Menu Sign In Contact FAQ
Banner
Welcome to our forums

...to the scene of the crash (The second engine in a twin takes you to...)

What a wonderful piece of journalistic playing with statistics :-D

EGKB Biggin Hill

A thoughtful and updated article by Richard Collins which paints twins in a better light (Dick Collins in fact started the debate debunking the safety advantage of twins), although the Cessna 172 0.56/100,000 hours remains hard to beat.

https://airfactsjournal.com/2015/09/crashes-now/

Enstone (EGTN), Oxford (EGTK)

What a wonderful way of dismissing a factual argument that goes against your view ;-)

This stat shows that not only twins are less safe than singles, the second engine is a net safety cost on top of the fact that it doubles your probability of having an engine failure.

Last Edited by denopa at 30 Dec 21:06
EGTF, LFTF

denopa wrote:

This stat shows that not only twins are less safe than singles.

True

[it shows that] the second engine is a net safety cost

This cannot be concluded from the statistics in the article – correlation does not prove causation.

There are only two significant twin-specific accidents: loss of control in asymmetric flight, and continuing to a CFIT when a single might have made a successful forced landing. You would have to count these, and compare them to their single engine equivalents (stall/spin after engine failure, and forced landing accident) to come to any meaningful conclusion.

on top of the fact that it doubles your probability of having an engine failure

Almost certainly wrong. A significant proportion of engine failures are due to fuel starvation. That makes it significantly less than half.

Don’t get me wrong – there are certainly several reasons why twins can pose higher risks than singles. They tend to be more complex, faster, and heavier than singles, which makes them more demanding on the pilot, and increases the severity of accidents if they happen. So they need more currency and training to remain safe.

There are also unrelated reasons why twins have higher accident rates, driven by their typical mission profile.

Last Edited by Cobalt at 30 Dec 22:12
Biggin Hill

Dave_Phillips wrote:

No. 2 – PA31-350 engine failure after take-off. OAT 48 deg Celcius, aircraft 200lbs short of 7000lbs

Man – that is a good example of Murphys law…

Well done..

You drill the routine with instructors so many times, it should be a non event.

It is difficult to understand the point of view that twins are less safe than singles.

Here is a video of someone showing how not to do it..


liftvectorup wrote:

You drill the routine with instructors so many times, it should be a non event.

Depends when it happens. Non-event is a bit of a stretch. With instructors you also know it is coming.

liftvectorup wrote:

It is difficult to understand the point of view that twins are less safe than singles.

Personally I think they are overall safer but the sort of accidents they do have tend to be more fatal.

EGTK Oxford

denopa wrote:

What a wonderful way of dismissing a factual argument that goes against your view

Not a bit of it. Try expressing the view you wrote mathematically and you will find that there is zero logic in it.

https://www.datapine.com/blog/misleading-statistics-and-data/

EGKB Biggin Hill

That’s Glenn Hancock in the 680FP that lost the engine in initial clip. He’s president of the Twin Commander Flight Group. He’s had a lot of troubles with his old 680FP. He bought it from Moe Mills (a legendary owner in the TC world) when he died. Unfortunately, Moe hadn’t flown or maintained the aircraft well over the least few years of his life, so Glenn’s been very patient with it. It’s got the supercharged 380hp geared engines and they’re expensive to maintain and has a lot of old systems, like hydraulic pressurization etc. This plane is truly the case where a Turbine Commander would have been cheaper to both maintain and fly. He’s finally got it flying pretty reliable now, but it’s taken him two years of constant tinkering.

Statistics for twins are nowhere to be found, because all the times a twin returns to land safely doesn’t get reported. So no assessment of their safety can be made statistically.

Sign in to add your message

Back to Top