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Grumman XTSF & G-66

The Grumman XTSF was a proposed twin-engine torpedo scout aircraft, designed by Grumman for the United States Navy towards the end of World War II.

Based on the design of the Grumman F7F Tigercat fighter but enlarged and with the addition of a bomb bay, the XTSF was deemed too large for carrier operations, and the project was cancelled before any aircraft were built.

Instead, the Navy chose to order the single-engine XTB3F, which became the successful AF Guardian.

In 1944, it was determined that the Grumman XTB2F, then under development for the Navy, would be too large to practically and safely operate from aircraft carriers.

Even the new Midway-class aircraft carriers, known as “battle carriers” (CVB) and the largest aircraft carriers built by any nation to that point, would have difficulty operating the massive aircraft, which was the size of a U.S. Army Air Force medium bomber. 

As a result, in late June 1944, Grumman submitted its G-66 design to the Bureau of Aeronautics (BuAer).

After a review of the design by BuAer during the following month, a revised design was submitted, and on August 17 the existing contract for the XTB2F was modified to instead order two XTSF-1 aircraft, to be based on Grumman’s F7F-2 Tigercat two-seat, twin-engined fighter-bomber, the first prototype intended to be a conversion of a F7F airframe.

A mid-wing, all-metal, cantilever monoplane with two Pratt & Whitney Double Wasp radial engines mounted in streamlined nacelles under the wing, the XTSF-1 was intended to carry two crew members in tandem seats and featured an internal bomb bay and an SCR-720 radar set, the radar later being replaced in the design by an AN/APS-3 or AN/APS-4 set.

A second seat was added for the radar operator.

The outer wing of the XTSF was lengthened by 7.8 feet (2.4 m) compared to that of the F7F-2, while the size of the horizontal stabilizer was increased by 28 inches (71 cm)).

The vertical stabilizer was also enlarged, while the aircraft’s weight increased by almost two thousand pounds (910 kg) over that of the Tigercat.

The wings folded upwards for stowage aboard aircraft carriers, while the undercarriage and arrestor hook were hydraulically operated.

Gun armament was planned to be four .50 calibre (12.7 mm) Browning M2 machine guns, or, alternatively, two 20 mm Hispano cannon, while a bomb bay based on that of the Grumman TBF Avenger was installed in a fuselage stretched by 5.5 inches (14 cm).




46 ft 4 in (14.12 m)


59 ft 4 in (18.08 m)

(Folded span 32 feet (9.8 m))


16 ft (4.9 m)

Wing area

500 sq ft (46 m2)


NACA 23015-23012

Empty weight

17,288 lb (7,842 kg)

Gross weight

26,171 lb (11,871 kg)

Fuel capacity

400 US gallons (1,500 l; 330 imp gal)


2 × Pratt & Whitney R-2800-22W Double Wasp radial engines,

2,400 hp (1,800 kW) each


4-bladed Aeroproducts H-20-156,

13 ft 2 in (4.01 m) diameter


Maximum speed

414 mph (666 km/h, 360 kn) at 18,600 feet (5,700 m)

Stall speed

84 mph (135 km/h, 73 kn)


975 mi (1,569 km, 847 nmi) internal fuel at 172 miles per hour (277 km/h)

Combat range

395 mi (636 km, 343 nmi) radius with two 150 US gallons (570 l; 120 imp gal) drop tanks

Service ceiling

36,500 ft (11,100 m)

Rate of climb

3,920 ft/min (19.9 m/s)

Wing loading

47.9 lb/sq ft (234 kg/m2)





4 x .50-calibre machine guns


Two, 1,000 pounds (450 kg) capacity each


Internal bomb bay

Capacity one Mark 13 torpedo,

One 2,000 pounds (910 kg) bomb


Naval mine,

Or up to 4,000 pounds (1,800 kg) smaller bombs,

Or up to 1,300 pounds (590 kg) depth charges.




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