Westland Whirlwind revisited

[Wild_Bill_Kelso]

Since we are speaking in the third person here, some of you guys are really full of yourselves and drastically overestimate your own wisdom.

If everyone posting to this forum already agreed with all of your opinions, never made a single mistake, and never posted about anything for which they didn't already have an entire bookshelf of sources for ready to hand, this place would be as silent as a graveyard. Is that the goal?

 

[MIflyer]

Well, here is the summary of the Hawk 75 models from the old Profile publication. And note that the Hawk 75 export model were considered to have better aileron control than Spits.

Spitfire.

 

[Frog]

What about the 23 airframes that ended up on Martinique, alongside some ex-Belgian Brewster B339Bs?

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Here are some pics of the Brewsters:

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They were the part of the 395 H 75A-4 ordered from Curtiss.

As noted above, only about 6 arrived in France before June 40 and were not used in action.

They other did not arrive before the Armistice and were redirected to the French Antilles. 30 were lost at sea during shipment. 17 ended at Martinique island , 6 at Guadeloupe. island These H75A-4 were later delivered in Morocco after Operation Torch and were used as trainers in 1943 and 1944.

Those not shipped to the French were redirected to the British to become Mohawk IV.
The Mohawk III was the continuation of the French order for the H75A-III. The French received 60 examples, the surplus was rerouted to the British.

 

[Shortround6]

Since we are speaking in the third person here, some of you guys are really full of yourselves and drastically overestimate your own wisdom.

If everyone posting to this forum already agreed with all of your opinions, never made a single mistake, and never posted about anything for which they didn't already have an entire bookshelf of sources for ready to hand, this place would be as silent as a graveyard. Is that the goal?

You made a statement.
Many of us make statements. Many times I have been wrong.
When somebody corrects me I often look things up, before posting reply.
If I reply that I am right I try to bring sources or will provide them if requested.

True but IIRC they steeply ramped up the number of units flying these in early 1940

This was the 2nd post after I gave the beginning delivery dates (spring of 1939) which called into question the time line of most units not getting them until few weeks before the invasion.
Sorry I didn't post the book title, authors and date of publication for you.

You just doubled down with the "IIRC".

I use the "IIRC" a fair amount, in a first post/reply, if somebody says I am wrong then I will try to look it up. I don't use it as the 2nd step.
Maybe I am wrong about this. I dislike getting into arguments that bring no facts to the discussion.

There are certain people on this board that I will not question in certain areas because I figure their knowledge far exceeds mine.
I also make more than my share of typos so I don't try to score "points" on anybody for theirs and if I make a typo on number (like altitude or speed) and somebody calls me on it, then good, my spelling may suck but I want the numbers/facts to be correct. Let me correct it and thanks for pointing it out.

 

[MiTasol]

View attachment 712555
Breech of the guns came back through the notches in the instrument panel. Mighty long barrels to nearly reach the prop

The gun has a blast tube on it which is why it is so long.

I don't have any pictures of the P-36 and early P-40 guns but this is the later P-40 gun installation. Almost without exception, guns inside wings and cowls had blast tubes to extend the gun outside the structure otherwise the gun blast shock waves damaged the structure. I have no doubt that there are good photos of early P-40s showing the cowl blast tubes on the net.

 

[MIflyer]

Here is more on the Hawk 75. Including a drawing that amplifies MiTasol's above remarks.

 

[Wild_Bill_Kelso]

You made a statement.

My original comment was: "The P-36 pilots in France had the advantage of a few weeks to get familiarized with their aircraft, which I think helped a lot. D.520 pilots were thrown into the breach with little if any training on type. Same for the Bloch 150 series though those probably had more development work needed before they would be viable. "

This is basically true, except it was for a longer period than I realized.

Then you wrote "some hawk units had them since 1939" and I replied with IIRC etc. I wrote that because 1) It's what i thought was the case, admittedly not being an expert on the Battle of France, and 2) I wrote IIRC because I was not sure. And 3) I figured someone else here would correct me if i was wrong because I know there are some people active here who do know the French air force history quite well.

