Grumman F4F and FM Wildcat details

Grumman F4F and FM Wildcat details

Wildcat landing gear

The Wildcat landing gear was the same for all models. The above photos are of an FM-1, FM-2 and F4F-4. The inside of the gear well is light gray, the gear itself is also light gray above the pivot point of the "trapeze". The portion below that is a heat resistant flat black, this is due to that portion's exposure to engine exhaust when the landing gear is lowered. (CB)

The wheel well as seen on the O'Hare airport wildcat. The first photo is looking aft and showing bulkhead forward of the cockpit. The "bicycle chain" that raises and lowers the landing gear is visible against that bulkhead. The second photo is looking forward and the supercharger intercoolers are prominent inside the opening. The intercooler is tilted outboard at the top and the upper edge protrudes from the fuselage creating the need for the "blister" on the outside. The red box visible inside the wheel well is storage for the star cartridges employed with the Coffman starter. Often referred to as a "shotgun starter" the starter was driven by expanding gas from a cartridge detonated inside achamber. For a good description follow the link to Wikipedia. (CB)

The two tail wheel photos on the left show the hard rubber tire usually associated with carrier operations and used on the F4F-3 and F4F-4. The one to the right is on an FM-2. There was also a pneumatic tire for use in land operations. (CB)

Non folding wing

The F4F-3 Wildcats, Martlet I and Martlet III all lacked folding wings and were armed with four .50 machine guns.

Wing fold

The wing folds were common to all models with this feature (F4F-4, FM-1 & -2, Martlet II, IV and Wildcats V and VI). The crank that is visible in several of the photos was accessed via a panel that opened on the underside of the inner wing stub. This was used to disengage the locking pin that held the wing in the extended position. Once the wing was unlocked it pivoted rearward. The wing is so well balanced that one person can fold, or extend it. The red "flag" visible in some photos is an indicator that the wing is not locked. When the wing folded back a stowage bar was used to keep it in position. This bar ran from the forward wing tip to the leading edge of the horizontal stabilizer. (CB)

Cowls and props

The Wildcat had two basic cowl shapes, the San Diego Air & Space Museum and the NASM's FM-1 illustrates the nose shape common to the Twin Wasp powered Wildcats while the FM-2 represents the Wright Cyclone powered versions. The NASM's FM-1 was missing the cowl ring when it was restored for display. The USMC loaned them an F4F-3 cowl ring that had been part of a Wake Island Memorial, that cowl ring was from one of the later F4F-3s that did not have the intake on the top of the cowl lip. While a good restoration overall, it does not quite represent an F4F-4 or FM-1, but does represent the shape. It is similar to a Martlet II. The underside photo shows the exhaust arrangement for F4F-3 and F4F-4 Wildcats. (CB)

The propeller fitted to the SDASM's and O'Hare examples (first two photos) illustrate the original cuffed Curtiss Electric propeller and hub as fitted on the F4F-3, F4F-4, FM-1 and Martlet III. A few FM-2s were also produced with the Curtiss Electric, but utilized wide chord blades. The third and fourth photos show the un-cuffed Hamilton Standard propeller as used on the Martlet I, Martlet IVs and some FM-2s. The final two show the un-cuffed Curtiss Electric as fitted to the Martlet IIs and some FM-2s. (CB)

There are three different intake arrangements on the F4F/FM series of Wildcats. The first type was used on early and final production F4F-3s as well as the F4F-4. This type had three intakes; one on the top of the cowl and two inside the lip of the cowl at approximately the 4 and 8 o'clock position. The upper one was for the carburetor intake, while the other two were for intercooler air. (CB) The second type moved the carburetor intake inside the top of the lip. This was purportedly due to issues with the effectiveness of the intake. In any case, the intake on top was restored in the F4F-3 and used for the entire F4F-4 and FM-1 production runs. (CB) The third type was the version found on the FM-2, where there were four intakes at approximately the 4,5 7 and 8 o'clock positions. The two lower ones were to provide cool air to the oil cooler and the two upper ones were carburetor intakes. (CB)

Gun Arrangements

The pictures in the top row show the four gun arrangement of the F4F-3, while the first photo on the lower row shows the six gun arrangement for the F4F-4 and Martlet II/IV. To the right is for the four gun arrangement on the FM-1, FM-2 and all four gun Wildcat/Martlet aircraft with non folding wings, with the exception of the Martlet I having its own unique layout.

A few parts...

