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

[41Sqn_Banks]

Originally Posted by Crumpp

It specifically says in engine limitations, Paragraph 3(ii):

"These figure provide a general guideline to the reasonable use of the engine. In combat and emergency other considerations may justify the pilot in disregarding these limitations[SIC!]"

You cannot look at a combat report that used an overboost condition as proof of 100 Octane fuel use.

Let's look at the full Paragraph 3:



"these restrictions" in the context of the paragraph related to the "Duration and Flight Condition" restriction of the engine limitations. For example a pilot may use combat power for longer than 5 minutes or use combat power to climb to operational height in combat or emergency.
I'm afraid this quote does not support your theory.

[NZtyphoon]

Originally Posted by Seadog

I have to admit that I'm surprised that Crump expresses such faith in RAF and UK technological superiority, especially his belief that the RR Merlin could run at 12lb boost for 5 minutes with 87 octane fuel... As much as Crump might wish for this to be modelled in CloD, I should like to agree with NZtyphoon that the Merlin III required 100 octane fuel when pulling greater than 7lb boost.

However, if one reads the memo carefully, Dowding is referring to running the engine beyond it's oil and coolant limits during climbs and to oil starvation during inverted flight, and running the engine beyond 5 minutes as the major culprits in causing engine damage.

Too right, nor did Dowding waste his time by writing to all frontline fighter pilots telling them to refrain from using boost override or exceeding boost limits for 87 octane fuel - why? - because he knew they were all using 100 Octane and was warning them against overuse of +12 lbs boost, as well as the other limits described by Seadog.

[Crumpp]

"In combat and emergency other considerations may justify the pilot in disregarding these limitations"

The Air Ministry gave license to violate the airworthiness of the aircraft. It is no wonder Dowding was concerned.

And yes, any pilot reading that would understand they do what they must to survive even if it means "disregarding these limitations" published in the Operating Notes.

There is no doubt that RAF pilots used whatever system was available to increase the limitations irregardless of fuel type.

[Crumpp]

Crump expresses such faith in RAF and UK technological superiority

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.

[NZtyphoon]

Originally Posted by Crumpp

"In combat and emergency other considerations may justify the pilot in disregarding these limitations"

The Air Ministry gave license to violate the airworthiness of the aircraft. It is no wonder Dowding was concerned.

And yes, any pilot reading that would understand they do what they must to survive even if it means "disregarding these limitations" published in the Operating Notes.

There is no doubt that RAF pilots used whatever system was available to increase the limitations irregardless of fuel type.

Absolute nonsense - once again for your benefit Crumpp, because you clearly have trouble reading beyond your preconceptions - Dowding specifically mentions +12 lbs boost and nothing else.

All of your suppositions about what the pilots will do is just that - pure conjecture without a single shred of evidence from you showing that pilots were so used to using 87 octane that in the heat of combat they pulled emergency boost expecting to do what exactly? Boost override was not available with 87 Octane fuel - period.

You have led the same song and dance routine over this "issue' over several threads now, and it is clear you are totally obsessed with your own interpretation of things, regardless of whatever evidence is placed in front of you. Go away and waste time elsewhere - this thread was not intended to be yet another argument over what Crumpp believes about 100 octane fuel.

[41Sqn_Banks]

Originally Posted by Crumpp

The Air Ministry gave license to violate the airworthiness of the aircraft.

... in March 1943.

It is no wonder Dowding was concerned.

... in August 1940.

There is no relation between the two. Also:
"A recent increase in the number of engine failures, due to failure of bearings, is an indication that some pilots are overstepping the engine limitations laid down in the Pilot's Handbook."
Doesn't sound like exceeding the limitations was a tolerated behavior in 1940.

[Crumpp]

Boost override was not available with 87 Octane fuel - period.

Nonsense, boost override was and was even tested at service inspection. It was not authorized for use except at take off.

However the Air Ministry clearly states:

"In combat and emergency other considerations may justify the pilot in disregarding these limitations"

You just don't like that fact.

I was the one who told you that Operating Notes are mandatory to follow, linked to the airworthiness of the design, and done by convention.

They are very specific in what can and cannot be done. To include the specific passage the Air Ministry thought to include:

"In combat and emergency other considerations may justify the pilot in disregarding these limitations"

[41Sqn_Banks]

Originally Posted by Crumpp

Nonsense, boost override was and was even tested at service inspection. It was not authorized for use except at take off.

The Merlin II/III doesn't have a override for take-off, it only has a cut-out for emergency. A override for take-off is linked to extra rich mixture to preventing detonation. The cut-out does not increase mixture, thus requires higher octane fuel to prevent detonation.

"In combat and emergency other considerations may justify the pilot in disregarding these limitations"

- quoted wrong (it says "restrictions" and not "limitations")
- quoted out of context (the context are time and flight condition limits, not boost limitations)
- quoted comes from a later source (March 1943, thus not related to 1940)

The RAF fanboys would love to see a proof that 87 octane was not required for +12 boost with Merlin engines. No one cares about the type of fuel, it's the +12 boost everyone is interested in.

[fruitbat]

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.

Speculation, not fact.

[GraveyardJimmy]

Originally Posted by Crumpp

However the Air Ministry clearly states:

"In combat and emergency other considerations may justify the pilot in disregarding these limitations"

I was the one who told you that Operating Notes are mandatory to follow, linked to the airworthiness of the design, and done by convention.

They are very specific in what can and cannot be done. To include the specific passage the Air Ministry thought to include:

"In combat and emergency other considerations may justify the pilot in disregarding these limitations"

The only source you have are general aircraft notes given to all pilots in 1943? Next you will be saying that since part 3 gives information on the use and implementation of the Norden bombsight all hurricanes had a bomb aimer using the Norden! These are general aircraft notes, not aircraft or engine specific.