P6M SeaMaster
A P6M-2 SeaMaster on the water at speed.
Type	Patrol flying boat
Manufacturer	Glenn L. Martin Company
Maiden flight	14 July 1955
Primary user	United States Navy
Number built	12

The Martin P6M SeaMaster, built by the Glenn L. Martin Company, was a 1950s strategic bomber flying boat for the United States Navy that almost entered service; production aircraft had been built and Navy crews were undergoing operational conversion, with a service entry about six months off, when the program was cancelled on August 21, 1959. A flying boat is a specialised form of Aircraft that is designed to take off from and land on water using its Fuselage as a floating hull. An aerospace manufacturer is a company or individual involved in the various aspects of designing building testing selling and maintaining Aircraft, Aircraft parts The Glenn L Martin Company was an early US Aircraft company founded by aviation pioneer Glenn Luther Martin. The maiden flight of an Aircraft is the first occasion on which an aircraft leaves the ground of its own accord Events 1223 - Louis VIII becomes King of France upon the death of his father Philip II of France. Year 1955 ( MCMLV) was a Common year starting on Saturday (link displays the 1955 Gregorian calendar) The Glenn L Martin Company was an early US Aircraft company founded by aviation pioneer Glenn Luther Martin. The 1950s Decade refers to the years of 1950 to 1959 inclusive A strategic bomber is a heavy type Aircraft designed to drop large amounts of ordnance onto a distant target for the purposes of debilitating an enemy's A flying boat is a specialised form of Aircraft that is designed to take off from and land on water using its Fuselage as a floating hull. Events 1192 - Minamoto Yoritomo becomes Seii Tai Shōgun and the De facto ruler of Japan. The year 1959 ( MCMLIX) was a Common year starting on Thursday (link will display full calendar of the Gregorian calendar. Envisioned as a way to give the Navy a strategic nuclear force, the SeaMaster was eclipsed by the Polaris submarine launched ballistic missile. The Polaris missile was a submarine-launched two-stage solid-fuel nuclear-armed ballistic missile ( SLBM) built during the Cold War by Lockheed for Submarine-launched ballistic missiles or SLBM s are Ballistic missiles delivering Nuclear weapons that are launched from Submarines Modern variants Due to the political situation at the Pentagon, the Navy promoted the P6M primarily as a high speed minelayer. ^[1]

Contents 1 Design and development 2 Operational history 3 Specifications (P6M-2) 4 See also 5 References

Design and development

In the immediate postwar defense climate, the United States Air Force's Strategic Air Command was the linchpin of the United States' security as the sole means of delivery of the nation's nuclear arsenal. The Strategic Air Command (SAC was both a major command and a "specified command" in the U The Navy saw its strategic role being eclipsed by the Air Force and knew both its prestige and budgets were at stake. Its first attempt, the USS United States, a large 'super carrier' to launch Navy strategic bombers from, having been a victim of budget cuts, the Navy chose instead to create a "Seaplane Striking Force" useful for both nuclear and conventional warfare, including reconnaissance and minelaying. Design Early design discussions included debate on the aircraft carrier's mission Groups of these planes, supported by seaplane tenders or even special submarines, could be located closer to the enemy, and as mobile targets would be harder to neutralize. A seaplane tender (or seaplane carrier) is a Ship that provides facilities for operating Seaplanes These ships were the first Aircraft carriers A submarine is a Watercraft that can operate independently below water as distinct from a Submersible that has only limited underwater capability

The requirement, issued in April 1951, was for a seaplane able to carry 30,000 lb (13,600 kg) of bombs to a target 1,500 miles (2,400 km) away from its aquatic base. This is a list of Aviation -related events from 1951: Events February February 21 - an English Electric Canberra The aircraft had to be capable of a low altitude attack run at Mach 0. Mach number (\mathrm{Ma} or M (generally ˈmɑːk sometimes /ˈmɑːx/ or /ˈmæk/ is the speed of an object moving through air or any Fluid 9 (1,100 km/h), which required an extremely capable aircraft. Both Convair and Martin submitted proposals, and the Martin one was chosen as more promising. The Consolidated Vultee Aircraft Corporation, commonly known as Convair, was a US aerospace development and manufacturing complex of the 1940s and later An order for two prototypes was issued, which was projected to lead to six pre-production aircraft and a projected twenty-four production planes.

