was probably another.

Administrator
Shoreham EGKA, United Kingdom

Yes – i think about 50-60% are fuel related (contamination or starvation) and other things you can control.

You can also argue that these stats include crappy engines that are not well looked after

But still they are not reliable enough. I would say 1 in 100,000 is where that starts to become ‘extremely remote’ as the ATSB calls it.

EGKA, United Kingdom

Peter wrote:

On twins it would be under-reported but an engine stoppage in singles is very unlikely to be so.

Interesting read – in the US, there is no requirement to report an engine failure where no serious injury (or one of a list of things..) occurs

https://www.ecfr.gov/current/title-49/subtitle-B/chapter-VIII/part-830

A flight control issue, however, is reportable.

Strange….

EGKA, United Kingdom

@Peter landing a twin with a Vs of 80knts is no different to landing a single with a Vs of 80kts. Even with both engines out. The difference is a matter of inertia due to weight.

For the mathematicians. Lycoming publicity material claim an engine failure rate of 1:1000. What that converts to in the failure of one engine over how many hours is for the rocket scientists amongst you.

France
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