m10bob
Posts: 8622
Joined: 11/3/2002
From: Dismal Seepage Indiana
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318 MPH
http://olympicflightmuseum.com/aircraft_gallery/f4f_01.htm
Of course, you must realize atmospherics and avgas quality, maintenance standards and hours on the airframe are factors as well, so I would accept this figure as a very good generic answer, and yeah, I am somewhat of an aviation grognard, from that era.....
and for detail and comparisons:
The Bell P-39 and Grumman F4F-4 are key points of comparison and merit brief comment. The maximum speed of the P-39D is generally cited as 360 m.p.h. at 15,000 feet (Dial, p. 272). That for the F4F-4 is given as 318 m.p.h. at 19,400 feet (Taylor, p. 501) or as more pertinent here 274 m.p.h. at sea level (Baugher). The F4F-4 engaged the Zero in both carrier battles and in numerous combats over Guadalcanal operating from land bases. The P-39D (and its P-400 export version) operated against the Zero both over Guadalcanal and over New Guinea . It should be kept in mind that during the period under review Zeros flying from land bases over Guadalcanal almost always entered combat with their external fuel tanks attached. Zeros in combat over New Guinea generally flew without such tanks or dropped them before combat. Without the tank the Zero would have been somewhat faster than flying with the tank attached.
A report summarizing the combat performance of the P-400 and F4F-4 against the Zero over Guadalcanal in late September 1942 stated: “At all altitudes under 10,000 feet the P-400's can pull away from the Zero (P-400 speed about 360 m.p.h. F4F-4 about 40 m.p.h. slower). Zeros are faster than the F4F-4's at all altitudes and more maneuverable…” (Performance).
In a report based on questioning forty fighter pilots of VMF-121, 212 and 251 and VF-71 concerning combats in October 1942 the discussion of comparative performance was brief: “A Zero is faster, more maneuverable, and has a higher rate of climb than our F4F-4s” (Observations).
In an after action interview given in November 1942 Major John Smith, commander of VMF-223 at Guadalcanal , said little about the Zero's performance until asked a direct question and then replied: “They had much more performance than we had. I think they did because we just couldn't stay with them at all, and dog fight at any altitude.”
The F4F-4s of VF-5 commanded by Lt. Commander LeRoy Simpler flew against Zeros from a carrier in August 1942 and were land based on Guadalcanal during September and October 1942. Upon returning to the U.S. Simpler was apprised of the test report that said an F4F-4 was equal in speed to a Zero at low level. His comment was that the report was “flat wrong.”
The reports above are all measured pronouncements by command authorities after careful study or related by experienced combat leaders. In none of the comments in the reports cited above is there any hint that the F4F-4 could equal the Zero in speed even at low level. In fact the contrary is expressly noted. This is despite the fact that the Zeros were handicapped by an external fuel tank. The P-400's speed advantage below 10,000 feet was also enhanced for the same reason.
Airacobras clashed with the Zero on April 30, 1942 in a low level action near Lae , New Guinea . From May to August 1942 combats between Airacobras and Zeros took place on a regular basis over New Guinea . After the first few combats Lt. Col. Boyd D. Wagner wrote a report on the early actions. After commenting that the Zero outperformed the P-39 markedly in maneuverability and climb, Wagner commented on the relative speeds of the aircraft at low altitudes. According to Wagner: “…the Zero was able to keep up with the P-39 to an indicated 290 mph. At 325 indicated just above the water, the P-39 pulled slowly out of range.” Wagner also commented that the P-39's performance above 18,000 feet was very poor.
In later actions combat reports sometimes offer helpful insights into the relative performance of the two aircraft. Lt. Paul G. Brown chased a Zero at 12,000 feet. “He nearly stayed away from me at 350 mph” (Brown). In a low level action: “I indicated 320 mph straight and level at 1,000 feet. Zero kept me in range” (Royal). In another action on the same day Zeros encountered P-39s and P-400s at 21,000 feet. “Zeros stayed with the Airacobras. I dived 12,000 feet indicating 450 miles per hour and Zero stayed with me and followed me to ground level firing. Lt. Martin pulled him off me” (Price). “4 Zeros were over Kokoda and attacked us on the way home. We were barely able to out speed them at 10,000 feet. We were indicating about 350 mph in a very slight dive. Their probable speed 340 mph” (Egenes).
