Grumman AF Guardian

https://en.wikipedia.org/wiki/Grumman_AF_Guardian

The Grumman AF Guardian was the first purpose-built anti-submarine warfare (ASW)
carrier-based aircraft to enter service with the United States Navy. 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-engined Grumman S-2 Tracker. The Guardian was the largest single-engine
piston-powered carrier aircraft ever to see service.

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

However, this too was considered impractical, 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
turbojet in the tail. Originally, the Westinghouse engine was to be the new X24C
which was to emerge as the J34 series. 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-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.

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). The hunter
aircraft would not carry any armament, 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. 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.


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

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, with full
service introduction shortly after with VS-25. 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.

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. The last AF retired from active service on 31 August
1955, but it remained in service with the US Naval Air Reserve until 1957.

Specifications (AF-2S Guardian)

General characteristics
Crew: three (four in AF-2W variant)
Length: 43 ft 4 in (13.21 m)
Wingspan: 60 ft 8 in (18.49 m) (about 25 ft-wings folded (7.62 m))
Height: 16 ft 2 in (5.08 m)
Wing area: 560 ft² (52.03 m²)
Empty weight: 14,580 lb (6,613 kg)
Max. takeoff weight: 22,640 lb (10,270 kg)
Powerplant: 1 × Pratt & Whitney R-2800-48W "Double Wasp" radial engine, 2,400 hp
(1,790 kW)

Performance
Maximum speed: 253 mph at full throttle not to exceed 30 minutes at 15,000 ft,
gross weight 21,000 pounds (276 kn, 510 km/h)
Range: 1,500 mi (1,304 nmi, 2,415 km)
Service ceiling: 15,000 ft (4600 m)
Rate of climb: 1,850 ft/min (9.4 m/s)

Armament

Rockets: 6× 5 in (127 mm) unguided High velocity aircraft rocket (HVAR) rockets
Bombs: 4,000 lb (1,814 kg) of bombs, torpedoes, and depth charges



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