Towards the Spitfire and the Hurricane

[PMN1]

Following their proposals for the F.7/30 specifications both Hawkers and Supermarine improved on the aircraft with Hawker proposing the Hawker monoplane and Supermarine proposing two designs that eventually turned into the Spitfire we know.

All designs were initially Goshawk powered although the Hawker monoplane was also offered in a Mercury version.

What changes happened for Hawker and Supermarine to be able to offer these new designs?


http://img.photobucket.com/albums/v136/paul1/HawkerMonoplane.png

http://img.photobucket.com/albums/v136/paul1/OriginalSupermarineType300.png

[Wuzak]

I suspect the thing that "changed" was that the designs were rejected in favour of biplanes, and that performance was below par.

I also think that the experience gained on the earlier projects encouraged the companies to be bolder in their designs.

I think the drawer got the plan view of the Supermarine Type 300 wrong - the exhaust stacks appear to be pointed in the wrong direction...

[Trexx]

I noticed the exhaust ports going the wrong direction too. It's interesting the Spitfire prototype had flush mounted exhaust pipes for extra clean aerodynamics. Later, someone figured out that escaping exhaust gases could be vectored rearward to help propel the airplane!
Who was the bloke that swerved into that idea?

Another question gentlemen, where do you get the "specification nomenclature". Those that specify certain airplanes to build such as "F.7/30" ?

[Wuzak]

F.7/30 meant, I think, the 7th fighter specification for calendar year 1930.

B was for bombers, and P was for medium bombers (I think), etc.

[Wuzak]

It may also be that the number of the specification was not linkedt o the aircraft category, so F.7/30 was the 7th specification, of all types, issued in 1930.

An example of this would be B.12/36 which lead to teh Supermarine 316 and the P.13/36 which led to the Lancaster and Halifax.

[Kutscha]

I think the drawer got the plan view of the Supermarine Type 300 wrong - the exhaust stacks appear to be pointed in the wrong direction...

There are several 3 view drawing in Spitfire: The History and they all have forward facing exhaust stacks.

The drawing posted was for Spec F7/30 not Spec F37/34 Type 300.

[PMN1]

Another question gentlemen, where do you get the "specification nomenclature". Those that specify certain airplanes to build such as "F.7/30" ?

The wiki article says it how I thought it worked

http://en.wikipedia.org/wiki/List_of_Air_Ministry_specifications

[PMN1]

There are several 3 view drawing in Spitfire: The History and they all have forward facing exhaust stacks.

The drawing posted was for Spec F7/30 not Spec F37/34 Type 300.

Wasn't the F.7/30 Supermarine design the gull winged design with fixed undercarriage?

[Kutscha]

Sorry, was for the revised F.7/30. (It is 03:00 here)

[Lightning]

Hi Trexx,

I noticed the exhaust ports going the wrong direction too. It's interesting the Spitfire prototype had flush mounted exhaust pipes for extra clean aerodynamics. Later, someone figured out that escaping exhaust gases could be vectored rearward to help propel the airplane!


This was an early attempt at "reverse thrust" to enable the aircraft to shorten its landing roll. :D

Regards,

Lightning

[Wuzak]

There are several 3 view drawing in Spitfire: The History and they all have forward facing exhaust stacks.

The drawing posted was for Spec F7/30 not Spec F37/34 Type 300.

The plan has forward facing exhasut stacks but the side profile does not.

[Kutscha]

The plan has forward facing exhasut stacks but the side profile does not.

It is a terrible scan. In the book, the profile definitely shows the exhaust being forward.

[Lightning]

It is a terrible scan. In the book, the profile definitely shows the exhaust being forward.

If the exhaust stacks did, in fact, point forward, I am at a loss to understand why. It seems to me that this would cause an unwanted additional back pressure in the exhaust system--especially at high speeds. I guess there must have been a reason for this arrangement. Can anyone explain what it might be?

[Red Admiral]

From the couple of planes fitted with Goshawks that I've looked at, there isn't an apparent air intake for the rear mounted supercharger. It almost seems like there isn't a supercharger, just six direct carbs each feeding two cylinders. Of course, this does beg the question of where the exhaust is.

[Lightning]

Hi All,

Quoting myself:If the exhaust stacks did, in fact, point forward, I am at a loss to understand why. It seems to me that this would cause an unwanted additional back pressure in the exhaust system--especially at high speeds. I guess there must have been a reason for this arrangement. Can anyone explain what it might be?

In addition, the thrust of the forward-directed exhaust would work to slow the plane down. This whole arrangement seems to be detrimental to performance.

Regards,

Lightning