View Full Version : Curtiss Hawk 75 Performance.

05-26-2012, 05:50 PM
Trying to find numbers other than basic performance tests is daunting for this aircraft. Still I have stumbled on some interesting things...

A post over at UBI from 2006. Check horseback's post about Hawk 75 testing by the RAE in Britain.


I'll quote it here...

From Green & Swanborough's US Army Air Force Fighters, Part 1, part of Arco's WW2 Aircraft Fact Files, published in the mid-seventies:

"The Curtiss fighter was by no means an unknown quantity to the RAF, for as early as November 1939 a Hawk 75A-1 had been flown (in France) by Sqn Leader J F X McKenna on behalf of the A and AEE. His report had said that the Hawk was "exceptionally easy and pleasant to fly, the aileron control being particularly powerful" and that it was "more manoeuvrable at high speed than the Hurricane or Spitfire". This report naturally aroused considerable interest in official circles in Britain, and as a result arrangements were made for a Hawk 75 to be borrowed from l'Armee de l'Air for further evaluation in Britain. The 88th Hawk 75A-2 was used, in consequence, at the RAE from 29 December 1939 to 13 January 1940 for a 12-hr flight programme covering handling in general, and specificallyby comparison with the Spitfire, Hurricane and Gloster F.5/34; mock combats were staged between the Hawk and a production Spitfire I (K9944), fitted with the early two-pitch propeller (3-bladed De Havilland two-speed prop-HB).

"The Hawk 75A-2 was flown with aft tank empty at a loaded weight of 6,025 lb (2 733 kg) and the three RAF pilots participating in the evaluation were unanimous in their praise for the US fighter's exceptional handling characteristics and beautifully harmonised controls. In a diving attack at 400mph (644 km/h) the Hawk was far superior to the Spitfire, thanks to its lighter ailerons, and in a dogfight at 250 mph (402 km/h) the Hawk was again the superior machine because of its elevator control was not over-sensitive and all-around view was better; but the Spitfire could break off combat at will because of its very much higher maximum speed. In a dive at 400 mph (644km/h), the Spitfire pilot, exerting all his strength, could apply no more than one-fifth aileron because of high stick forces whereas the Curtiss pilot could apply three-quarter aileron.

"When the Spitfire dived on the Hawk, both aircraft travelling at 350-400 mph (560-645 km/h), the Curtiss fighter's pilot could avoid his opponent by applying its ailerons quickly, banking and turning rapidly. The Spitfire could not follow the Hawk round in this manoeuvre and consequently overshot the target. In the reverse situation, however, the Hawk could easily follow the Spitfire until the latter's superior speed allowed it to pull away. The superior manoeuvrability of the Hawk was ascribed mainly to the over-sensitiveness of the Spitfire's elevator, which resulted in some difficulty in accurately controlling the 'g' in a tight turn; over-correction held the risk of an inadvertent stall being induced.

"Because of the difference in propellers, the Hawk displayed appreciably better take-off and climb characteristics. The swing on take-off was smaller and more easily corrected than on the British fighter and during the climb the Hawk's controls were more effective; but the Curtiss fighter proved to be rather slow in picking up speed in a dive, making the Spitfire the more suitable machine of the two for intercepting high-speed bombers (which was, of course, the primary role for which the British aircraft had been designed).

""Notwithstanding the excellence of this report on the Hawk 75A-2's handling, the RAF found little use for the Mohawks that began to arrive in Britain a few months later. Upon arrival, they were modified to have British throttle movement, six Browning 0,303-in (7,7-mm) machine guns, British gun sight, instrumentation and radio and standard RAF day fighter finish. Apart form one or two assigned to the A & AEE Boscombe Down for the preparation of handling notes, they were then dispatched to various MUs for storage..."

Some basic numbers taken from Curtiss Fighter Aircraft A Photographic History 1917~1948 by Francis H. Dean and Dan Hagedorn for the US Army P36C:

Pratt & Whitney R-1839-17 (S1C-3G) rated at 1200bhp for takeoff and 1050bhp @ 7500ft. These used 100 octane fuel. The earlier Twin Wasps of the A used 90 octane, and the earliest development aircraft ran on 87 octane.

Performance of the C was maximum 311mph @10,000ft. Time to 15,000ft of 4.9 minutes. Service ceiling 33,700ft. (I'll bet it was a dog up there...)

Another reference I have from the same book, shows 313mph @ 2700rpm @ 8500ft. for the A model with the -17 engine and 100 octane fuel.

Landing speed 75 mph.

Stall speed 69mph

3400 ft./min climb rate

Time to 15,000ft. 4.8 min.

BTW, It would appear that the P36's in US Army service had a much higher rate of climb than a P 40. Not sure about power setting used on P-36 tests as it is not listed, but P40s tested at Military Power had initial climb rates of 2000ft./min.

The search continues...

05-26-2012, 05:55 PM
Thanks, keep digging! Links from wikipedia are good, too:

Hawk Specification (http://www.scribd.com/doc/69325114/1938-Detail-Specifications-for-Curtiss-Hawk-75-A-Airplane)
Small article (http://books.google.de/books?id=UtwDAAAAMBAJ&pg=PA506&dq=Popular+Science+1933+plane+%22Popular+Mechanics %22&hl=en&ei=o1oqTvn6BtCEsAKCuOSsCw&sa=X&oi=book_result&ct=result&redir_esc=y#v=onepage&q=Popular%20Science%201933%20plane%20%22Popular%20 Mechanics%22&f=true)

06-01-2012, 05:37 PM
I wish we could talk to this guy...


I think that's the only flyable Hawk 75 there is.

06-01-2012, 06:06 PM
I saw this plane flying in Duxford years ago. Seemed like a nice dog fighter. No idea of speed, climb and other performance figures.

Once you see those real planes in air you notice what kind of problems there are in how the sim planes fly. At least when flown by AI pilots. Like in IL2 many multi engine planes do all sorts of fighter moves, when IRL big planes fly very differently.