Originally the plane was to have a Curtiss-Wright turbo-ramjet engine, but this ran into problems and a more conventional Allison J71-A-4 turbojet was employed, fitted in pairs in overwing pods to keep the spray out of the intakes. A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of Jet engine that contains no major Moving parts. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout Wings swept at 40° were used; they displayed a notable anhedral (downward slope to the tip) and were designed with tip tanks that doubled as floats on the water. Dihedral is the upward angle from horizontal of the wings or tailpane of a Fixed-wing aircraft or the wing of a Bird. Many features of Martin's XB-51 bomber prototype were used, including an all-flying "T" tail and a rotating bomb-bay—pneumatically sealed against seawater in the P6M. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout

Operational history

First flights of the XP6M-1 in 1955 showed that the engines were mounted too closely to the fuselage and scorched it when afterburners were used, leading to pointing the engines a little outward in subsequent aircraft. This is a list of Aviation -related events from 1955: Events February February 26 - George F Flight testing was initially successful but on 17 December 1955 was marred by accident, a control system fault destroying the first prototype with the loss of all four lives aboard. Events 546 - Gothic War (535–554: The Ostrogoths of King Totila Year 1955 ( MCMLV) was a Common year starting on Saturday (link displays the 1955 Gregorian calendar) Almost a year later, on 9 November 1956, the second prototype was also destroyed, due to Martin's making a change in the horizontal stabilizer control system design without adequate evaluation before test flying the "fix," but this time the crew ejected safely. Events 694 - Egica, a king of the Visigoths of Hispania, accuses Jews of aiding Muslims sentencing all Year 1956 ( MCMLVI) was a Leap year starting on Sunday (link will display full calendar of the Gregorian calendar.

The first pre-production YP6M-1 was completed about a year later, with testing resuming in January 1958. This is a list of Aviation -related events from 1958: Events Gulfstream Aerospace founded in Savannah Georgia, USA

Five more were built in 1958 when the Navy announced that Harvey Point Defense Testing Facility in Hertford, North Carolina, would serve as the testing grounds for the fleet of Martin P6M Seamaster. The Harvey Point Defense Testing Activity facility owned by the Department of Defense, is located on a peninsula in Perquimans County North Carolina along the Albemarle Sound These aircraft were fitted with test versions of the full combat equipment suite and were used for bombing, minelaying and reconnaissance evaluations. The P6M-1 test program was mostly successful, however the J71 engines proved far less reliable than necessary. The P6M-1 also had spray ingestion problems at gross weight which would preclude takeoffs except under ideal conditions. ^[2] The P6M-1 also had a serious control deficiency due to porpoising under some trim settings. ^[3] These deficiencies resulted in the P6M-1 program being cut as it was no longer considered possible for it to be a successful asset. The P6M-1 had been generally successful, the airplane was designed to meet an incredibly demanding set of specifications and had mostly achieved them.

The Navy and Martin felt that a new version, the P6M-2 would provide a useful aircraft. The first was rolled out in early 1959. Changes included new, more powerful Pratt & Whitney J75 engines, an inflight refuelling probe, improved avionics, and a canopy with better visibility. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout Aerial refueling, also called air refueling, in-flight refueling ( IFR) air-to-air refueling ( AAR) or tanking, is A buddy refuelling drogue kit had also been developed to fit in the bomb bay. Three had been built by summer 1959 and Navy crews were moving them through operational conversion when the program was abruptly cancelled in August of that year.