From the Japanese side also comes confirmation that the Zero could hold its own with a P-39 in low-level speed. Sakai relates that on July 22, 1942 he chased a P-39 low over the sea and the P-39 was unable to pull away from him (Sakai, p. 137). The Airacobra was eventually forced to turn in order to take up a course to its base. In the ensuing dogfight Sakai shot the aircraft down. It was probably a P-400 of the 35 th Fighter Group.
This compilation of reports indicates the Zero was either equal to or close to the P-39 in speed at the altitudes of the various encounters. The P-39 was in turn up to 40 m.p.h. faster than the F4F-4 according to reports from the South Pacific Theater. There the Zero was found to be consistently faster than the F4F-4. There is a disconnect between the San Diego test results and multiple reports from the combat zone.
CONCLUSION
The field data reviewed by this study indicate that Zeros operated by the Japanese performed relatively better against the Wildcat and Airacobra than did the Zero tested at San Diego. If the comparative performance of the San Diego Zero understated the performance of a typical Japanese operated Zero, this strongly indicates the quantitative performance was also understated. This tends to verify the conclusions reached in the section reviewing U.S. test results. The reasons for this seem obvious. The San Diego Zero was in less than perfect aerodynamic condition and was not operated at its optimum engine capacity or with automatic mixture control engaged. The figures cited in Summary No. 85 and repeated by Mikesh and Reardon are inaccurate and too low to represent the true performance of the Zero in Japanese operations.
The author has been unable to establish the basis for the performance figures higher than the San Diego test results (332-336 m.p.h.) but lower than Sakai's (sources 5-7 in the section Conflicting Data). They are close to the first test results obtained at San Diego (335 m.p.h.) but those results were not deemed reliable. Absent the basis for these figures nor knowing the conditions that yielded them they are difficult to assess.
Sakai distinguished between normal full power speed (316 m.p.h.) and over boost (345 m.p.h.). His normal full speed is exactly the same as the Zero's maximum speed given in the captured Japanese manual. The San Diego test report, while revealing that the San Diego Zero was not tested at over boost, does confirm Sakai's assertion that such a rating was available. Sakai has credibility that is primarily based on his personal familiarity with the Zero 21 aircraft. These additional factors only bolster his credibility.
The evidence assembled in this report strongly indicates that Sakai's version of the Zero's maximum speed (345 m.p.h.) is highly credible and probably the correct one. Additional support for this conclusion is found in an intelligence document issued in 1944: “Performance data given for the ZEKE Mk. 1 [Allied code name for the Zero 21] was obtained in actual flight tests. Although emergency speed obtained in tests was 328 m.p.h., calculations indicate a maximum speed of about 345 m.p.h. as possible for a short period of time” (Intelligence Summary No. 44-11).
SOURCES
++Wartime reports:
“Performance and Characteristics Trials, Japanese Fighter” Technical Aviation Brief #3, Aviation Intelligence Branch, Navy Department (4 Nov. 42) (extract)
“Flight Characteristics of the Japanese Zero Fighter Zeke” Info rmational Intelligence Summary No. 85, Intelligence Service, U.S.A.A.F., Dec. 42 (rev. Mar. 43)
Memorandum of Oct. 19, 1942, Bureau of Aeronautics, Navy Department to War Department, “Preliminary Zero Data, 10 Oct. 42 (revised)”
Captured Document (Zero Flight Manual), Joint Intelligence Center-Pacific Ocean Area Item No. 5981, Kwajalein, received 19 Feb. 1944
“Zero Test - Mitsubishi Type O Evaluation, Feb. 1943” HQ, 23 rd Fighter Group, 6 Feb. 1943 (“Holloway”)
“Observations of Marine Fighter Pilots at Guadalcanal October 16 to October 31, 1942” (Bauer), United States Pacific Fleet, South Pacific Force, Naval Air Combat Intelligence (extract) (“Observations”)
“Performance of P-400 and F4F-4 in Guadalcanal Area” (Commander, Aircraft, South Pacific Force, 28 Sep 42) (“Performance”)
Interview, Major John Smith (Navy BuAero Nov 42)
Interview, Lt. Cdr. LeRoy Simpler (Navy BuAero Feb 43)
“Report on first action against Japanese by P-39 type airplane” (B.D. Wagner May 42)
