Author Topic: Prepare to HO! (Read 1401 times)

Karnak · « **Reply #15 on:** September 07, 2006, 09:55:35 AM »

The ammo load is light.

Four Hispano Mk Is with 60 rounds per gun.

Furball · « **Reply #16 on:** September 07, 2006, 11:58:12 AM »

Quote

Originally posted by Debonair
iirc think they were in a sucessor plane, but the design ran into low critical Mach number trouble at high alts & speeds so i guess it probably had even worse trans-sonic troubles that the P-38...

The Welkin was a very high altitude interceptor based on the fueselage of the Whirlwind. The Whirlwind was a low altitude attack aircraft.

Very different aeroplanes.

The Whilrwind first flew in 1938, and was very fast at low alt (Around 360 mph) when the RAF's other front line fighter the Hurricane was managing 330 mph or something.

Angus · « **Reply #17 on:** September 08, 2006, 03:10:47 AM »

Fast down low + agile + 4 nose mounted Hizookas = NOT hangar queen I guess

frank3 · « **Reply #18 on:** September 08, 2006, 08:43:24 AM »

Quote

Originally posted by Karnak
The ammo load is light.

Four Hispano Mk Is with 60 rounds per gun.

Would probably be enough for dogfighting, but not for strafing/buff-hunting

GtoRA2 · « **Reply #19 on:** September 08, 2006, 05:24:34 PM »

I read somewhere the reason merlins were never tried is the airframe was to weak to take the strain.

Anyone else hear that?

HoHun · « **Reply #20 on:** September 08, 2006, 05:50:35 PM »

Hi Furball,

>The Whilrwind first flew in 1938, and was very fast at low alt (Around 360 mph) when the RAF's other front line fighter the Hurricane was managing 330 mph or something.

Here is a short analysis of Whirlwind performance I prepared a while back. Lacking good data, I had to guess some parameters, so this is no high-fidelity stuff:

http://hometown.aol.de/HoHunKhan/Whirlwind_Speed.png

http://hometown.aol.de/HoHunKhan/Whirlwind_Climb.png

Regards,

Henning (HoHun)

Furball · « **Reply #21 on:** September 09, 2006, 04:11:39 AM »

that's cool, thanks for that HoHun

surprisingly good climbrate, 3,000+ fpm up to 4,000m

HoHun · « **Reply #22 on:** September 09, 2006, 07:37:23 AM »

Hi Furball,

>surprisingly good climbrate, 3,000+ fpm up to 4,000m

Roger that, the Peregrine engine combined with a compact and light airframe really paid off there :-)

I updated the graphs to show the Whirlwind's German counterpart, too:

http://hometown.aol.de/HoHunKhan/Whirlwind_Speed.png

http://hometown.aol.de/HoHunKhan/Whirlwind_Climb.png

As you can see, the Whirlwind easily out-performed the Fw 187A-0 powered by a Jumo 210, an engine of the same generation as the Peregrine (though closer to the older Kestrel in power).

This is a reflection of the design philosophy of the two aircraft: The Whirlwind was really designed for the Kestrel/Peregrine class engines, and the Fw 187 was meant for the DB600/DB601 class engines that were new back then.

Though Whirlwind and Fw 187 look suprisingly similar at first sight, the Whirlwind is in fact a lot smaller, with about 2 m less wingspan and just 75% of the Fw 187's wing area. As a result, the Fw 187 was heavier, but it could take the DB601-class engines, while the Whirlwind could not take the equivalent Merlin-class engines without a complete redesign (which was considered, but rejected).

Another difference is that the Whirlwind was built for a heavy cannon armament from the outset, as clearly visible in the above photograph :-) The Fw 187 started with four rifle-calibre machine guns, which was weak armament even back then.

Regards,

Henning (HoHun)

Furball · « **Reply #23 on:** September 09, 2006, 07:44:45 AM »

Thank you HoHun.

The redesign being the Welkin hi alt interceptor?

Would have been interesting if they had fit the Whirlwind with another new wing optimised for low alt, its performance certainly seems far better than the Beaufighter.

I suppose the role in which it excelled was taken by the introduction of the Typhoon (and of course Mosquito), so there would have been no point in a time consuming and costly redesign.

Angus · « **Reply #24 on:** September 09, 2006, 08:01:39 AM »

So, it would be up for the MA

HoHun · « **Reply #25 on:** September 09, 2006, 10:10:12 AM »

Hi Furball,

>The redesign being the Welkin hi alt interceptor?

No, the re-design was never accomplished. The Welkin was a new aircraft that did share the same general layout with the Whirlwind, not a direct re-design.

>Would have been interesting if they had fit the Whirlwind with another new wing optimised for low alt

Hm, I have found mention of the Whirlwind wings as being NACA 23xxx profiles, which are good all-around and were used on many WW2 aircraft, including the Fw 190. If that's correct, the Whirlwind's wing was probably OK.

>I suppose the role in which it excelled was taken by the introduction of the Typhoon (and of course Mosquito), so there would have been no point in a time consuming and costly redesign.

I believe the Whirlwind was originally designed as four-cannon interceptor, and with engines becoming more powerful, it became possible to mount four cannon on a single-engined fighter, too, so there was no reason left to go for the additional complexity and cost of a twin.

Regards,

Henning (HoHun)