The pitot tube on the F4F-3 was a straight tube mounted in the port wing. When folding wings were introduced on the Wildcat the pitot tube would have struck the ground ,so the curved example was introduced to protect the head from damage. (CB)

The windscreen and canopy were pretty much unchanged through out the production of the Wildcat, though some Martlets had additional framing in the windscreen. The Mark 8 gun sight was carried through much of the Wildcat's service life. The FM-1 tail shows the shorter tail used on all versions except the FM-2 (and XF4F-8) and the shot on the right is of the taller FM-2 tail. (CB)

    Left: The fairing for the oil coolers on most Wildcat/Martlet airplanes, one under each wing. With the FM-2 the oil cooler was behind the engine and cooling air was ducted through the cowling. (CB)
    Middle: The hook under the keel, below and in front of the wheel, is the attachment point for the catapult bridle. When launching from aboard ship the bridle which had a loop at each end would be attached on one end to the catapult shuttle and the other end would slide over this hook. When the catapult shuttle reached the end of its run the hook would slip from the loop as the aircraft was slung into the air. (CB)
    Right: An illustration of the arrestor hook in the extended position. (CB)
    Far right: The door covering the battery/baggage compartment. Various items such as tool would be stored there. The jury struts to hold the wings in the folded position on later Wildcats were stored in this compartment. (CB)

These shots give a good idea of the appearance of the fabric covered control surfaces and can be used for comparisons to various model kits. (CB)

Pratt & Whitney R-1830 Twin Wasp

The R-1830 used in the F4F was rated at 1,200 hp and was the engine most associated with the Wildcat. Used in the F4F-3, -3A, -4, FM-1, Martlet II, III and the Wildcat V the Twin Wasp was a very reliable engine. It also powered other well known aircraft like the C-47 (and R4D) and the B-24 and is considered to be the most produced aircraft engine in history, with 173,618 produced. Pratt & Whitney has always been known for producing dependable engines and in the days of recipes there was a saying: "If you want to be able to fly fast for a short time you want a Wright, but if you want to be able to fly for a long time use a P&W!" This example, an R-1830-92, is on display at the Smithsonian's National Air and Space Museum on the Mall in Washington, D.C. While most likely a civilian engine (probably from a DC-3), it does provide reference of the appearance for this great engine. (CB)

An R-1830-90C on display at the National Museum of the United States Air Force. This model is very similar to the ones most commonly used to power the F4F-3, F4F-4 and FM-1 Wildcat. (CB)

Some specs:

                                                                                                 SPECIFICATIONS
                                                                                                 Model: R-1830-86
                                                                                                 Type: 14-cylinder, air-cooled, twin row radial
                                                                                                 Displacement: 1830 cu.in.
                                                                                                 Max. RPM: 2,400 (2,700 Military Power)
                                                                                                 Max. HP: 1,200
                                                                                                 Weight: 1,467 lbs.

The P&W powered Wildcats had two exhausts under the forward fuselage. The third port between the two engine exhaust was to dump waste air from the intercoolers. On the F4F-3A which was only equipped with a single stage supercharger that exhaust was unnecessary.

Wright R-1820 Cyclone

The Wright Cyclone was another excellent engine, powering the FM-2, Martlet I, IV (F4F-4B) and of course the Wildcat VI. With this engine the rate of climb for the FM-2 Wildcat improved to approximately 3.200 fpm. This engine also provided better takeoff performance making the FM-2 better suited for use from the small deck of CVEs. Some of the final variants of the R-1820 could produce over 1,500 hp. This engine was also widely used powering such aircraft as the B-17, R4D-8 (C-117D) and the S2F (S-2) Tracker. The first photo shows an R-1820-97 that powered the B-17 and is on display at the 390th BW Memorial Museum located at the Pima Air Museum. The second and third photos show an R-1820-103A on display at the War Eagles Museum. (CB)

Some more specs:

                                                                                                 SPECIFICATIONS
                                                                                                 Model: R-1820-56 and -56W
                                                                                                 Type: 9-cylinder, air-cooled, single row radial
                                                                                                 Displacement: 1823 cu.in.
                                                                                                 Max. RPM: 2,600 (2,700 for -56A and -56WA)
                                                                                                 Max. HP: 1,350
                                                                                                 Weight: 1,329 lbs

R-1820 Power Plant Chart applicable to the
Eastern FM-2 Wildcat

The FM-2 had an exhaust on each side of the fuselage above the wing and two under the forward fuselage. Those two are visible in the second photo forward of the landing gear. The catapult hook used on all versions of the Wildcat is also apparent in that photograph. (CB)

(While the two charts above are not exactly "apples to apples", they do provide some interesting data on both the Twin Wasp and the Cyclone.)

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Created 04-08-04
Modified 10-12-19
Clifford Bossie