Spit IIa is now so much more inferior to the 109

[41Sqn_Banks]

Originally Posted by camber

However it is very unlikely that pilots were ever authorised to use the unmodified boost cutout as emergency power because the risk of instant degradation of engine performance was high (especially at low altitudes)

Absolutely correct. In fact the were not authorized.

[Crumpp]

Absolutely correct. In fact the were not authorized.

So the argument that the airworthiness limitations were free to be violated because the RAF says to balance risk only works when it fits an agenda?

[41Sqn_Banks]

Originally Posted by Crumpp

So the argument that the airworthiness limitations were free to be violated because the RAF says to balance risk only works when it fits an agenda?

Where does RAF authorities allow to ignore/violate engine limitations? My agenda is to follow primary sources, this makes life pretty easy.

[Seadog]

Originally Posted by Crumpp

So the argument that the airworthiness limitations were free to be violated because the RAF says to balance risk only works when it fits an agenda?

We know your agenda.

The RAF's agenda was to provide the pilot with the best possible performance in high risk combat situations. The RAF didn't want to provide the pilot with an engine self destruct switch, which is what would happen if the boost override was used with 87 octane fuel.

[fruitbat]

Originally Posted by Seadog

We know your agenda.

The RAF's agenda was to provide the pilot with the best possible performance in high risk combat situations. The RAF didn't want to provide the pilot with an engine self destruct switch, which is what would happen if the boost override was used with 87 octane fuel.

+1

Its just Crumpp trying to ignore all the pilot accounts regarding using the boost ie pulling the plug etc,being linked to 100 octane fuel because it doesn't fit with the agenda he's pushing.

[Crumpp]

Where does RAF authorities allow to ignore/violate engine limitations?

In the General Pilots Notes it states the pilot can balance risk and exceed the published limitations. That was the clause used to advance the idea in the 100 Octane thread that the RAF pilots routinely violated the Notes on a Merlin Engine in the Operating Notes.

My agenda is to follow primary sources, this makes life pretty easy.

Mine too. That is why I bring the point up you cannot look at a combat report as proof of 100 Octane use with specific references to +12lbs or 100 Octane.

The RAF didn't want to provide the pilot with an engine self destruct switch

Obviously the RAF was comfortable enough to test it at 12,500 feet on 9-6-39 Merlin III serial number 7491 mounted on Spitfire N3171 up +10.55lbs using 87 Octane fuel.

[41Sqn_Banks]

Originally Posted by Crumpp

In the General Pilots Notes it states the pilot can balance risk and exceed the published limitations. That was the clause used to advance the idea in the 100 Octane thread that the RAF pilots routinely violated the Notes on a Merlin Engine in the Operating Notes.

Paragraph number please. I don't like to read the whole manual to find one sentence.

[Crumpp]

Paragraph number please.

Part I Introductory of the General Flying Notes.

[lane]

Originally Posted by Crumpp

Obviously the RAF was comfortable enough to test it at 12,500 feet on 9-6-39 Merlin III serial number 7491 mounted on Spitfire N3171 up +10.55lbs using 87 Octane fuel.

You've got that all scrambled. N3171 hadn't even flown yet on 9-6-39. The power figures on the engine Inspection and Test Certificate come from "test bed conditions", either at RR, RAE or the dynamometer at AAEE, i.e. the engine wasn't even mounted in an airframe and the engine surely wasn't running at 12,500 feet without an airframe.

[Al Schlageter]

N3171 Ia 413 EA MIII

FF 10-11-39
27MU 13-11-39
AMDP 16-11-39
AAEE 19-3-40 comparison perf trials (Rotol constant-speed prop) with K9793 (2-blade fixed pitch)
CFS 24-2-40 ? for compilation of pilot's notes
ECFS Hullavington 13-6-42
SOC 18-8-45