Grumman AF Guardian

AF Guardian
Hunter-Killer team of AF-2W (lower) and AF-2S
Role Anti-submarine aircraft
National origin United States
Manufacturer Grumman
First flight 19 December 1945
Introduction October 1950
Retired 31 August 1955
Status Replaced by S-2 Tracker
Primary user United States Navy
Number built 389

The Grumman AF Guardian was the first purpose-built anti-submarine warfare (ASW) carrier-based aircraft to enter service with the United States Navy.[1] It consisted of two airframes, one for detection gear, the other for weapons. The Guardian remained in service until August 1955, when it was replaced by the twin-engine Grumman S-2 Tracker. The Guardian was the largest single-engine piston-powered carrier aircraft ever to see service.[2]

Contents

Design and development

The original design concept for the aircraft that would become the Guardian, the XTB2F of 1944, was to be a twin-engined aircraft with a 3,600 lb (1,633 kg) warload and a range of 3,700 mi (5,950 km).[3] This was considered to be too large for practical use from an Essex class aircraft carrier, and was canceled in 1945, replaced by a modified Grumman F7F Tigercat, the XTSF-1.[4]

However, this too was considered impractical,[5] and another alternative, the internally-developed Grumman Model G-70, was selected instead, being given the Navy designation XTB3F. This was designed as mixed-power aircraft, with a Pratt & Whitney Double Wasp radial engine in the nose and a Westinghouse 19XB turbojet in the tail.[4] This was found to be unsuitable and the jet engine was removed without ever having been used in flight.[4] The XTB3F-1S carried a crew of two seated side-by-side and an armament of two 20 mm cannon and 4,000 lb (1,814 kg) of bombs, torpedoes and/or rockets, and made its first flight on 19 December 1945.[4]

On 24 December 1945, the Navy changed the role of the aircraft from torpedo-bomber to anti-submarine warfare. All the required equipment could not be fitted into a single aircraft, consequently two variants would be produced, one as a "guppy" (hunter) and another as a "scrapper" (killer). [6] The hunter aircraft would not carry any armament,[2] but instead two additional crew members and a ventral radome for APS-20 search "eyes" (radar) and Electronic Countermeasures (ECM) "ears", consisting of an APR-98 Countermeasures Receiver and AP-70 Bearing Indicator. [7]This aircraft, the XTB3F-1S, first flew in November 1948.[4] The "killer" deleted the cannon of the torpedo bomber, but retained the bomb bay, added a third crewmember, a searchlight, and short-range radar, and (as the XTB3F-2S) first flew in January 1949.[4]

Operational history

Redesignated as AF-2W (TB3F-1S) and AF-2S (TB3F-2S), the Guardian entered fleet service on 27 September 1950 with three aircraft delivered to VS-24,[8]with full service introduction shortly after[9] with VS-25.[10] A total of 193 AF-2S Guardians were built.[9] In 1952, the AF-3S (hunter) was introduced, fitting a magnetic anomaly detector (MAD) for the detection of submerged submarines; 40 of this variant were built.[9] The last Guardian was delivered to the Navy in March 1953,[9] with a total of 389 built.[4]

The Guardian saw service in the maritime patrol role during the Korean War, however it proved unpopular with pilots, being underpowered and heavy on the controls; the aircraft suffered from a severely high accident rate.[4] Shortly after the end of the war, it began to be replaced by the Grumman S2F Tracker,[9] the first purpose-built single airframe ASW airplane to serve the U.S. Navy.[11] The last AF retired from active service on 31 August 1955, [4] but it remained in service with the US Naval Air Reserve until 1957.[4]

Variants

XTB3F-1
Prototypes of two-seat torpedo bomber powered by two 2,300 hp R-2800-46 engines and a Westinghouse turbojet; three built.[4]
XTB3F-1S
Two modified XTB3F-1 prototypes with turbojet removed and ventral radome , later re-designated as XAF-1.[4]
AF-2S
Production variant with 2,400 hp R-2800-48 engines, 193 built.[9]
AF-2W
Hunter variant with search radar in a ventral radome, 153 built.[9]
AF-3S
Hunter/Killer variant similar to AF-2S with retractable MAD boom, 40 built.[9]
Grumman Model G-90
Proposed combined AF-2S/-2W version, cancelled.

