A.P. 129 RAF Flying Training Manual, Part I - Landplanes

[Seadog]

Originally Posted by Crumpp

No I think they tore up a lot of engines. In fact, I think it was to the point the Operations and Maintenance Chiefs expressed enough concern for Dowding to do something about it.

Dowding states that the the EBCO allows for 12lb boost for 5mins. I know you love the RR Merlin but would you really have us believe that this could be done with 87 octane fuel?

[Crumpp]

A override for take-off is linked to extra rich mixture to preventing detonation.

Exactly. It was used to test the engine at altitude during service maintenance.

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!

If they tested the engine to 10.5lbs then a low engineering safety factor of 1.6 yields 16.8lbs. That pilot who did that was extremely lucky his engine did not destroy itself from detonation.

AIR MINISTRY
Air Publication 129
Revised November 1937
Royal Air Force
FLYING TRAINING MANUAL
Part I - LANDPLANES
Chap. II
Aero-engine speeds and boost pressures
66. (vi).(c). Aircraft should not be flow at the maximum conditions for level flight except in emergency, or when special operational conditions necessitate it.

[fruitbat]

Originally Posted by Crumpp

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!

Where? Source please.

[Seadog]

Originally Posted by Crumpp

Exactly. It was used to test the engine at altitude during service maintenance.

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!

If they tested the engine to 10.5lbs then a low engineering safety factor of 1.6 yields 16.8lbs. That pilot who did that was extremely lucky his engine did not destroy itself from detonation.

Weeeeeeeeeeeeee boooom...!

That's the sound of Crump's credibility cratering...

16lb boost with 87 octane...

Crump an RAF fanboy...who knew?

[41Sqn_Banks]

Originally Posted by Crumpp

Exactly. It was used to test the engine at altitude during service maintenance.

As said: There is no "override" for Merlin II/III engines. There is no device for extra rich mixture for take-off. There is only a cut-out to disable the boost control. But this was not used for take-off, as maximum take-off boost is the regular rated boost of +6.25.

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!

Great, show us the anecdote.

If they tested the engine to 10.5lbs then a low engineering safety factor of 1.6 yields 16.8lbs.

Once again you forgot atmospheric pressure in your calculation.
10.5lbs (+ 15.0) is 100%
16.0lbs (+ 15.0) is 121,56%
This is only a factor of 1.2; a factor of 1.6 would be +25.8lbs (+ 15.0).

Exactly. Only in emergency or special operational conditions the aircraft is flow at the "maximum rpm/boost for level flight" (later called "all out") limits and not above.

[Crumpp]

There is no device for extra rich mixture for take-off.

Read the description in AP129.

[Crumpp]

Once again you forgot atmospheric pressure in your calculation.

OOPS. Of course the British have to be different. Not any better, just different from everyone else in the world.

MAP - Manifold Absolute Pressure and it does not mean Manifold AIR pressure.

Good, I was thinking 1.6 is pushing it for the odds of somebody attempting it and surviving.

1.2 makes his story more credible, still very lucky but definately more credible that he was able to push it to +16lbs momentarily on 87 Octane.

[Seadog]

Originally Posted by Crumpp

OOPS. Of course the British have to be different. Not any better, just different from everyone else in the world.

MAP - Manifold Absolute Pressure and it does not mean Manifold AIR pressure.

Good, I was thinking 1.6 is pushing it for the odds of somebody attempting it and surviving.

1.2 makes his story more credible, still very lucky but definately more credible that he was able to push it to +16lbs momentarily on 87 Octane.

"credible" ....

[fruitbat]

Still no source, i wonder why.......

[Glider]

At least no one has said 16 squadrons

Damn