I have my little corners of WW2 aviation history that I do know quite well, and when I'm fairly certain something is true - and I have sources for it - I'll say so.

You apparently were not aware either that in fact almost all of the Hawk squadrons had them since Winter or Spring 1939. Or were you?

All of which is a very minor detail as to the point being made - French pilots and ground crew had more time to learn to fly (and maintain) the H75 than the D.520, upon which I think we both agreed. This in turn was a point which had veered off from a previous debate about whether the Whirlwind or the Hawk would have been effective for the British during the Battle of Britain, which I had been pointing out they were not suited for due to limited altitude performance. Another point where I think we agreed except possibly in some details.

Many of us make statements. Many times I have been wrong.
When somebody corrects me I often look things up, before posting reply.
If I reply that I am right I try to bring sources or will provide them if requested.

You are entitled to do so. I will do the same- when I have time, and if I have the resources. I don't have sources for the French Air Forces in the Battle of France, and i didn't have time to go looking, so I let it ride and made clear that i didn't know for sure. Again, that is what IIRC means. "If I recall correctly", the "I may not have" being implicit here.

This was the 2nd post after I gave the beginning delivery dates (spring of 1939) which called into question the time line of most units not getting them until few weeks before the invasion.
Sorry I didn't post the book title, authors and date of publication for you.

I never asked you to, I just wrote that I thought they had ramped up the number of squadrons later. Apparently I had confused that for the later delivery of the (much more capable) Hawk 75A3 in April 1940.

You just doubled down with the "IIRC".

Because of the reasons I outlined above. You made a sharp remark and I thought you were genuinely curious so I looked it up once someone listed the units, and then you got pointlessly snarky.

I use the "IIRC" a fair amount, in a first post/reply, if somebody says I am wrong then I will try to look it up. I don't use it as the 2nd step.

You often post a lot of vague stuff Shortround, it rarely bothers me. Usually your posts are interesting regardless, except when you get cranky.

Maybe I am wrong about this. I dislike getting into arguments that bring no facts to the discussion.

Sometimes there doesn't need to be an argument. I'm not sure how much it matters precisely how much time the French H75 pilots had to train, when the point being made was that they actually had time to train before going into combat, whereas the D.520 pilots more or less had to hit the ground running. Which appears to be correc.t

There are certain people on this board that I will not question in certain areas because I figure their knowledge far exceeds mine.
I also make more than my share of typos so I don't try to score "points" on anybody for theirs and if I make a typo on number (like altitude or speed) and somebody calls me on it, then good, my spelling may suck but I want the numbers/facts to be correct. Let me correct it and thanks for pointing it out.

I'm glad for my numbers (or dates) to be corrected if they are wrong too, but sometimes that comes along with a completely pointless extra dose of acid and given that as you note, we all make little mistakes on here (again, if we didn't, we'd have far less to discuss), I don't need to take that from anybody.

 

[Wild_Bill_Kelso]

I'm still glad to know all the extra data though, to be honest, I just don't need all the extra static about it.

 

[Jabberwocky]

Well, here is the summary of the Hawk 75 models from the old Profile publication. And note that the Hawk 75 export model were considered to have better aileron control than Spits.

Not just the Spitfire, the Hurricane as well.

The RAE tested the Hawk 75 vs the Spitfire, Hurricane and Gloster F.5/34 prototype over Dec-1939 and Jan-1940. They found that the Hawk 75 had much better alierons than any of the British types except the Gloster (and much better control harmony overall, which seems to have been a feature of US single engine fighters generally).

At high speeds (above 350mph) the Hawk could evade a Spitfire because it's pilot could make turns that the Spitfire simply didn't have the aileron authority to match. The Hawk could also evade at high speed by making aileron rolls to reverse direction, which again the Spitfire couldn't match.

