Martin P5M Marlin
The Martin P5M Marlin, built by the Glenn L. Martin Company of Middle River, Maryland, is 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, with 285 being produced.
Development
Built as a successor to the PBM Mariner, it had better engines, an improved hull, and a single vertical fin 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, which was redesignated SP-5B. A number of P5M-1 models were also used for training, designated TP-5A.Design
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 XP5M-1 had nose and tail turrets with twin cannon in each, as well as a dorsal turret with two 0.5 in 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, better crew accommodation, and an improved bow to reduce spray during takeoff and landing.
Operational history
U.S. Navy
The last flying boat operations of the United States Navy were Operation Market Time patrols by Patrol Squadron 40 during the Vietnam War. 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 Quốc and Vung Tau.VP-40 carried out the final U.S. Navy Marlin flight, which landed on San Diego Bay in California on 6 November 1967.
The last U.S. Navy P5M, redesignated an SP-5B in 1962, was flown to Naval [Air Station Patuxent River], Maryland, on 12 July 1968 for interim storage pending construction of a display area for it at the Smithsonian Institution in Washington, D.C. As a display area at the Smithsonian did not materialize, the aircraft later was moved to the National [Naval Aviation Museum] at Naval Air Station Pensacola, Florida, where it is was on display as of 2010.
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 the Coast Guard found the planes difficult to maintain and surplus to requirements. They were subsequently transferred to the U.S. Navy, which redesignated them TP-5As and used them as training aircraft because 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. They were based at Dakar, Senegal, in West Africa. They were returned to the U.S. Navy in 1964.Variants
Company designations
;M-237: Company designation for P5M-1;M-237B: Company designation for P5M-2
;M-270: XP5M-1 prototype converted with a revised hull.
;M-290: Company designation for P5M-3 which was completely revised into the unbuilt four-engine P7M SubMaster
Pre-1962 designations
;XP5M-1;P5M-1
;P5M-1G
;P5M-1S
;P5M-1T
;P5M-2
;P5M-2S
;P5M-2G
;P5M-3
Post-1962 designations
;P-5A;SP-5A
;TP-5A
;P-5B
;SP-5B
Operators
; France; United States
- United States Coast Guard
- United States Navy
Surviving aircraft