The Seamaster was designed to a 1952 specification for a flying boat patrol plane/bomber. Martin was given a contract for a design study and then two prototypes. The P6M was to be modern in every sense of the word, essentially a seagoing B-52 with a crew of four and a gross weight of about 160,000 pounds!. Power was to be provided by 4 Pratt and Whitney J-57 turbojets of 17,500 pounds of thrust mounted on top of the wings. Wing span of the Seamaster was 100 feet with a lenght of 134 feet and incorporating a T-tail. The wing tip floats were an integral part of the drooping wing. The floats were also important for the beaching and docking of the Seamaster. Another feature of the P6M was the watertight rotary bombbay. The bombbay would rotate inflight exposing the bomb racks which could hold bombs, mines, cameras or other stores.
Flight testing begin in July 1955 and progress was encouraging when on 7 December, 1955 disaster struck. One of the fears of the flight control designers was realized. One of the horizontal stabilizer control rods went to full travel, The XP6M which was traveling at high speed pitched down so sharply that the engines tore free from the wings. The wings flexed so badly that they touched beneath the aircraft just before the Seamaster broke up killing the three crew members. The second XP6M prototype carried on with the flight testing, During a test run for special vibration checks the aircraft went into a tight loop before breaking up. Fortunately the second prototype had been modified with an escape tube as a result of the crash of #1 prototype and all the crew was able to escape the ship.
A major redesign followed the crash of the second prototype designated P6M-2, this resulted in the jet engines being angled out away from the fuselage, wings changed from anhedral or drooping, to a dihedral angle. Also a new transitorized flight control and auto-pilot system was installed. Initially the Navy had ordered 24 of the Seamasters but this was cut to eighteen due to the delays with the redesign and the increased cost of the "new" design. The first production YP6M flew in February of 1959 and the US Navy boasted of the capabilities of the new Seamaster. However the program had been reduced to eight aircraft by this time and the program was terminated in the fall of 1959 with only four of the Seamasters being built. Regretably all four were scrapped. The P^M had a top speed of 600mph and a range of 3,000 miles. Well on with the pics.
First up the Seamaster on the beaching gear coming out of the water. I think this is the -2 model.
I think this is one of the two prototypes as the jet engines do not look to be canted outward.
A couple of interesting items in this picture. On the left side foreground the tail of a Martin PBM Mariner and in the background on the left a Martin P5M Marlin. And in the right rear background a ground crew man is watering the Seamaster!
Here we have one of the P6M-2 during taxing test it look like.
A rather interesting perspective of a Seamaster. From the engines I think that this is one of the two prototypes.
And to close out tonites Flyby here is 75% of the Seamasters built in flight.
We hope everybody out there has a great weekend. Stay safe and with a bit of luck we will be back tomorrow night a Saturday Sortie.
Regards
alfa6 ;>}
