Grumman AF Guardian
{{Short description|Anti-submarine aircraft family by Grumman}}
{{Use dmy dates|date=March 2020}}
{{Infobox aircraft
|name= AF Guardian
|image= File:AF-2W AF-2S VS-25.jpg
|caption= Hunter-Killer team of AF-2W (lower) and AF-2S
|type= Anti-submarine warfare aircraft
|national_origin= United States
|manufacturer= Grumman
|designer=
|first_flight= 19 December 1945
|introduction= October 1950
|retired= 31 August 1955
|status=
|primary_user= United States Navy
|more_users=
|produced=
|number_built= 389
|developed_from=
|variants=
}}
The Grumman AF Guardian is the first purpose-built anti-submarine warfare (ASW) carrier-based aircraft to enter service with the United States Navy.Kowalski 1991, p. 3. It consisted of two airframe variants, one for detection gear, the other for weapons. The Guardian remained in service until August 1955, when it was replaced by the twin-engined Grumman S-2 Tracker. The Guardian was the largest single-engine piston-powered carrier aircraft ever to see service.
Design and development
The original design concept for the aircraft that would become the Guardian, the XTB2F of 1944, was for a twin-engined aircraft with a {{cvt|3600|lb|kg}} warload and a range of {{cvt|3700|mi|km}}.Kowalski 1991, pp. 2–3. This was considered to be too large for practical use from an {{Sclass|Essex|aircraft carrier}}, and was cancelled in 1945, replaced by a modified Grumman F7F Tigercat, the XTSF-1.
However, this too was considered impractical,Norton 2008, p. 120. and another alternative, the internally developed Grumman Model G-70, was selected instead, being given the Navy designation XTB3F-1. This was designed as mixed-power aircraft, with a Pratt & Whitney Double Wasp radial engine in the nose and a Westinghouse 19XB (J30) turbojet in the tail. Originally, the Westinghouse engine was to be the new X24C, which was to emerge as the J34. When it became apparent the X24C delivery schedules would not meet the airframe schedule, the 19XB-2B was substituted. This was found to be unsuitable, and the jet engine was removed without ever having been used in flight. The XTB3F-1 carried a crew of two seated side by side and an armament of two 20 mm cannon and {{cvt|4,000|lb|kg}} of bombs, torpedoes, and rockets, and made its first flight on 19 December 1945.
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).Kowalski 1991, p. 16. The hunter aircraft would not carry any armament,Donald and March 2001, p. 46. but instead two additional crew members and a ventral radome for AN/APS-20 search radar and electronic countermeasures (ECM) consisting of an AN/APR-98 countermeasures receiver and AN/AP-70 bearing indicator.Kowalski 1991, p. 18. This aircraft, the XTB3F-1S, first flew in November 1948. 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.
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,Kowalski 1991, p. 14. with full service introduction shortly after with VS-25.Wagner 1982, p. 498. A total of 193 AF-2S Guardians were built. 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. The last Guardian was delivered to the Navy in March 1953, with a total of 389 built.Goebel, Greg. {{usurped|1=[https://web.archive.org/web/20080605225040/http://www.vectorsite.net/avguard.html "Grumman AF Guardian."]}} VectorSite, 2009. Retrieved: 16 January 2011.
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. Shortly after the end of the war, it began to be replaced by the Grumman S2F Tracker, the U.S. Navy first purpose-built ASW airplane to combine the hunter and killer roles in a single airframe.Donald and March 2001, p. 50. The last AF retired from active service on 31 August 1955, but it remained in service with the US Naval Air Reserve until 1957.
Variants
; XTB3F-1
:Prototypes of two-seat torpedo bomber powered by one {{cvt|2300|hp|kW}} R-2800-46 engine and a Westinghouse turbojet; three built.
; XTB3F-1S & -2S
:Two modified XTB3F-1 prototypes with turbojet removed and ventral radome, later redesignated as XAF-1.
; AF-2S
:Production variant with {{cvt|2400|hp|kW}} R-2800-48 engine, 193 built.Swanborough and Bowers 1990, p. 246.
; AF-2W
:Hunter variant with search radar in a ventral radome, 153 built.
; AF-3S
:Hunter/Killer variant similar to AF-2S with retractable MAD boom, 40 built.
; Grumman Model G-90
: Proposed combined AF-2S/-2W version, cancelled.
Operators
Surviving aircraft
File:Grumman AF Guardian, Naval Aviation Museum, Pensacola, Florida.jpg
After disposal by the U.S. Navy five Guardians saw many years service with Aero Union based at Chico, California, in the forest firefighting role, the last being retired in 1978.