The P6M-2 was certainly an impressive aircraft; its Mach 0. 9 (1,100 km/h) performance "on the deck" could be equalled by few aircraft of the time and not too many more now. The planes were built incredibly tough, with the aircraft skin at the wing roots over an inch (25 mm) thick. The men managing the test program were shocked, however, when the docile and pleasant handling characteristics of the P6M-1 were replaced by some severe compressibility effects above Mach 0. 8. These included rapid changes in directional trim, severe buffeting, and wing drop requiring high control inputs to counter. Until those problems were fixed the P6M-2 could not be considered for use by the Fleet. ^[4] The problems were caused by the larger engine nacelles required for the J75s. There were also problems on the water including a tendency for the tip floats to dig in, under certain situations, and engine surges. While all of these problems were eventually solved, time had run out for the SeaMaster just as the first crews were training for its operational debut. The major defense budget cuts of the Eisenhower administration were forcing the Navy to make choices. In August 1959 Martin was told to halt operations, program was going to be cancelled. Seaplanes were a small community in Naval Aviation, and the P6M, way over budget and behind schedule, was competing with aircraft carriers for money. The Navy had a far superior system about to come on line to handle the nuclear strike role, the Fleet Ballistic Missile Submarine.

Although the technology of the P6M was phenomenal, in the age of the ICBM and SLBM, the manned bomber was considered an expensive, unreliable way to deliver nuclear weapons. When that manned bomber was also a troubled system only supported by a small part of the greater Navy, it was a doomed system. The P6M program had already cost $400 million (about $2. The United States dollar ( sign: $; code: USD) is the unit of Currency of the United States; it has also been 5 billion in 2004 dollars) and could not be justified without the strategic mission. "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again "

All of the aircraft were scrapped. Some tail sections were retained for testing, and one of these is now in the Glenn L. Martin museum, along with some wingtip floats re-used by a Martin employee to build a catamaran. A catamaran (From Tamil 'kattumaram' is a type of Multihulled Boat or Ship consisting of two hulls or vakas joined by some

Martin tried unsuccessfully to market the technology in the civilian market, but there were no takers, and the company soon abandoned the aircraft business entirely to focus on missiles and electronics. The P6M was the final aircraft constructed by the Glenn L. Martin Company.

Specifications (P6M-2)

General characteristics

• Crew: 4
• Length: 134 ft 0 in (40. 84 m)
• Wingspan: 102 ft 11 in (31. The wingspan (or just span) of an airplane or a Bird, is the distance from the left wingtip to the right wingtip 37 m)
• Height: 32 ft 5 in (9. 88 m)
• Wing area: 1,900 ft² (180 m²)
• Empty weight: 91,300 lb (41,400 kg)
• Loaded weight: 120,000 lb (54,000 kg)
• Max takeoff weight: 176,400 lb (80,000 kg)
• Powerplant: 4× Pratt & Whitney J75-P-2 turbojets, 17,500 lbf (77. The Maximum Takeoff Weight or Maximum Takeoff Mass of an Aircraft is the maximum weight at which the pilot of the aircraft is allowed to attempt to take off Pratt & Whitney is an American Aircraft engine manufacturer of products widely used in both civil and military aircraft. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout TurboJET (噴射飛航 is the brand name for the operations of the Hong Kong -based Shun Tak-China Travel Ship Management Limited (信德中旅船務管理有限公司 8 kN) each

Performance

• Maximum speed: 550 kt (630 mph, 1,010 km/h)
• Range: 1,700 nm (2,000 mi, 3,200 km)
• Service ceiling 40,000 ft (12,000 m)
• Rate of climb: ft/min (m/s)
• Wing loading: 63 lb/ft² (310 kg/m²)
• Thrust/weight: 0. In Aviation, V-speeds or Velocity-speeds are standard terms used to define Airspeeds important or useful to the operation of Aircraft, such The maximal total range is the distance an Aircraft can fly between Takeoff and Landing, as limited by fuel capacity in powered aircraft or cross-country In Aeronautics, a ceiling is the maximum Density altitude an aircraft can reach under a set of conditions In Aerodynamics, the rate of climb RoC is the speed at which an Aircraft increases its Altitude. In Aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing Thrust-to-weight ratio is as its name suggests the ratio of instantaneous Thrust to Weight (where weight means weight at the Earth ’s surface 58

Armament

• Guns: 2× 20 mm cannon in tail turret
• Bombs: 30,000 lb (14,000 kg)

See also

• Stanley Aviation ejection seats
  

Comparable aircraft

• P5M Marlin
• Beriev Be-10
  

Related lists

• List of flying boats and seaplanes
• List of military aircraft of the United States
  

References

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