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Grumman XTSF-1 (G-66)

United States (1945)
Picture of Grumman XTSF-1 (G-66) Twin-Seat, Twin-Engine Carrierborne Torpedo Bomber Proposal

The Grumman XTSF-1 was another contender to replace the war-winning TBF Avenger family - only a mockup was completed.


Detailing the development and operational history of the Grumman XTSF-1 (G-66) Twin-Seat, Twin-Engine Carrierborne Torpedo Bomber Proposal.  Entry last updated on 2/14/2018. Authored by Staff Writer. Content ©www.MilitaryFactory.com

It was long road towards acceptance of a twin-engined aircraft for carrier-based operations by the United States Navy (USN) during World War 2 (1937-1945). This was eventually realized with the adoption of the Grumman F7F "Tigercat" which first-flew on November 2nd, 1943 but the design arrived too late to see combat service in the conflict. Three hundred sixty-four of the type were built but only the late-model F7F-4N was actually certified for carrier deck operations - the rest of the lot were operated from land bases.

During the latter half of the war, the USN was actively searching for a replacement for its war-winning Grumman TBF "Avenger" torpedo bomber. This single-engine, three-crew platform was built in nearly 10,000 examples before the end of its run and went on to be used by various global air services during the war and after it. There were several attempts, such as the XTB2F-1 (detailed elsewhere on this site), that were meant to succeed the classic Navy attacker.

The XTB2F-1 ended up being much too large and heavy for service aboard the Essex- and Midway-class aircraft carriers and was cancelled after a review of the mockup. The service then turned its attention to another possible candidate - this in the form of a modified F7F Tigercat - to which Grumman responded with the "Model G-66" proposal. Use of the existing Tigercat design was intended to speed up development and production while also controlling costs. Grumman responded with a concept in June of 1944 and this form was revised some following a Navy review in July of that year. A development contract was then handed over in August to cover a pair of flyable prototypes under the XTSF-1 designation. By this point, the Navy foresaw a combat aircraft capable of torpedo delivery but also in scouting the vast expanses of the Pacific (so inherent range was equally important). A mock-up became ready for review in October of 1944.

From the base F7F-2 airframe, Grumman engineers reworked the fuselage to accept radar and a bomb bay. The former was installed in an enlarged nose cone which immediately changed the fine lines of the Tigercat for the worse and added nearly six inches to her length. The intended radar fit would have been the AN/APS-3 or AN/APS-4 series models. The existing bomb bay of the TBF was installed into the slim body of the Tigercat which also reworked the fine contouring once present in the original Grumman heavy fighter.
All of the wing surfaces were either enlarged or lengthened for the added control needed in the torpedo bombing role. One of the few qualities of the Tigercat left untouched was its 2 x Pratt & Whitney R-2800-22W "Double Wasp" air-cooled radial piston engines of 2,400 horsepower each. These would be used to drive four-bladed propeller units and held in streamlined nacelles at each wing mainplane, extending beyond both the leading and trailing edges.

Dimensions included a length of 46.3 feet, a wingspan of 59.4 feet and a height of 16 feet. To stow properly on American carriers, the wings were made to fold which reduced the span to 32 feet. Empty weight was estimated at 17,300lb with a gross weight ballooning to nearly 26,200lb. A crew of two would be featured.

Estimated performance had the aircraft reach speeds between 390 and 415 miles-per-hour with a range out to 975 miles on internal fuel alone (with a listed combat radius of 420 miles). Its service ceiling was proposed at 36,500 feet with a rate-of-climb reaching 4,000 to 4,400 feet-per-minute.

The original Tigercat armament was reworked to be just paired 0.50 caliber heavy machine guns found at each inboard wing section. Provision was made to also replace these weapons with single-mounted 20mm autocannons at a future date. The internal bay could hold up to 2,000lb of stores, these being either a single Mark 13 torpedo, a large bomb, a collection of smaller bombs, depth charges or naval mines. There would be two external underwing hardpoints set to carry an additional 1,000lb of ordnance (each).

Just like the earlier XTB2F-1 proposal, the XTSF-1 was also thought to be much too large and heavy for service on the then-current generation of American fleet carriers. This ended all hope for the Tigercat conversion as a torpedo bomber and the XTSF-1 was cancelled as soon as January of 1945. The war ended in August of that year.






Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

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Relative Maximum Speed Rating
Hi: 500mph
Lo: 250mph
    This entry's maximum listed speed (413mph).

    Graph average of 375 miles-per-hour.
Relative Operational Ranges
NYC
 
  LON
LON
 
  PAR
PAR
 
  BER
BER
 
  MOS
MOS
 
  TOK
TOK
 
  SYD
SYD
 
  LAX
LAX
 
  NYC
Graph showcases the Grumman XTSF-1's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era Impact
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Unit Production Comparison
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
0
0


  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.


Altitude Visualization
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National Origin: United States
Service Year: 1945
Classification Type: Twin-Seat, Twin-Engine Carrierborne Torpedo Bomber Proposal
Manufacturer(s): Grumman Aircraft - USA
Production Units: 0
Operational Status: Cancelled
Global Operators:
United States (cancelled)
Measurements and Weights icon
Structural - Crew, Dimensions, and Weights:
Unless otherwise noted the presented statistics below pertain to the Grumman XTSF-1 model. Common measurements, and their respective conversions, are shown when possible.

Operational
CREW


Personnel
2


Dimension
LENGTH


Feet
46.33 ft


Meters
14.12 m


Dimension
WIDTH


Feet
59.38 ft


Meters
18.1 m


Dimension
HEIGHT


Feet
16.08 ft


Meters
4.9 m


Weight
EMPTY


Pounds
17,295 lb


Kilograms
7,845 kg


Weight
LOADED


Pounds
26,235 lb


Kilograms
11,900 kg

Engine icon
Installed Power - Standard Day Performance:
2 x Pratt & Whitney R-2800-22W "Double Wasp" air-cooled radial piston engines developing 2,400 horsepower each and each used to turn four-bladed propeller units.

Performance
SPEED


Miles-per-Hour
413 mph


Kilometers-per-Hour
665 kph


Knots
359 kts


Performance
RANGE


Miles
994 mi


Kilometers
1,600 km


Nautical Miles
864 nm


Performance
CEILING


Feet
36,417 ft


Meters
11,100 m


Miles
6.90 mi


Performance
CLIMB RATE


Feet-per-Minute
4,200 ft/min


Meters-per-Minute
1,280 m/min

Armament - Hardpoints (2):

PROPOSED:
4 x 0.50 caliber heavy machine guns in wing roots (provision had for later upgrading these to 2 x 20mm cannon installations).

OPTIONAL:
Internal bomb bay for up to 2,000lb of stores including torpedos, drop bombs, depth charges and naval mines.

Two external hardpoints to carry an additional 1,000lb of stores each.
Supported Weapon Systems:

Graphical image of an aircraft medium machine gun
Graphical image of an aircraft heavy machine gun
Graphical image of an aircrat automatic cannon
Graphical image of an aircraft aerial torpedo
Graphical image of an aircraft conventional drop bomb munition
Variants: Series Model Variants
• XTSF-1 - Base Series Designation; mock-up work was all that was had on the project before cancellation.