The RAF took away the need to improve the Spitfire's roll performance and reduce the sensitivity of its elevator - which led to a lot of experimentation, and eventually introduction of light alloy aileron skins (replacing fabric) and the use of a bob weight on the elevator control system (which some pilots liked and others vehemently opposed).

 

[MIflyer]

Note that the original Hawk 75 units were the 1st, 2nd, 3rd, and 5th top scoring units in the French Air Force.

Seems like just about EVERYBODY flew Hawk 75's. The Mohawk IV R-1820 equipped versions originally ordered by the French had a lot of engine problems but it seems those problems were fixed because the RAF sent them to India where they flew in combat for years thereafter.

 

[Geoffrey Sinclair]

The 100 H-75A-1 and 100 H-75A-2 were built in the December 1938 to July 1939 period and it looks like all were exported before the war began., reported to be all in France by end August 1939.

According to the USAAF the next French order of 135 H-75A-3 serials 201 to 335 and 285 H-75A-4 serials 1 to 284 began production in February 1940, exports to France began in March and ended in June, by month 15, 67, 78, 56 total 216, 135 A-3 and 81 A-4, the rest going to Britain. The dates on the French shipping documents (SHAA 3B9 contract 37) say the last A-3 had reached the docks by 2 May 1940, overlapping with the first A-4 which had arrived on 25 April. If you want to pin down exactly when the ships arrived in France the documents give the ship names, also details like engine numbers.

A-3 shipments from the US
The Degrasse picked up 201 to 212, total 12. Bill of Lading dated 6 March 1940.
The Indo Chinois picked up 213 to 220, total 8. Bill of Lading dated 16 March 1940.
The Louis Louis-Dreyfus picked up 221 to 228, total 8. Bill of Lading dated 26 March 1940.
The Ile de Batz picked up 229 to 250, total 22. Bill of Lading dated 11 April 1940.
The Champlain picked up 251 to 284, total 34. Bill of Lading dated 13 April 1940.
The San Pedro picked up 285 to 289, total 5. Bill of Lading dated 18 April 1940.
The Leopold Louis-Dreyfus picked up 290 to 321, total 32. Bill of Lading dated 30 April 1940.

A-3/A-4 shipments from the US
The Ile de France picked up A-3 aircraft 322 to 334 along with A-4 2 to 5, 7, 8 total 13+6=19. Bill of Lading date 1 May 1940.
The Pierre Louis-Dreyfus picked up A-3 aircraft 335 along with A-4 6, 9 to 25, total 1+18=19. Bill of Lading date 10 May 1940.

A-4 shipments from the US
The Indo Chinois picked up aircraft 1, 26 to 58, total 34. Bill of Lading date 25 May 1940.
The Bearn picked up aircraft 59 to 64, 83, 85, 86, 88 to 90, 92 to 94, 96, 97, total 17. Bill of Lading date 15 June 1940.
The Jeanne d'Arc picked up aircraft 79 to 82, 84, 87, total 6. Bill of Lading date 15 June 1940.

I think all the A-3 were delivered to France and the Indo Chinois went to Casablanca, the Bearn to Martinique and the Jeanne d'Arc to Guadeloupe.

A-4 transfers to Britain, 65 to 78, 91, 95 and 98 onwards, total 204.

 

[wuzak]

The way to improve the Whirlwind is to use Hawk 75s?

 

[Wild_Bill_Kelso]

The way to improve the Whirlwind is to use Hawk 75s?

It started with a debate about the Whirlwind's altitude capabilities 'as-is' (without improvement) which veered into a comparison of the P-36 / Hawk 75 and it's altitude capability, and then that veered into Hawk 75 in the Battle of France

 

[Wild_Bill_Kelso]

Not just the Spitfire, the Hurricane as well.

The RAE tested the Hawk 75 vs the Spitfire, Hurricane and Gloster F.5/34 prototype over Dec-1939 and Jan-1940. They found that the Hawk 75 had much better alierons than any of the British types except the Gloster (and much better control harmony overall, which seems to have been a feature of US single engine fighters generally).

