Engine failure in WWII
 

Hello. I don't know if this is the right place to ask these things. If not, I apologize in advance. I'd like to know if, during the WWII, a twin engine aircraft could fly without an engine.

1) Is it correct that a twin engined aircraft, in normal contitions, has exactly twice the power needed to fly?

2) Could an aircraft like a Vickers Wellington take off and/or fly with one engine out of service?

Thanks in advance.

1. The power needed depends on the aircrat weight. A heavily loaded aircraft might just have enough power to maintain height on one engine, but it's not as simple as having twice the power.
2. If it tried to take off, the assymetric power would turn the aircraft and it would leave the runway before there was enough speed to enable the rudder to keep the aircraft straight. Every twin- or multi-engine aircraft has a "safety speed" below which it is not possible to maintain controlled flight. In the case of the Mosquito an engine failure immediately after takeoff - before reaching that speed - could be fatal.

Engine failure in WWII

Nothing to do with WWII. Aeroplanes will not take with only one engine on one side NOW.

Aero Commander famously demonstrated the 500's single engined performance by flying the prototype from Bethany to Washington on one engine - with the prop stowed in the cabin!

With some Twin engined aircraft - the old saying went something like....

The remaining (live) engine would take you to the scene of the ensuing crash.

1) No. A twin has enough power on one engine to fly a specified minimum climb rate at MTOW, but several older types may not be able to achieve this.
2) Most likely not. Taking off with such a massive power imbalance would be near impossible, as mentioned above. Flying with one engine out might be possible provided the loading would allow this and the aircraft has enough speed.

Did a spot of ME training on the Vickers Varsity which was powered by 2 Bristol Siddley Hercules 264 engines - it was a derivative of the Wellington and the Viking.

Rotation speed was around 85kts and 2 eng safety speed was 105kts. Thus, if an engine failed between 85 and 105kts, you were going to crash. Directional control between those speeds could only be maintained by reducing boost on the live engine.
Happy days!
mcdhu

A twin can get airborne on one engine, but it would require a very long runway. To begin with, very little power against maximum rudder. As the rudder becomes effective, more power can be added to balance it. However, before a sensible rotation, both VMCG and VMCA should be achieved. For the uninitiated, minimum control speed on the ground; minimum control speed in the air. Not a very sensible idea, and should only be used if the Martians are coming over the hill.

1) I do recall that the D18S (Beech 18) for exemple had a "Wartime Takeoff Weight" Written on its flying manual.
Noooo f.. way it could stay airborne on one at this published weight! It would barely take Off actually...
2) You are talking about WWII era type of aircraft so no.

Past inertia, twin engines with tail wheel cannot even taxi on one engine.

Must have amassed considerable time in that period between lift-off and safety speed in the Anson, Valetta, Marathon, Hastings before arriving at the RAF's first Perf A aircraft - the mighty Bev! Then back to the 'waiting' in aaaaaahhh DH's Devon. It was one of those things best characterised by the FAA's reported utterance after a successful catapult launch - "Thank you God, I have control now!"

I had a boss who had been a Navigator on Mosquito's - he reckoned if anything went wrong it was a damn dangerous aircraft - hard to get out of for a start - and as you say - takeoff had no margin for error

The Mosquito makes the Canberra appear positively benign in the EFATO case, but sadly many found it not to be so

An evaluation of the BN2 Defender (military version BN2A Islander) in Abu Dhabi in the early 1970's drew the conclusion that the aircraft should be operated as though it was a single-engine aircraft and carry out a semi-controlled forced landing immediately if one engine failed.

IIRC the principal reason was that with a fullish load and summer air temperatures, the remaining engine could only be run at max continuous power for about 5 minutes before overheating, and that at any lower setting could not maintain level flight. In this regard it resembled quite a few older-generation military twins, some of which simply could barely maintain level flight on one engine at max weight at any power setting, let alone climb.

" that the aircraft should be operated as though it was a single-engine aircraft and carry out a semi-controlled forced landing immediately if one engine failed."

That's standard advice for a whole slew of US light twins built from the '50's onward - whatever the book says in most cases one engine just gives you a wider choice of where to put down. :ouch:

Yes; I did my twin-rating training and test on a Piper Aztec A; level flight on one engine was just possible with the instructor, me, and fuel for an hour or two. But with a normal load and fuel it was a case of quickly finding a good place to land before hitting the ground.

PS....I forgot to mention that neither in the training or the test did we attempt a simulated EFATO; the instructor described it as suicidal. "Pretend you're in a single and land ahead. Don't even think about trying a turnback, you'll crash and burn if you do."

I remember seeing pix of a Grumman Goose taking off on one engine, so of the era. Huge curved run, but they had cheated and fitted two turbo props with a bit more power.
Also, our commercial pilot giving me some engine out experience in a Piper Apache, so like an Aztec, but rather less power. This was at about 1500 ft in rain.:ooh:
Doubt we would have got far if one had failed for real.

My father was a Rad/Nav in Night Fighters, serving 3 Tours.

Losing an engine in a fully laden Mossie at take off = crash, as they found out!

On the roll, the port engine lost all it's glycol and his pilot attempted a low circle to get back to the field but there was not enough time. Here is the direct quote from my father's log book:

The three men were given the British Empire Medal. My father and his pilot continued operations until the end of the war. His pilot stayed on and became an Air Commodore. My father left the service in '46. They remained friends for life.

Boris Johnson's grandad had an engine failure in a Wimpey shortly after departing Chivenor on an op during WW2 with a full load of bombs and depth charges. He immediatley elected to return to base but unfortunately after the dead engine caught fire and detached itself from the aircraft, he crash landed and sustained an injury which cut short his flying career.