Combat Reports (RAAF Form A.108A) for Lt. P.G. Brown, 36 FS (27 May 42); Lt. F. Royal, 39 FS (4 Jul 42); Lt. J.C. Price, 39 FS (4 Jul 42); and, Capt. E. L. Egenes, 40 FS (6 Jul 42) (cited by pilot's last name)
Info rmational Intelligence Summary No. 44-11, Mar 1944, Assistant Chief of Air Staff (Intelligence)
++Books and other sources (generally cited by author's name):
Baugher “Grumman F4F Wildcat” at www.csd.uwo***/f4f.html
Caiden, Zero Fighter, Ballentine (NY 1969)
Dial, “The Bell P-39 Airacobra” Aircraft In Profile vol. 7, Doubleday (NY 1970)
Francillion, “The Mitsubishi A6M2 Zero-Sen” Aircraft in Profile vol. 6, Doubleday (NY 1969)
General View of Japanese Military Aircraft in the Pacific War, compiled by the staff of “Airview” Kanto-sha (Tokyo 1956)
Green, Warplanes of the Second World War, Fighters vol. 3, Doubleday (NY 1961)
Mikesh, Zero, Motorbooks International (Osceola, WI 1994)
Reardon, Cracking the Zero Mystery, Stackpole (Harrisburg PA 1990)
Sakai et al, Samurai, Ballentine (NY 1958)
Taylor, Combat Aircraft of the World, Putnam (NY 1969)
more details(note the FM2 was faster):
http://www.vectorsite.net/avwcat.html
[3] WILDCAT VARIANTS: F4F-4 / MARTLET IV / FM-1 / FM-2
* The folding wing used on the Martlet II had been in the works since March 1940, when the US Navy awarded Grumman a contract to modify the last production F4F-3 with folding wings. Designing the wings so they folded straight up would have been relatively straightforward, but it made demands on the height of carrier hanger decks, and so Grumman came up with an ingenious scheme in which the wings were folded back along the fuselage. The "span" of the folded wings was only 4.37 meters (14 feet 4 inches).
The modified Wildcat, designated the "XF4F-4", performed its first flight on 14 April 1941, and was handed over to the Navy in May. It proved overweight, partly because it was fitted with a relatively cumbersome hydraulic wing-folding scheme. Grumman proposed a manual wing-folding scheme to cut weight and the Navy authorized production of the variant with this feature as the "F4F-4", reaching reaching line service after the Battle of the Coral Sea in May 1942.
The wing-folding mechanism was actuated by a crank inserted into a socket and turned by the deck crew team chief, with the rest of the team helping the wings along to folded position. Once folded, struts were attached between the wingtips and the tailplane to keep the wings in place. The F4F-4 also featured improvements as dictated by British combat experience, such as more armor and self-sealing tanks.
As per British requirements, it was fitted with six 12.7 millimeter Browning machine guns in the wings. Somewhat surprisingly the increased armament was not popular with US Navy and Marine fliers, since the ammunition load was only 240 rounds per gun, resulting in a total ammunition load that was 360 rounds less than that of the F4F-3, which many felt was a very bad bargain. The two outboard guns could be fired separately from the four inboard guns, and many pilots would only use the four inboard guns, retaining the outboard guns as an emergency reserve.
Other changes included a modified pitot tube, moved from the leading edge of the wing to an L-style mount under the wing, and a simplified windscreen that eliminated a brace. The cowling was much like that of late production F4F-3s, with the eight rear cowling flaps, but an airscoop for the carburetor intake was mounted on the upper lip of the cowling.
Once in service, some ingenious mechanics improvised a mount on the centerline for a 159 liter (45 US gallon) external tank; a Grumman engineer named Carl Anderson came up with a better scheme, in which a 220 liter (58 US gallon) external tank was carried inboard on each wing on a somewhat cluttered bracket arrangement. The external tank scheme raised the weight of the aircraft, but the stretched range made it worthwhile. Anderson's scheme was incorporated into Wildcat production, and upgrade kits were provided for Wildcats already in service.
The USN obtained 1,169 F4F-4s. The FAA obtained 220 "Martlet IVs" that were based on the F4F-4 but had substantial differences, most particularly the fit of a Wright R-1820-40B Cyclone in a distinctly more rounded and compact cowling with a single double-wide flap on each side of the rear and no lip intake. These machines were also referred to as "F4F-4Bs" for contractual purposes. At least one Martlet IV was modified by Blackburn Aircraft with six launch rails for "60 pounder" rockets, but the fit was not adopted operationally, possibly because the cluttered launch rails cut into performance too much.
