Grumman F7F Tigercat

by Jack McKillop

The Grumman Aircraft Engineering Corporation

See Grumman F3F.

Description

The F7F was a twin-engine, single- or two-seat, all-metal, shoulder-wing monoplane day or night fighter. The outer wings folded upwards for storage. The landing gear was a retractable tricycle type with the main wheels retracted backwards into the engine nacelles and the nose wheel retracting backwards into the nose.

Production History

Grumman had a history in building twin-engine fighter aircraft for the military. The first was the XF5F-1 (q.v.) which first flew in April 1940. The Navy did not place an order for this aircraft but it served as a development prototype for the F7F. The second aircraft was the U.S. Army Air Corps’ (USAAC) XP-50. This aircraft featured a tricycle landing gear but it was destroyed after completing 20 hours of flying when a turbosupercharger exploded in flight.

A successor to the XP-50 was the USAAC’s XP-65 which was ordered in May 1941. The idea was to build an aircraft that could be used by both the Army and Navy but the USAAC had the  Lockheed P-38 Lightnings in the inventory and the Army cancelled their contract to enable Grumman to concentrate on the naval version.

A number of “firsts” can be attributed to the F7F. It was the Navy’s first twin-engine fighter to go into production, the first with a tricycle landing gear and the first fighter that had the capability to drop a torpedo. From the beginning, Grumman had recommended that the F7F be built as a night fighter and it was agreed that production aircraft would be equipped with a Sperry AN/APS-6 X-band search and intercept radar system in the nose. Thus, the F7F became the first single-seat aircraft to be equipped with an internally-mounted radar system.

XF7F-1: On 30 June 1941, the U.S. Navy signed a contract for two XF6F-1 Hellcat prototypes. On the same day, they signed a second contract for two XF7F-1 Tigercat prototypes. The F7F was intended to be a twin-engine carrier-based fighter that would operate from the large aircraft carriers of the Midway Class.

The first prototype was powered by two 2,000 horsepower Pratt & Whitney R-2800-27 18-cylinder, twin-row, air-cooled radial engines driving a three bladed propeller fitted with a large spinner. The second prototype was powered by two 2,100 horsepower R-2800-22 engines. These aircraft were built to be equipped with the radar in the nose and armed with four 0.50-caliber (12.7-mm) machine guns and four 20-mm cannons but neither the guns or radar were initially installed.
The first official flight by the first prototype occurred on 2 November 1943; the second prototype was first flown on 2 February 1944.

The F7F flew faster than the F4U Corsair and F6F Hellcat at low altitudes and it was maneuverable however, it had marginal spin characteristics and it was directionally unstable. A dorsal fin extension was fitted on the first prototype to correct this latter problem.

The first XF7F-1 was damaged on 1 May 1944 and it was struck from the inventory at the end of August. The second prototype was stricken from the inventory on 30 November 1946.

F7F-1N: The Navy ordered 500 of these night fighters but only 35 were produced. The biggest difference between these aircraft and the prototypes was the engines; this aircraft was powered by 2,100-horsepower R-2800-22W engines with water injection. The propeller spinners were eliminated and the windshield was a three-piece construction instead of the single-piece of the XF7F-1. These aircraft were equipped with the AN/APS-6 intercept radar and four 0.50-caliber (12.7-mm) machine guns in the nose with 400 rounds per gun and four 20-mm cannons with 200 rounds per gun mounted in the wings and they had the capability of carrying a 150- or 300-U.S.-gallon (125-or 250-Imperial-gallon or 568-or-1,136-liter) drop tank on the belly of the aircraft.

The F7F-1N suffered from the same problems of the prototype, i.e., poor directional stability characteristics and the Navy asked Grumman to design a larger vertical fin to overcome this problem.

All 35 of these aircraft were equipped with radar and should have been classified as F7F-1N aircraft but both the F7F-1 and F7F-1N designations are found in Navy and Grumman documentation to identify these aircraft.

XF7F-2: The F7F-1N was a single-seat night fighter but in January 1944, the Navy asked Grumman to design a two-seat version allowing a radar operator to operate the radar equipment. The third production F7F-1N was converted to a two-seat fighter by reducing the size of a fuel tank located behind the pilot and installing a seat and the necessary radar instruments for the observer. This reduced the internal fuel tankage from 426-to-375-U.S.-gallons (355-to-312-Imperial gallons or 1,613-to-1,420-liters).

