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AF Guardian

From PlaneSpottingWorld, for aviation fans everywhere
AF (TB3F) Guardian
Hunter-Killer team of AF-2W (front) and AF-2S
Type Anti-submarine aircraft
Manufacturer Grumman Aircraft Engineering Corporation
Maiden flight 1945-12-19
Introduced October 1950
Retired 1955-08-31
Status 1 in National Museum of Naval Aviation
Primary user United States Navy
Number built 389

The Grumman AF Guardian was the first purpose-built anti-submarine aircraft to enter service in the U.S. Navy, although it should be described as a system, as it required two airframes to perform its duties.


The original design, the XTB2F of 1944, was to be a twin-engined aircraft with a 3,600-pound (1,633 kg) warload and a range of 3,700 miles (5,950 km). This was considered to be too large for practical use from an Essex class aircraft carrier, and in 1945 was canceled in favor of a modified F7F Tigercat, the XTSF-1. However another alternative, the internally-developed Model G-70, was selected instead, 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 turbojet in the tail. This was found to be unsuitable and the jet engine was removed without ever having been used in flight.

The XTB3F carried a crew of two seated side-by-side and an armament of two 20 mm cannon and 4,000 pounds (1,814 kg) of bombs, torpedoes and/or 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. As all the required equipment could not be fitted into a single aircraft, two variants would be produced, one as a "hunter" and another as a "killer".

The "hunter" aircraft would not carry any armament, but instead two additional crewmembers and a ventral radome for APS-20 search radar. This aircraft, the XTB3F-1S, first flew in November 1948.

The "killer" deleted the cannon 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.

Redesignated as AF-2W (TB3F-1S) and AF-2S (TB3F-2S), the Guardian entered service in October 1950.

The largest single-engine piston-engined aircraft ever used by the U.S. Navy, 193 AF-2S Guardians were built.

In 1952, the "hunter" AF-3S 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.

The Guardian saw service in the patrol role during the Korean war, however shortly afterwards it began to be replaced by the Grumman S2F Tracker, and the last AF was retired on 31 August 1955.

Several Guardians saw service in civilian hands as water bombers, and one is on display at the National Museum of Naval Aviation in Pensacola, Florida.


Royal Netherlands Navy operated Guardians as hunters and TBFs as killers out of Valkenburg Naval Airbase at least from 1954 to 1960 as part of NATO.

Specifications (AF-2S Guardian)

General characteristics



  • Rockets: 16× 5 in (127 mm) unguided rockets
  • Bombs: 4,000 lb (1,814 kg) of bombs, torpedoes, and depth charges

External links

Related content

Comparable aircraft

Designation sequence

  • A- (attack) sequence: AF - A2F
  • TB- (torpedo bomber) sequence: TBF - TB2F - TB3F

Related lists

it:Grumman AF Guardian