Rolls Royce Heritage Trust, 296 Peregrine built February 1940 to January 1942. Rolls Royce apparently made the claim the RAF could have 1 Peregrine or 2 Merlin. Ministry of Aircraft production, 114 Whirlwind built June 1940 to January 1942.
AIR 16/326
Squadron leader Munro, Whirlwind report after 7 months service use. Gentleman's airplane, pilots with no twin engine experience and around 10 hours on Hurricanes are going solo without any preliminary dual training, no accidents. Take off good, climb exceptional to 10,000 feet, very good to 20,000 feet, to 30,000 feet 3 to 4 minutes slower than a Hurricane I. Faster than the Spitfire below 10,000 feet about the same 10 to 20,000 feet, faster than a Hurricane at 30,000 feet. Dives almost too well, better manoeuvrability at 360 mph IAS than the Hurricane and Spitfire, use energy tactics to fight. Aerobatics good and easy to perform, slots help manoeuvrability but their drag above 20,000 feet is a problem. Undercarriage excellent. Single engine flying exceptionally good. Cockpit roomy, well laid out, efficient heating and cooling, view forward very good, to rear hindered by armour plate, so being slightly better than a Hurricane or Spitfire. Very steady gun platform, viewable area helps deflection shooting. Normal serviceability is high but dragged down by inexperienced pilot's accidents and bad patches in airfields. Engines very smooth and start well but do not give their rated boost at altitude. Confident a Whirlwind could be landed at 45 pounds per square foot loading.
Single seat day and night fighter. 31 July 1940, L6845 at 10,072 pounds (tare 8,005, light weight 7,613, fixed military load 393, service load 956 pounds, 1,020 pounds of fuel at 7.7 pounds per gallon, 90 pounds of oil). Engine ratings 860 BHP at rated altitude of 13,500 feet at 2,850 RMP at 6.75 pounds per square inch boost. Rate of climb 2,715 feet/min 2,000 feet (reached in 0.8 minutes) to 10,000 feet (3.7 minutes), 2,310 feet/min at 15,000 feet (5.7 minutes), 1,585 feet/min at 20,000 feet (8.2 minutes), 860 feet/min at 25,000 feet (12.4 minutes), 145 feet/min at 30,000 feet (24.6 minutes), service ceiling estimated 30,300 feet. Take off run 375 yards, to clear 50 foot obstacle 710 yards. Speed 351 mph at 15,000 feet, 354 mph at 15,800 feet (Full throttle height for +6.75 pounds boost), 342 mph at 20,000 feet. Under test conditions, 4.3 mph wind, temperature 19 degrees C, barometer 29.81 inches Hg, take off run 365 yards, to clear 50 food obstacle 660 yards, landing run 635 yards. Mainplanes area 250 square feet gross, 231 square feet nett, loading at 10,700 pounds 40 pounds/square foot gross, 43.5 nett. Wing constructed in 3 sections, fabric covered control surfaces.
Another weight diagram says 136 gallons of fuel at 7.5 pounds per gallon = 1,020 plus 10 gallons of oil at 9 pounds per gallon. Weights, crew plus parachute 200 pounds, Gun load fixed 74 pounds, service load 650 pounds, pyrotechnic load 6.5 pounds fixed, 36 pounds service, electrical load fixed 192 pounds, instrument load 80.5 pounds fixed, 15 pounds service, wireless load 8.5 pounds fixed, 52.5 pounds service, miscellaneous 31 pounds fixed, 3 pounds service, all up 392.5 pounds fixed military load, 956.5 pounds service load.
February 1940, The fuel tanks form the wing skin, special long range tanks reported available to allow around 1,400 miles range at 200 mph.
1 July 1940, Dowding to Beaverbrook, only have 3 Whirlwinds, pilots like them (but they came from Blenheims), given the problems with Lysanders expect plenty of problems, 2 engines to lift 4 cannons is excessive when the new Hawker fighter will lift 6 with 1 engine, may be glad to have them as anti tank and bomber destroyers but glad to drop them when the new Hawker fighter enters production. Note these are first impressions only, do not quote them against me.
24 September 1940, defect report, Carburettors, Slat sprockets, wing tips, fuselage nose portion, hydraulics, engines. The engines giving little trouble, defects with exactor throttle and mixture controls, boost pressure variations under investigation. Engine failure in air due to Bostick cement in fuel filter, the company using the compound to internally seal the fuel tanks. Westland not moving quick enough to fix problems.
25 September 1940, impossible to properly maintain instrument panel through the loading door, a larger trap door to be provided on the 19th aircraft and retrospective action taken. Flap and undercarriage controls to move to new Air Ministry standard. Extractor controls seem good, boost problems are due to the mechanism in the engine. Faulty fuel tanks leaking. Wing tips failing, bad workmanship. Slat modifications. Carburettor intake too long and complicated, a less complicated design would cost 5 mph. Eleventh and later aircraft to have one piece cockpit coupes. Fuselage nose piece strengthened, majority of hydraulic problems due to badly fitted pipes, flexible pipes being experimented with. Currently ignition timing requires removal of propeller, trap door to be fitted for access to engine timing plug. Spare parts are a problem.