;On display
;;AF-2S
- 123100 – National Naval Aviation Museum at NAS Pensacola in Pensacola, Florida. It was the seventh AF-2S produced. The aircraft was operated as a firefighter until 1978. It was acquired by the museum in 1980. It is displayed in the colors of its first Navy assignment, though still carries the number "30" on the cowling, which for many years was the aircraft's call-sign as a firefighting aircraft;[https://goodall.com.au/warbirds-directory-v6/grumman.pdf "AF-2S Guardian/Bu. 123100."] Warbird Directory: Grumman Page 26 Retrieved: 21 September 2022.
- 129233 – Pima Air and Space Museum, Tucson, Arizona. This aircraft is displayed as it appeared while serving as an aerial firefighter with Aero Union in California. During this period the distinctive empennage with twin vertical stabilizers on each horizontal tail were removed to make a more conventional appearance.[https://pimaair.org/museum-aircraft/grumman-af-2s/ "AF-2S Guardian/Bu. 129233."] Pima Air & Space Museum. Retrieved: 23 December 2021.
- 126731 – Static display at the Arizona Commemorative Air Force Museum in Mesa, Arizona, as a memorial to VAdm James B. Stockdale, who flew this aircraft early in his Navy career.[https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=N9993Z "FAA Registry: N9993Z"] FAA.gov Retrieved: 29 July 2021.[https://goodall.com.au/warbirds-directory-v6/grumman.pdf "AF-2S Guardian/Bu. 126731."] Warbird Directory: Grumman Page 26 Retrieved: 21 September 2022.
- 123088 - Chico Air Museum, Chico, California. This aircraft was owned by Aero Union in California until its purchase by a private owner some time in the mid-1970s. After suffering major damage in a crash on 20 September 1981, it was grounded until being donated to the museum on 14 September 2010. It is currently undergoing restoration.[https://aerialvisuals.ca/AirframeDossier.php?Serial=5829] Aerial Visuals Airplane Dossier. Retrieved: 1 August 2023.
Specifications (AF-2S Guardian)
File:Grumman AF-2S Guardian 3-view line drawing.png
{{Aircraft specs
|prime units?=imp
|ref=United States Navy Aircraft since 1911. Swanborough and Bowers 1976, p. 228.
|length ft=43
|length in=4
|length m=13.21
|span ft=60
|span in=8
|span m=18.49
|span note=(about 25 ft-wings folded (7.62 m))
|height ft=16
|height in=2
|height m=5.08
|wing area sqft=560
|wing area sqm=52.03
|empty weight lb=14,580
|empty weight kg=6,613
|max takeoff weight lb=22,640
|max takeoff weight kg=10,270
|eng1 name=Pratt & Whitney R-2800-48W "Double Wasp"
|eng1 type=radial engine
|eng1 number=1
|eng1 hp=2,400
|eng1 kw=1,790
|max speed mph=253
|max speed kts=276
|max speed kmh=510
|max speed note= at full throttle not to exceed 30 minutes at {{cvt|15000|ft|m}} with a gross weight {{cvt|21000|lb|kg}}
|range miles=1,500
|range nmi=1,304
|range km=2,415
|ceiling ft=15,000
|ceiling m=4600
|climb rate ftmin=1,850
|climb rate ms=9.4
|bombs={{cvt|4000|lb|kg}} of bombs, torpedoes, and depth charges
|rockets=six {{cvt|5|in|mm}} unguided High Velocity Aircraft Rockets (HVAR)
}}
See also
{{aircontent
|related=
|similar aircraft=
- Bréguet 960 Vultur
- Consolidated TBY Sea Wolf
- Douglas XTB2D Skypirate
- Fairey Gannet
- Fairey Spearfish
- Grumman TBF Avenger
- Grumman S-2 Tracker
- Nakajima B6N
- Short Seamew
|see also=
}}
References
=Notes and citations=
{{reflist}}
=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.
- Salerno, Giorgio. Hand-in-Hand: US Navy 'Hunter-Killer' Anti-Sub Teams. Air Enthusiast 111, May/June 2004, pp. 32–37. {{ISSN|0143-5450}}
- 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|978-0-87021-792-0}}.
- 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
{{Commons category|Grumman AF Guardian}}
- [https://www.scribd.com/doc/55087821 (1951) AN 01-85DAB-1 Pilot's Handbook for Navy Model AF-2S Aircraft]{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}
- {{usurped|1=[https://web.archive.org/web/20080605225040/http://www.vectorsite.net/avguard.html Grumman AF Guardian at Greg Goebel's Air Vectors]}}
- [https://web.archive.org/web/20070716171620/http://www.arizonawingcaf.com/pages/guardian.html AF2S Guardian at Arizona Wing Commemorative Air Force]
{{Grumman aircraft}}
{{USN attack aircraft}}
{{USN torpedo aircraft}}
Category:1940s United States anti-submarine aircraft
Category:Single-engined tractor aircraft
Category:Carrier-based aircraft
Category:Aircraft first flown in 1945
Category:Aircraft with retractable conventional landing gear