Martin M-130

Second of the huge trans-oceanic flying boats used by Pan American Airways System between the wars, the Martin Model 130 resulted from the same specification to which Sikorsky had evolved the S-42. Unlike the Sikorsky design, however, the Martin 'China Clipper', as it was to become known, truly possessed the long over water capability that the airline required.

Pan Am's planned trans-Pacific route to the Philippines was San Francisco Honolulu-Midway Island-Wake Island-Guam-Manila, the five stage lengths being, respectively, 2,410, 1,380 1,260 1,450 and 1,550 miles (3,880, 2,220, 2,030, 2,333 and 3,220 km). To accomplish this it required an aircraft with a non-stop range Of 2,500 miles (4,025 km) carrying 12 passengers, which even by mid-1930S standards was hardly an economic payload/weight ratio. While the routes were being surveyed in 1935 by S-42B, Martin was building three M-130's, which in service were named China Clipper (NC14716), Philippine Clipper and Hawaii Clipper.


Of all-metal construction, the M-130 had a two-step hull, the upper portions of which were clad in corrugated duralumin sheet, and sponsons (sometimes called 'sea wings') were fitted to the hull sides at cabin floor level. These aerofoil-shaped surfaces fulfilled a dual function: they helped to stabilize the aeroplane while resting or manoeuvring on the water, and served also as storage areas for nearly half of the flying boat's 3,800 US gallon (14,383 litre) fuel load. Retractable platforms were built into the leading-edge of each wing on either side of each engine nacelle, to provide access for servicing the engines, two of which were completely changed every three trips.

The flight crew of five comprised captain, first officer, radio officer, flight engineer and steward. Aft of the flight deck, in order, were the forward passenger compartment, lounge and two rear passenger compartments. Each passenger compartment could accommodate 8 seats or 6 sleeping berths, and the lounge seated 12. Since the long distance payload was only 12 passengers altogether, one can appreciate the declaration by one American observer that passengers 'rattled around in the vast expanse of hull in a degree of comfort never known before'.

Proving flights were made in late 1935 and early 1936, China Clipper making the first ever commercial double crossing of the Pacific between November 22,1935 and December 6,1935. The full, regular trans-Pacific M-130 service opened on October 21,1936, the flight spanning five days and occupying a total of 60 hours actual flying. By 1940 (Hawaii Clipper having been lost at sea) the surviving pair of M-130s had accumulated some 10,000 flying hours each equal to an average daily utilization of 5 1/2 hours and had flown 12,718,200 passenger miles (20,467,930 passenger-km) in addition to express and mail flights.

In 1942 they were impressed for war service as US Navy transports, though not given a Naval designation. China Clipper was wrecked early in 1945, shortly after the tenth anniversary of its first flight, when it struck an unlit boat during a night landing.

An even larger flying-boat than the M-130 was built by Martin in 1937. This was the Model 156, whose design followed closely that of its predecessor except for the provision of twin fins and rudders. Powered by four 1,000 hp Wright Cyclone engines, it could accommodate 33-53 passengers (compared with a maximum of 52 in the M-130) and had a gross weight of 63,000 lb (28,576 kg).


Built by the Glenn L. Martin Company, they were known by the company as Martin Ocean Transports. The aircraft first flew on December 30, 1934. Only three of these aircraft were built, the China Clipper, the Philippine Clipper and the Hawaii Clipper. To the public, China Clipper became a generic name and originally was applied to all three of the Martin M-130's in Pan Am's fleet and, later, even to the Boeing B-314's.


With Pan American Airways.
Crew: 5 and eventually 8
Wingspan: 130 feet / 39.7 m
Length: 90 feet 10.5 inches / 27.7 m
Height: 24 feet 7 inches / 7.5 m
Gross Weight: 52252 lbs / 23701 kg
Engines: 4x Pratt & Whitney R-1830-S2A5G Twin Wasp 14-cylinder Radial Engines (830 horsepower each - later 950 hp with hydromatic propellers)
Maximum Speed: 180 mph
Cruise Speed: 163 mph
Cruise Ceiling: 17000 feet / 5182 m
Range: 3200 miles / 5150 km
Payload: 18-46 (18 night) passengers