At high speeds (above 350mph) the Hawk could evade a Spitfire because it's pilot could make turns that the Spitfire simply didn't have the aileron authority to match. The Hawk could also evade at high speed by making aileron rolls to reverse direction, which again the Spitfire couldn't match.

The RAF took away the need to improve the Spitfire's roll performance and reduce the sensitivity of its elevator - which led to a lot of experimentation, and eventually introduction of light alloy aileron skins (replacing fabric) and the use of a bob weight on the elevator control system (which some pilots liked and others vehemently opposed).

I think this may be key to the Hawk's success - escape maneuvers relying on the same traits were described being used with P-40s against the Bf 109 and the A6M, both of which experienced some control stiffening at higher speeds. Unfortunately the Ki 43 did not experience this kind of problem, but they were a bit slower.

If there is an effective escape maneuver that the Hawk pilots can use against the Bf 109, that explains perhaps why it may have been useful. It also had a fairly high dive speed which the Finns may have been able to use against the earlier Soviet fighters.

Speaking of which, I believe, actually I am pretty sure, that i read somewhere in this forum, I don't remember where or by who, that there was a British test that indicated the Hawk 75 could actually out turn the Ki 43 which is damn impressive if it's true. Very good turn rate + high roll rate + an escape maneuver means increased viability IMO.

 

[Wild_Bill_Kelso]

Note that the original Hawk 75 units were the 1st, 2nd, 3rd, and 5th top scoring units in the French Air Force.

Seems like just about EVERYBODY flew Hawk 75's. The Mohawk IV R-1820 equipped versions originally ordered by the French had a lot of engine problems but it seems those problems were fixed because the RAF sent them to India where they flew in combat for years thereafter.

They changed engines on Hawks a lot though didn't they? Did the Mohawk IVs (Hawk 75 A4?) used in India still have the 1940 engines meant for France?

 

[GregP]

Note that the original Hawk 75 units were the 1st, 2nd, 3rd, and 5th top scoring units in the French Air Force.

Seems like just about EVERYBODY flew Hawk 75's. The Mohawk IV R-1820 equipped versions originally ordered by the French had a lot of engine problems but it seems those problems were fixed because the RAF sent them to India where they flew in combat for years thereafter.

View attachment 712712View attachment 712713View attachment 712714

Here's one I drew:

Generic Hawk, nothing specific. Oops, I see that in the side view, I need to move the gun fairing upward in the layer ... done, but I won't re-post just for that.

 

[Frog]

They changed engines on Hawks a lot though didn't they? Did the Mohawk IVs (Hawk 75 A4?) used in India still have the 1940 engines meant for France?

The French H75A-4 were equipped with 1200 HP Wright R-1820 G 205A engines. The 251 ex French Mohawk IV retained the same engine.

 

[Wild_Bill_Kelso]

Here's one I drew:

View attachment 712757

Generic Hawk, nothing specific. Oops, I see that in the side view, I need to move the gun fairing upward in the layer ... done, but I won't re-post just for that.

That's brilliant!

 

[Wild_Bill_Kelso]

The French H75A-4 were equipped with 1200 HP Wright R-1820 G 205A engines. The 251 ex French Mohawk IV retained the same engine.

That would make sense for the A-4s I think, probably that was the best engine wasn't it? Did anyone get any of the earlier H75s? The Finns got some A3s right? I think I read of some engine swaps in Finland.

 

[EwenS]

Here is more on the Hawk 75. Including a drawing that amplifies MiTasol's above remarks.

View attachment 712624View attachment 712619View attachment 712620View attachment 712621View attachment 712622View attachment 712623

The Air Enthusiast article contains a typo.

155 squadron operated the Mohawk IV between August 1942 and January 1944. So the line in the right hand column, second last para of p52 should read "By the end of 1943...." not 1944. It then converted to Spitfire VIII.