F7F-2: There was confusion initially as to whether the 65 F7F-2s delivered were F7F-2s or F7F-2Ns because like the F7F-1N, the two terms were used indiscriminately. Eventually, the F2F-2 designation was assigned to aircraft modified as a single-seat fighter by eliminating the radar observer’s position and inserting an 80-U.S.-gallon (67-Imperial-gallon or 303-liter) fuel tank covered by a metal fairing in the position behind the pilot.

F7F-2D: This was a drone director version of the F7F-2N. In 1946, a few F7F-2Ns were modified by removing all of the radar equipment in the rear cockpit normally occupied by the radar operator. All available F7F-2Ns were modified to this configuration in 1948. All armament was also removed and an automatic direction finding antenna was installed above the nose.

F7F-2N: Sixty five aircraft were delivered between 31 October 1944 and 8 August 1945. They were essentially F7F-1Ns with a second seat for the radar operator covered by a one-piece canopy. Armament was the same but launchers for eight 5-inch (12.7-centimeter) High Velocity Aircraft Rockets (HVARs) were mounted under the wings, four to a wing.

F7F-3: The 189 F7F-3s were single-seat fighter-bombers with a larger vertical fin and powered by 2,100-horsepower Pratt & Whitney R-2800-34W 18-cylinder, twin-row, air-cooled radial engines with water injection. The racks for HVARs under the wings were replaced with updated racks that could be used with HVARs or 250-pound (113-kilogram) bombs. Racks were also installed under the fuselage and between the fuselage and engine nacelles. The latter racks could carry a 1,000-pound (454-kilogram) bomb while the rack under the fuselage could carry a 2,000-pound (907-kilogram) bomb or a Mk. 13 torpedo. These aircraft were delivered between 14 March 1945 and 20 June 1946.

F7F-3K: At least one F7F-3 was converted to a radio control drone in 1946.

F7F-3N: Sixty two-seat night fighters equipped with the U.S. Army Air Forces’ X-band SCR-720 intercept radar system which had a greater range than the AN/APS-6 system. Because of the radar equipment’s size, the four 0.50-caliber (12.7 mm) machine guns were removed from the nose.

F7F-3P: At least 61 F3F-3s converted in 1945 to photographic reconnaissance aircraft. The camera were located on both sides of the rear fuselage; the pilot would use a periscopic sight to take pictures. Most of these aircraft had an automatic direction finding antenna mounted on the upper fuselage.

XF7F-4N: One F7F-3 modified into a two-seat night fighter in 1945. The aircraft was equipped with an AN/APS-19 X-band search and intercept radar mounted in the nose. This radar set that provided search, intercept, gun-aiming, beacon, and Identification Friend or Foe (IFF) data.

F7F-4N: Twelve two-seat night fighters with enlarged tail surfaces, AN/APS-19 radar and modified landing gear delivered between 17 September and 7 November 1946. Armament was four 20 mm cannons in the wings.

Operational History

Although this aircraft was intended to be a Navy carrier-based night fighter, it never served on an aircraft carrier and the majority of them served with the U.S. Marine Corps.

The F7F was a heavy fighter requiring higher capacity arrester gear and special barriers for the tricycle landing gear which were being installed on newer Essex Class carriers. However, an F7F-1N completed initial carrier qualification tests aboard USS Shangri-La (CV-38) on 15 November 1944.

The F7F went to the Marines for two reasons: (1) the first Midway Class large aircraft carrier, USS Midway (CVB-41), was not commissioned until 10 September 1945 and (2) the Navy still had reservations about the aircraft’s carrier compatibility. Plans were developed to equip ten Marine night fighter squadrons and the Navy would take over a equal number of Corsairs.

In January 1945, Marine Night Fighter Squadron Five Hundred Thirty One [VMF(N)-531] began training in F7F-2Ns at Marine Corps Air Station (MCAS) Eagle Mountain Lake, Texas, located about 15-miles (24-kilometers) northwest of Fort Worth, Texas.

VMF(N)-531 completed training and began moving to Okinawa in June 1945. In July, they sailed in the escort aircraft carrier USS Attu (CVE-102) for Guam. While aboard, the two atom bombs were dropped on Japan and the Japanese proclaimed their surrender to the Allies on 15 August. VMF(N)-531 was en route from Guam to Chimu Airfield, Okinawa (26°27'34"N, 127°55'04"E) via Iwo Jima arriving on 18 August. The squadron’s 12 F7F-2Ns were absorbed by VMF(N)-533 and they began flying night combat air patrols. In October 1945, VMF(N)-533 moved to China where they remained until January 1947.

