Curtiss NC-4 before Transtlantic Flight
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The Curtiss NC (Navy-Curtiss) was a flying boat originally designed in 1917 to be able to cross the Atlantic to reach the war zone, but that became most famous for making the first successful trans-Atlantic flight in May 1919, a few months before Alcock and Brown’s more famous first non-stop flight.
The original idea behind the development of the NC was to produce an aircraft that could easily cross the Atlantic and then almost immediately enter combat in the war zone around the British Isles. The aircraft was designed by a joint naval and Curtiss team, which included Commander Jerome Hunsaker and Commander Holden Richardson, who designed the hull. Apart from the hull most of the detailed work was carried out by Curtiss’s engineers.
The combined design teams came up with a wide span biplane, with a span of 126ft 0in (on a par with the German ‘R’ class giants that bombed London). It was to be powered by three tractor engines, mounted between the wings (although this arrangement was soon changed). The aircraft had a fairly short hull which had been designed by the Navy and carried a crew of five. It had a biplane tail, with a single rudder carried between the upper and lower horizontal tail surfaces. The tail was connected to the hull and upper wing by a framework of booms, in order to give the rear gunners a better field of fire.
The US Navy originally ordered ten aircraft, four to be built by Curtiss and six at the Naval Aircraft Factory. However the war ended before any of the Naval aircraft had been built, and all six were cancelled. By this point the Navy had already paid to have Curtiss’s Garden City, New York factory expanded, and NC-1 had been completed, so the Navy decided to complete all four aircraft and use them for a trans-Atlantic flight.
Each of the Curtiss aircraft was slightly different.
NC-1 was completed with three 360hp Liberty engines in tractor configuration. It made its maiden flight on 4 October 1918 with Commander Richardson at the controls. In November 1918 it set a record by carrying 51 passengers plus its crew, but despite this it was discovered that it couldn’t take off with enough fuel for the trans-Atlantic flight. As a result it was given a fourth Liberty engine. The middle engine was raised, and the new engine was placed below it, powering a pusher propeller.
NC-2 went through the most dramatic changes. It was built with three engines, with the outer engines as tractors and the middle engine as a pusher. The pilot’s cockpit was built into the front of the nacelle for the pusher engine. It was completed in this layout in February 1919. This layout was soon abandoned, and it was given four engines, carried in tandem pairs in the outer nacelles, with one pusher and one tractor in each. At first the cockpit remained in the pusher nacelle, but it was then moved down into the hull allowing the otherwise empty nacelle to be removed. However soon after this change was made the NC-2 was wrecked in a storm. It was then used as a source of spare parts for the other three.
NC-3 was completed with the same four-engined layout that had been installed on the modified NC-1, and was designated as the NC-TA. It made its maiden flight in April 1919.
NC-4 was also completed with the NC-1 four-engined layout.
Only three aircraft were thus available for the trans-Atlantic flight. They were organised into Seaplane Division One, commanded by Captain H. Towers, who used NC-3 as his flagship.
The trans-Atlantic flight was a major effort. It was supported by a line of warships (mainly destroyers), which lined the route at regular intervals to act as guide aircraft and rescue ships. The route involved a series of shorter stages, travelling via the Azores to reach Portugal and then Britain.
The three aircraft left Trepassey Bay, Newfoundland, on 16 May 1919. NC-1 and NC-3 were both forced down into the sea short of the first stop, at Horta in the Azores. NC-1 had to be abandoned and the crew rescued, but NC-3 was able to taxi to Horta. However it was unable to take off again. NC-4 was able to push on, and after stops at Horta, Ponta Delgada, Lisbon and Ferrol del Caudillo arrived at Plymouth on 31 May. The total journey from leaving Rockaway, New York, on 8 May to the arrival at Plymouth, took 57 hours 16 minutes of flight time and covered an impressive 3,925 miles.
After the war six NAF aircraft were completed (serial numbers A5632-A5634, A5885 and A5886. The first two used the three engine layout, with two tractors and a pusher, while the other four used the four engine layout of the NC-3 and NC-4. In 1922 the remaining aircraft officially became the NAF P2N, although the new designation wasn’t actually used.
Curtiss NC-4
Engine: Four Liberty 12A inline piston engines
Power: 400hp each
Crew: 5
Span: 126ft 0in
Length: 68ft 3in
Height: 24ft 5in
Empty weight: 16,000lb
Maximum take-off weight: 28,000lb
Max speed: 85mph
Service ceiling: 2,500ft
Endurance: 14 hours 45 minutes at cruising speed
Curtiss NC-3 at Ponta Delgada, May 1919