Menu Sign In Contact FAQ
Banner
Welcome to our forums

Crash LPCS (also engine failure probability on a twin)

EFATO in a prop twin is probably about the most dangerous situation that is somewhat frequently encountered.

I don’t have any stats, but just a WAG that it accounts for a significant portion of fatal accidents for twin prop planes.

The main problem is the asymmetrical drag/ power situation before the prop can be feathered .

That said, most TPs have auto-feather, not sure for the Cheyenne II ?

FAA A&P/IA
LFPN

Did not flew the Cheyenne but the Conquest I have auto feather…

LFPT Pontoise, LFPB

Michael wrote:

The main problem is the asymmetrical drag/ power situation before the prop can be feathered .

This is interesting. I’ve heard it said many times that twins are more dangerous than singles because you have twice the chance of an engine failure (and dealing with one is hard, especially EFATO).

I don’t think this is true of modern twins though, I was incredible impressed by the speed of the auto-feather on the Diamonds.

EGTR

Peter wrote:

The light aircraft, which was carrying four people, is said to have exploded in mid-air and come down near a Lidl supermarket in Tires, landing on a lorry that was unloading.

What could cause that? That’s really unusual in light GA.

Agreed, but it has happened on type before – here

Last Edited by 172driver at 19 Apr 15:56

Actually it’s slightly more than twice, as you may have a double engine failure in a twin.

Don’t you need to switch the engine master off on the DA42 to feather?

The auto feather on a turbine may not operate correctly, for example, if you have a faulty fuel control unit which results in a partial power failure.

Oxford (EGTK)

172driver wrote:

Agreed, but it has happened on type before:

The Navajo and the Cheyenne are about as similar as the Dalai Lama and Donald Trump.

Fly safely
Various UK. Operate throughout Europe and Middle East, United Kingdom

@Dave_Phillips, you are, of course, correct.

nokicky wrote:

I don’t think this is true of modern twins though, I was incredible impressed by the speed of the auto-feather on the Diamonds.

There is no such thing as auto-feather on DA42 and DA62 (Diamonds), and Diamond does not make any TP twins.

You therefore need to identify, confirm and feather (turn off engine master) which does take a little bit of time. If EFATO you may be better off throttling back and land straight ahead. After having feathered, the A/C may climb at 200 fpm on a good day provided you nail Vyse and bank slightly into the good engine. Otherwise it will not climb at all.

Last Edited by Aviathor at 19 Apr 18:22
LFPT, LFPN

Aviathor wrote:

There is no such thing as auto-feather on DA42 and DA62 (Diamonds), and Diamond does not make any TP twins.

I googled a little and found that autofeather only became available as an option on the Cheyenne III. The aircraft that crashed in Cascais was a Cheyenne II, so I don’t think it had an autofeather system. Personally I have no experience with that aircraft and therefore could have been mislead by the internet in that respect.

EDDS - Stuttgart

Aviathor wrote:

There is no such thing as auto-feather on DA42 and DA62 (Diamonds), and Diamond does not make any TP twins.

You therefore need to identify, confirm and feather (turn off engine master) which does take a little bit of time. If EFATO you may be better off throttling back and land straight ahead. After having feathered, the A/C may climb at 200 fpm on a good day provided you nail Vyse and bank slightly into the good engine. Otherwise it will not climb at all.

It’s not that bad. I’ve had 450ft/min out of a DA42 at Vyse (I’ve also battled to achieve 50-80ft/min but the OAT was in the mid-40s). In the DA62 blue line feels uncomfortably slow; we add 5-10KIAS to that number and achieve about 150-200ft/min.

Fly safely
Various UK. Operate throughout Europe and Middle East, United Kingdom
Sign in to add your message

Back to Top