Single Engine Performance

[rkk01]

I know that the Mosquito had a reputation as a dangerous aircraft in the event of an engine failure, especially in low / slow flight 

Has anyone else found that “making it back on one” vs crashing seems inconsistent?

Sometimes I can feather the dead engine’s prop and keep the airspeed up enough to maintain control… and get home for a decent landing

Other times the loss of an engine requires a constant loss of altitude to keep the airspeed up… until there’s none left

(I suppose the old adage of the remaining engine just carries the aircraft further to the eventual crash site…)

Aircraft weight perhaps? Get rid of any excess as soon as that prop is feathered???

[razo+r]

I am not sure if you cannot fly on one engine at full weight, but if you are on one engine only, it's always a good idea to take measures that maximise the performance. Dropping weight, reducing drag, if necessary go lower and mantain coordinated flight. 

Can you reproduce your inability to fly in a short track? Like set up your aircraft with the same loadout in the air and turn off one engine. 

[Skewgear]

Minimum single engine speed is around 150mph. If you are slower than that, you will crash. Lose height to regain speed.

There is no going around from a poor approach if your speed is below 150mph. Accept you are going to land on the ground in front of you once your airspeed is below that critical point.

Do not lower the gear until you are committed to landing, and remember it takes longer to extend and lock because you'll only have one hydraulic pump.

Maximum power on the remaining single engine is 12lbs. More than that and you will exceed the combined rudder and trim authority needed to overcome the asymmetric thrust, meaning you will crash.

The Mosquito cannot maintain height on one engine with the dead engine's prop unfeathered. If you cannot feather it, you will stall and crash.

Dump all extra weight (bombs and drop tanks) as soon as you can after shutting down and feathering a dying or dead engine. Remember to shut the bomb doors and the radiator flap for the dead engine.

Don't be afraid to make an early decision to put it down in a field. Better to survive the inevitable crash than not.

[Nealius]

3 hours ago, Skewgear said:

Don't be afraid to make an early decision to put it down in a field. Better to survive the inevitable crash than not.

This has been my motto for all the warbirds when dealing with engine troubles. 

[Bozon]

21 hours ago, rkk01 said:

I know that the Mosquito had a reputation as a dangerous aircraft in the event of an engine failure, especially in low / slow flight 

For a twin engine plane the Mosquito was actually considered as easy to fly on one engine. When not heavily loaded it had enough excess power to climb and do aerobatics as in the famous demonstration flight by de Havilland.

As you mentioned the difficulties were with the landing and takeoff. @Skewgear post has all the important operational tips. My thumb rules:

1. Feather the dead engine, or look for a place to crash land. You cannot maintain flight with a prop acting as a speed brake.

2. Keep the speed above 170 mph - you can go a little slower, but it gets very tricky, so don’t. At 170+ you can open up with the good engine without losing control.

3. If you dropped to 150 mph you will not recover - reduce power and go for deadstick crash landing.

4. All the above mean that if you made it to a runway, come at 170 mph with a little excess altitude, lose altitude to keep 170 while the undercarriage lowers, and on final commit to a power-off landing. Extend flaps as airbrakes to steepen your glide angle while maintaining airspeed - It is best to come glider-style, i.e., fast & steep with a lot of drag extended so you can aim well at the flare point, and don’t float all the way past the runway.

[rkk01]

I’ve successfully flown and landed the Mossie on one engine many times… it just seemed random that sometimes this worked “per the book” and other times it was a non-starter.

Looking back I think it must have been missions with high fuel / weapons loads

Edited December 7, 2023 by rkk01

[grafspee]

It also depends which engine you lose, if it is left engine airplane is harder to control at low speed then if you would lose right one.

[rkk01]

5 hours ago, grafspee said:

It also depends which engine you lose, if it is left engine airplane is harder to control at low speed then if you would lose right one.

Yes, that also fits with my experience