During the Korean War, VMF(N)-542 with F7F-3Ns, was ordered to Kimpo Airfield in September 1950 and flew close air support, air interdiction, and reconnaissance flights. The squadron returned to the U.S. in March 1951 and the F7F-3Ns were transferred to VMF(N)-513 which were flying out of Pusan West Air Base (K-1) and providing the sole night fighter air defense and interdiction support to all UN forces. They flew their last combat mission in April 1952 and during the summer of 1952, VMF(N)-513 received the F3D Skyknight, the squadron's first jet aircraft.

With the Navy, Night Fighting Squadron Fifty Two [VF(N)-52] was established on 6 January 1945, equipped with F7F-2Ns and disestablished on 25 May 1945. Two Night Composite Squadrons (VCNs) flew F7Fs between 1946 and 1950. The F7F also was assigned to two Air Development Squadrons and two Utility Squadrons. The last F7Fs in squadron service were F7F-4s assigned to Navy Photographic Squadron Sixty Two (VJ-62) based at Naval Auxiliary Air Station (NAAS) Sanford, Maine, on 31 March 1954.          

Survivors On Display In The U.S.

ARIZONA: The Pima Air & Space Museum in Tucson has an F7F-3 on display.

CALIFORNIA
   Chino: The Planes of Fame Air Museum has an F7F-3N on display.
   Palm Springs: The Palm Springs Air Museum has an F7F-3 on display.

FLORIDA
   Pensacola: The National Naval Aviation Museum (formerly National Museum of Naval Aviation) has an F7F-3 on display.
   Polk City: The Fantasy of Flight Museum has an F7F-3 that may be seen by serious researchers with prior permission.
 
MICHIGAN: The Air Zoo in Kalamazoo has an F7F-3 on display. 

BuAer Numbers

03549/03550.....XF7F-1
80259/80260.....F7F-1
80261................XF7F-2
80262/80293.....F7F-1  Some were painted with F7F-1N designations.
80294/80358.....F7F-2N
80359/80548.....F7F-3
80411................F7F-3 modified in 1946 to F7F-3K
80412/80547.....F7F-3
80548................F7F-3 converted to XF7F-4N
80549/80608.....F7F-3N
80609/80620.....F7F-4N       

Specifications

Wingspan: 51-feet 6-inches (15.60 meters)
Wing Area: 455-square-feet (42.26-square-meters)
Length
   XF7F-1: 45-feet 6.5-inches (13.86-meters)
   F7F-3N: 45-feet 9.25-inches (14.24-meters)
   F7F-4N: 45-feet 5 inches (13.84-meters)
   All others: 45-feet 4.5-inches (13.81-meters)
Height
   XF7F-1: 13-feet 9-inches (4.19-meters)
   F7F-1 and F7F-2N: 15-feet 2-inches (4.62-meters)
   All others: 16-feet 4-inches (4.97-meters)
Empty Weight
   XF7F-1: 15,274-pounds (6,928-kilograms)
   F7F-1: 15,681-pounds (7,113-kilograms)
   F7F-2N: 16,028-pounds (7,270-kilograms)
   F7F-3: 16,396-pounds (7,437-kilograms)
   F7F-3N: 16,592-pounds (7,526-kilograms)
   F7F-3P: 16, 396-pounds (7,437-kilograms)
   F7F-4N: 16,954-pounds (7,690-kilograms)
Maximum Speed
   XF7F-1: 429 mph (690 km/h)
   F7F-1 and F7F-2N: 445 mph (716 km/h)
   F7F-3: 460 mph (740 km/h)
   F7F-3N: 447 mph (719 km/h)
   F7F-3P: 450 mph (724 km/h)
   F7F-4N: 430 mph (692 km/h)
Service Ceiling
   XF7F-1: 42,200-feet (12,863-meters)
   F7F-1: 36,200-feet (11,034-meters)
   F7F-2N: 39,800-feet (12,131-meters)
   F7F-3: 40,700-feet (12,405-meters)
   F7F-3N: 40,800-feet (12,436-meters)
   F7F-3P: 40,400-feet (12,314-meters)
   F7F-4N: 40,500-feet (12,344-meters)
Range
   XF7F-1: 1,160-miles (1,867-kilometers)
   F7F-1: 1,170-miles (1,883-kilometers)
   F7F-2N: 960-miles (1,448-kilometers)
   F7F-3: 1,200-miles (1,931-kilometers)
   F7F-3N: 960-miles (1,448-kilometers)
   F7F-4N: 810-miles (1,304-kilometers)