17 October 1940, Dowding to Beaverbrook, the "I know Westlands and I know the packet of trouble the [263] squadron would be in for" letter. Dowding states he did not know Peregrine production was coming to an end, he last heard 200 Whirlwinds at 2 per week on order.
27 November 1940, Sholto Douglas To Petter 263 squadron to Exeter to have Whirlwinds, but Westland seems to be concentrating on building irrelevant Lysanders instead of much wanted Whirlwinds.
Quentin Brand to Sholto Douglas, 3 March 1941, Whirlwind, unsatisfactory manoeuvrability, linked flap and radiator controls a problem for go arounds, cockpit must be closed during flight, 200 hours to change the mainplane outboard of the engine, and 3 to 4 days to change an engine. Prefer no extension of Whirlwind use.
14 March 1941 Sholto Douglas to Under Secretary of State, indifferent performance about 20,000 feet, poor manoeuvrability, closed cockpit in flight, rear view no better than the Spitfire and Hurricane, linked flap and radiator controls a problem for go arounds, 200 hours to change the mainplane outboard of the engine, and 3 to 4 days to change an engine. Prefer no extension of Whirlwind use, one or two squadrons employed outside enemy fighter range is enough.
Undated Whirlwind II proposal, 60 more gallons of fuel (all in tank mid way between cockpit and tail?). 31 gallons/15 minutes take off and climb, 19 gallons/25 minutes at 220 mph to target area, 55 gallons/35 minutes patrol and action at an average 310 mph, 19 gallons/25 minutes at 220 mph return, 10 gallons for 15 minutes reserve. Going from 134 to 194 gallons of fuel increases the target area patrol and action to 115 gallons/75 minutes. Other improvements to raise top speed to around 380 mph. In a climb the Whirlwind is faster than a Spitfire until 27,500 feet where the times are equal at about 13.5 minutes but the Spitfire takes about 17 minutes to 30,000 feet the Whirlwind about 24.
AVIA 46/122
First prototype first flown 11 October 1938, second prototype 29 March 1939. Delay due to new design features plus, 3 month delay in engine delivery (February to May 1938), 3 month delay in undercarriage delivery, 3 month delay in oil cooler delivery, numerous small installation difficulties around July 1938, failure of Simmonds controls, replaced by Exactor, failure of a hiduminim casting in August 1938. Brief handling trials report, excellent fighter and exceptionally easy to fly. First prototype had handed engines, not the second, which was fitted with bullet proof windscreen and full armament. Tests showed practically no difference between having handed and non handed engines installed.
The order for 200 was only placed after the prototype had flown but whether handed engines were to be installed remained an issue, Westland pressed strongly on Spring 1940 for handed engines. The delay of the engine decision was a main reason the original promise of 9 months from order to delivery did not happen, becoming around 18 months, the time line for the second prototype has an entry "delivery of engines becomes a matter of urgency". Along with this Westland was trying for few changes, the Air Ministry noting the delays and wanting an up to date version requiring many changes. The compromise was many changes from the 25th aircraft onwards, after the firm was rapped over the knuckles about its estimates on the delays the changes would cause. The firm neglected the need for advanced notification of equipment requirements, not good in the 1940 crisis. The decision to cut Peregrine production was made in "the middle of the Battle of Britain" [Westland was informed on 8 May about this]. "The aircraft was incapable of development because the structure was neither roomy enough nor strong enough to take larger and more powerful engines."
The only development of the Whirlwind was the fighter bomber modification. Requested on 3 July 1942, approved on 9 July, tests done by 9 September. A pair of 500 pound bombs under the wings, a simple modification being done by unit personnel assisted by Westland engineers. On 6 December approval for universal carriers to carry 250 or various 500 pound bombs, 50 sets of parts being made.
Peregrine production schedule was 8 in February 1940, 12 in March, 22 in April rising to 48 in December, actual production was 3, 1 and 10 then 21 in December.
First Whirlwind production order for 200 on 18 January and 200 more on 5 April 1939? First production delivery 15 June 1940, second 13 July, by 20 July a total of 4 deliveries.
RAF Census End February 1943, 33 operational Whirlwind plus 3 others in Fighter Command, 15 in the maintenance system, 2 instructional airframes, 62 lost, 1 foreign power = P6994 to USA, shipped 5 June 1942, total 116 including the 2 prototypes. End June 1944, 18 in maintenance system, 2 instructional airframes, 93 lost, 1 foreign power, total 114 production examples.