Spitfire & Hurricane flight model & engine performance thread. (1.09 patch)

[Kurfürst]

Originally Posted by trademe900

OK well, at step forward at last as of the patch on the 12th!

New problem however- Spit 2 under-performs in comparison to 1a 100 octane.

Historical I am afraid...

[Osprey]

Depends what you are talking about Kurfurst. In top speed at particular altitudes then yes, but in climb absolutely not.

[Kurfürst]

I mean speed. The Mk II was cleared for +9, the Mk I for +12 in emergency during BoB, so at low levels the Mk I is of course a bit faster.. but I did not test the new patch yet, though I heard that the 100 octane RAf planes are finally fixed speed wise, yes?

[Robo.]

Originally Posted by Kurfürst

I mean speed. The Mk II was cleared for +9, the Mk I for +12 in emergency during BoB, so at low levels the Mk I is of course a bit faster.. but I did not test the new patch yet, though I heard that the 100 octane RAf planes are finally fixed speed wise, yes?

The Merlin XII was also cleared for +12. Not that I disagree with you regarding top speed at S/L at +12 vs +9lbs. boost.

I wonder what klem will say after he will test the new FMs. Sounds like good news though so far.

[Kurfürst]

I think it was discussed and shown that +12 combat rating was cleared for the Merlin XII only well after BoB, though there was some sort of take off rating that was pretty much useless for anything else but to shorten takeoff.

[Al Schlageter]

Originally Posted by Kurfürst

I think it was discussed and shown that +12 combat rating was cleared for the Merlin XII only well after BoB, though there was some sort of take off rating that was pretty much useless for anything else but to shorten takeoff.

The BoB was just starting in July 1940.

The Spitfire II Pilot Notes, dated July 1940, say 12lb boost can be used to 10,500ft. A boost of 12.5lb can be used for take off to 1,000ft.

http://www.zenoswarbirdvideos.com/Im...pit2Manual.pdf

[JtD]

I'm afraid zeno is inaccurate here. I think I have the Spitfire II pilot notes without any amendments, at least the amendment list is there and empty. This should be the original version dated July 1940. In there, the engine limitation for all out level is 9lb boost.

It appears that the all out level increase was at latest added with amendment list 31 / L, at a date that is not known to me.

The zeno version is missing the amendment list and does not shed any light on the "when".

[fruitbat]

Originally Posted by Kurfürst

I think it was discussed and shown that +12 combat rating was cleared for the Merlin XII only well after BoB, .

No it wasn't.

No one knows what date the amendment was from the discussions here, and you can't say with any certainty when it was cleared without the date of the amendment, all we know is it was after july'40 sometime.

It could of been in September for all we know or well after BoB, without the date, its just speculation, so don't spread you want to believe as fact.

[41Sqn_Banks]

First documented use of emergency boost with a Spitfire II is 21 August: http://www.wwiiaircraftperformance.o...-21aug40-1.jpg

Double standard view on the subject:

The use of +12 in Spifire II is
a) documented in combat reports as "emergency boost" 8 days after the first operational use
b) authorized in a later edition of the manual
c) the cut-out is mentioned in the earliest edition of the manual for emergency use. Without a specific modification to +12 boost the cut-out would enable the pilot to obtain any boost up to +17
Invalid. Not enough proof, even if there is nothing that prevents the pilot from using it. The combat report doesn't mention +12 boost, maybe the pilot used the cut-out to obtain the regular boost +9 manually instead of simply moving the throttle full forward.

On the other hand there is 1.4/1.45 ata for DB601A which
a) is restricted to take-off in any edition of the manual
b) is not mentioned by any pilot report for anything else than take-off
Valid. There is nothing that prevents the pilot from using it in combat.

[trademe900]

Originally Posted by Kurfürst

though I heard that the 100 octane RAf planes are finally fixed speed wise, yes?

Not really.

Spitfire is only the same speed as the Hurricane at altitude now (320mph at 18,000 feet), it is still very slow.

At sea level they are all good though.