Operators

 United States

Survivors and aircraft on display

After disposal by the U.S. Navy five Guardians saw many years service with Aero Union based at Chico California in the forest fire-fighting role, the last being retired in 1978.[12]

On 30 March 1954, after encountering engine trouble while on a rescue mission, pilot Lt. John W. Miller with his two crew, Bill Burris and Walter G. Brown ditched an AF Guardian in the water near Santa Cruz Island. A rescue helicopter picked them up that afternoon but the Grumman AF Guardian remains in 60 ft of water to become a living reef and no efforts have been made since to recover the aircraft.[18]

Specifications (AF-2S Guardian)

Data from United States Navy Aircraft since 1911 [19]

General characteristics

Performance

Armament

See also

Aircraft of comparable role, configuration and era

References

Notes
  1. ^ Kowalski 1991, p. 3.
  2. ^ a b Donald and March 2001, p. 46.
  3. ^ Kowalski 1991, pp. 2–3.
  4. ^ a b c d e f g h i j k l m Goebel, Greg. "Grumman AF Guardian." VectorSite, 2009. Retrieved: 16 January 2011.
  5. ^ Norton 2008, p. 120.
  6. ^ Kowalski 1991, p. 16.
  7. ^ Kowalski 1991, p. 18.
  8. ^ Kowalski 1991, p. 14.
  9. ^ a b c d e f g h Swanborough and Bowers 1990, p. 246.
  10. ^ Wagner 1982, p. 498.
  11. ^ Donald and March 2001, p. 50.
  12. ^ "Aircraft Collection." Pima Air & Space Museum. Retrieved: 16 January 2011.
  13. ^ a b c d Goodall 2005
  14. ^ a b Kowalski 1991, p. 81.
  15. ^ "AF2S Guardian." Arizona Wing Commemorative Air Force. Retrieved: 10 May 2011.
  16. ^ "Aircraft Collection." Pima Air & Space Museum. Retrieved: 16 January 2011.
  17. ^ "AF-2S Aircraft, Bureau Number 123100." National Museum of Naval Aviation. Retrieved: 16 January 2011.
  18. ^ Wilson, Bill. "Diving the Grumman Guardian." California Wreck Divers. Retrieved: 11 May 2011.
  19. ^ Swanborough and Bowers 1976, p. 228.
Bibliography
  • Donald, David and Daniel J. March. Carrier Aviation Air Power Directory. Norwalk, CT: AIRtime Publishing, 2001. ISBN 1-880588-43-9.
  • Goodall, Geoffrey. Warbirds Directory. Victoria, Australia: Victoria Publishing, Fourth Edition 2005.
  • Gunston, Bill. Grumman: Sixty Years of Excellence. New York: Orion Books, 1988. ISBN 0-517-56796-2.
  • Kowalski, Robert J. Grumman AF Guardian. Naval Fighters Series (#20). Simi Valley, CA: Steve Ginter Publishing, 1991, ISBN 0-942612-20-5.
  • Pilot's Manual for Navy Model AF-2S Aircraft, AN 01-85DAB-1. Washington: Secretary of the Air Force and the Bureau of Aeronautics, 4 March 1951; reissued in digital DVD version as Grumman AF-2S Flight Manual, AN 01-85DAB-1, 1951. Richmond Hill, Ontario, Canada: Sicuro Publishing Inc., 2011.
  • Swanborough, Gordon and Peter M. Bowers. United States Navy Aircraft since 1911. London: Putnam, Second edition, 1976. ISBN 0-370-10054-9.
  • Swanborough, Gordon and Peter M. Bowers. United States Navy Aircraft since 1911. London: Putnam, Third edition, 1990. ISBN 978-0870217920.
  • Thruelsen, Richard. The Grumman Story. New York: Praeger Publishers, Inc., 1976. ISBN 0-275-54260-2.
  • Wagner, Ray. American Combat Planes. New York: Doubleday & Company, Third Edition, 1982. ISBN 0-385-13120-8.

External links