Martin P5M Marlin

https://en.wikipedia.org/wiki/Martin_P5M_Marlin

The Martin P5M Marlin (P-5 Marlin after 1962), built by the Glenn L. Martin
Company of Middle River, Maryland, was a twin-piston engined flying boat that
entered service in 1951, and served into the late 1960s with the United States
Navy performing naval patrols. It also served with the United States Coast Guard
and the French Navy. 285 were produced overall.

Built as a successor to the PBM Mariner, it had better engines, an improved hull
form, and a more conventional tail. The XP5M Marlin prototypes were based on the
last PBM-5 Mariners, the company designation being Model 237. The type was
heavily improved, again leading to the P5M-2 (Model 237B), which was
redesignated SP-5B. A number of P5M-1 models were also used for training,
designated TP-5A (after 1962).


Role
Patrol aircraft

Manufacturer
Glenn L. Martin Company

First flight
30 May 1948

Introduction
1952

Retired
1967

Status
Retired

Primary users
United States Navy
United States Coast Guard
French Navy

Number built
285

Developed from
Martin PBM Mariner


The Marlin was designed as a gull-winged aircraft to place the engines and
propellers high above the spray. Power was provided by two Wright R-3350 radial
engines. The rear hull did not lift sharply from the water at the tail, instead
rising up steadily, a Martin innovation; this gave the aircraft a longer base of
flotation and reduced "porpoising" over waves.

The prototype had nose and tail turrets with twin 20 mm (0.79 in) cannon in
each, as well as a dorsal turret with two 0.5 in (12.7 mm) M2 Browning machine
guns. The cockpit area was the same as the Mariner's. It first flew on 30 May
1948.

The first of 167 production P5M-1 aircraft was produced in 1951, flying on 22
June 1951. Changes from the prototype included a raised flight deck for improved
visibility, the replacement of the nose turret with a large radome for the
AN/APS-44 search radar, the deletion of the dorsal turret, and new, streamlined
wing floats. The engine nacelles were lengthened to provide room for weapons
bays in the rear.

The P5M-1 was followed by 116 P5M-2 planes. These had a T-tail to put the tail
surfaces out of the spray, an AN/ASQ-8 MAD boom at the rear of the tail-tip, no
tail guns (the gun position replaced by the antenna for the AN/APN-122 Doppler
Navigation Set), better crew accommodation, and an improved bow to reduce spray
during takeoff and landing.

U.S. Navy in Vietnam

The last flying boat operations of the United States Navy were Market Time
patrols of VP-40. Maritime surveillance patrols began in February 1965 to locate
small craft transporting supplies from North Vietnam to Viet Cong units in South
Vietnam. VP-40 operated from seaplane tenders and patrolled off the Mekong delta
between Phú Qu?c and Vung Tau. The last U.S. Navy P5M, redesignated as SP-5B,
was flown to NAS Patuxent River, Maryland on 12 July 1968 for interim storage
pending construction of display area at the Smithsonian Institution in
Washington, DC. As a display area at Smithsonian did not materialize, the
aircraft was later relocated to the National Naval Aviation Museum at NAS
Pensacola, Florida where it is currently on display.

The Marlin was in service during the 1962 Cuban missile crisis.

U.S. Coast Guard

Seven P5M-1Gs and four P5M-2Gs were built for the United States Coast Guard for
air-sea rescue service, but they found the planes difficult to maintain and
surplus to requirements. They were subsequently transferred to the U.S. Navy,
which redesignated them as TP-5As and used them as training aircraft, since they
had no provision for armament.

French Navy

The French Navy took delivery of ten former U.S. Navy Marlins between 1957 and
1959 to replace Short Sunderlands in maritime patrol service, based out of
Dakar, Senegal in West Africa. They were returned in 1964.

Specifications (P5M-2)

General characteristics
Crew: 11
Length: 100 ft 7 in (30.7 m)
Wingspan: 117 ft 2 in (35.7 m)
Height: 32 ft 9 in (10.0 m)
Wing area: 1,406 ft² (130.1 m²)
Empty weight: 50,485 lb (22,900 kg)
Loaded weight: 72,600 lb (33,000 kg[citation needed])
Max. takeoff weight: 85,000 lb (38,600 kg)
Powerplant: 2 × Wright R-3350-32WA radial engines, 3,450 hp (2,570 kW) each

Performance
Maximum speed: 218 kn (404 km/h, 251 mph)
Cruise speed: 130 kn (242 km/h, 150 mph)
Range: 1,783 nmi (3,300 km, 2,050 mi)
Service ceiling: 24,000 ft (7,300 m)
Rate of climb: 1,200 ft/min (6.1 m/s)
Wing loading: 60.5 lb/ft² (287 kg/m²)
Power/mass: 0.081 hp/lb (0.13 kW/kg)

Armament

4 × 2,160 lb (980 kg) torpedoes or
4 × 2,000 lb (907 kg) mines or bombs or
8 × 1,000 lb (454 kg) mines or
16 × 500 lb (227 kg) bombs or
16 × 330 lb (150 kg) depth charges or
1 × Mk.90 "Betty" nuclear depth charge

Avionics

AN/APS-44 radar (later replaced by AN/APS-80 radar)




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