GRUMMAN F4F-4 WILDCAT:
_____________________ _________________ _______________________
spec metric english
_____________________ _________________ _______________________
wingspan 11.58 meters 38 feet
wing area 24.15 sq_meters 260 sq_feet
length 8.76 meters 28 feet 9 inches
height 2.81 meters 28 feet 9 inches
empty weight 2,610 kilograms 5,755 pounds
max loaded weight 3,610 kilograms 7,950 pounds
maximum speed 510 KPH 320 MPH / 280 KT
service ceiling 12,000 meters 39,400 feet
range 1,240 kilometers 770 MI / 670 NMI
_____________________ _________________ _______________________
* The Wildcat was so important to the Allied war effort that General Motors (GM) was enlisted as a second-source. The war had idled five of GM's plants on the East Coast and they were converted to aircraft production as the "Eastern Aircraft Division".
A massive order for Wildcats placed with Eastern Aircraft on 18 April 1942. The GM-built Wildcat was designated the "FM-1", and was similar to the F4F-2 but went back to the older armament configuration of four machine guns instead of six and a larger ammunition supply. Grumman hadn't really wanted the six-gun fit on the F4F-4 in the first place, but compatibility with British requirements had forced the company to go along. With new Wildcat production lines opening up, compatibility was no longer an issue and so the old four-gun armament was reinstated.
The first FM-1 flew on 31 August 1942. 838 were supplied to the USN and 312 were supplied to the British. The Fleet Air Arm originally gave them the designation of "Martlet V", but in January 1944, realizing that maintaining a different name led to various small but obnoxious confusions, decided to adopt the American names for US-supplied aircraft and redesignated them as the "Wildcat V". The British objections to the four-gun armament were dropped, though it is unclear if this was because the FAA had also decided that six-gun armament was a bad idea or if the service was simply taking what it was offered.
* As is typical with combat aircraft development, refinements of the Wildcat added weight, with its inevitable penalty on performance. To compensate, Grumman decided to fit the Wildcat with the Wright XR-1820-56 Cyclone radial engine with 1,010 kW (1,350 HP) and substantially reduced weight, driving an uncuffed Hamilton Standard propeller. The double exhaust stubs found on the bottom of the cowling on every earlier Wildcat were replaced by jet-style exhaust ports to provide incremental additional propulsion thrust; there were two ports on the bottom and one port on each side of the cowling. This prototype, designated the "XF4F-8", also had a lighter airframe.
Initial flight of the XF4F-8 was on 8 November 1942. The torque of the bigger engine affected handling, so a second prototype was built with a tailfin increased in height by 22 centimeter (8.5 inches). Both prototypes were initially fitted with double slotted flaps, but the old single flap proved more effective and they were refitted with it.
The changes proved satisfactory, and so the type went into production at GM as the "FM-2" in mid-1943, when Grumman stopped building Wildcats. The FM-2 was fitted with a production R-1820-56W engine featuring water-methanol power boost and driving an uncuffed Curtiss Electric propeller; a gross weight of 3,600 kilograms (7,950 pounds); and a top speed of 535 KPH (330 MPH). The FM-2 wasn't much faster than its predecessors, but it had a much superior rate of climb and a higher ceiling, though since it used a single-stage supercharger its performance degraded seriously at high altitudes. It was also more agile and had longer range; pilots generally regarded as a fairly hot little aircraft. Other changes included elimination of the useless belly windows, and fit of a straight-up radio mast, instead of a forward-canted radio mast as fitted to earlier production Wildcat variants. The tall tail, lack of belly windows, and vertical radio mast made the FM-2 the easiest of all Wildcat variants to recognize.
The FM-2 became the most heavily produced Wildcat variant, with 4,407 going to the US Navy, plus 370 to the FAA as the "Wildcat VI". The total of FM-2s was actually greater than the total production of all other Wildcat variants combined: ironically, most Wildcats were not built by Grumman. The last 1,400 FM-2s were fitted with three "zero length" launch stubs for High Velocity Air Rockets (HVARs), allowing the FM-2 to carry six HVARs. The HVARs were unguided but could be targeted with relative accuracy using the gunsight and tracer fire. The 7.62 centimeter (5 inch) HVARs gave the FM-2 a good punch in the close-support role and for attacks on submarines and other shipping.
< Message edited by m10bob -- 6/14/2006 5:15:45 AM >
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