P.Bowers Curtiss Aircraft 1907-1947 (Putnam)
H-10 - A twin-engined flying-boat larger than the H-8 and having the Curtiss OX engines installed as tractors. On the H-10, two booms were used to connect the engine nacelles to the horizontal tail.
C.Owers The Fighting America Flying Boats of WWI Vol.1 (A Centennial Perspective on Great War Airplanes 22)
The Curtiss H-7
The Curtiss Company were also developing the America boat under the direction of William L. Gilmore, Chief Engineer of the Company. What interaction there was with Porte is unknown. Unfortunately little is known about these aircraft, some only being known as they were recorded in photographs. The Curtiss H-7 was a three-seat, twin-engined tractor large flying boat known as the Super America. A cockpit for an observer was provided ahead of the pilot’s cockpit where the two pilots sat side by side. It has been described as a transitional boat as it featured a hull with two outrigger booms bracing the engine beds to the horizontal stabilizers. The hull extensions were externally braced rather than being faired into “fins”. Two were ordered for Russia by July 1915. The boat was built at the Churchill Street plant in Buffalo. On its first flight on October 19, 1915, the pilot, Theodore C. McCauley, who was flying solo, lifted off the lake surface the aircraft climbing at a steep angle. McCauley was alarmed and pushed the controls forward to avoid a stall. This had no effect, so he cut the power to the Curtiss V engines and the machine hit the water more or less under control. The overhanging panel on the top wing was damaged in the incident. The H-7 was tail heavy requiring 200 lbs of ballast in the forward cockpit to enable the aircraft to fly level. The machine was re-rigged, the engines and equipment being moved forward.
The test flights were concluded on December 13, McCauley having made 14 flights with the first and two with the second flying boat. The boats were then loaded to be shipped to Russia
It had been concluded that the hull needed redesign, and a new hull was constructed. This hull was used in trails conducted at Newport News, Virginia. These were long over water flights with full load and crew. The flights impressed the US Coast Guard and Curtiss donated a H-7 to the USCG. McCauley established three new world records in a H-7 on 30 April 1916. This would appear to be the machine with the new hull.
While on a flight to Washington, DC, one propeller shattered and the pieces flew into the other propeller while the machine was in a climbing attitude. At only 100 feet altitude, McCauley had little time to react as the machine turned upside down and crashed into the Potomac River. Two crew members were killed and McCauley was hospitalised due to a rigging wire striking him.
The problems that the H-7 boats had in Russia were due to the conditions they were shipped in and the fact that the Curtiss Model V engines were in the development stage. The aircraft suffered in the heat of the ship’s hold and then the high humidity of the Russian seacoast. The propellers warped and vibrated causing problems with the engines to manifest themselves. The Russian ground crew were unused to handling such aircraft and their rough handling caused the bottoms of the hull to drop out when taking off and caving in on alighting.
Curtiss records show two H-7 boats built in April and four in June 1916. What happened to these boats is unknown but parts are thought to have been used in manufacturing the H-8 and possibly the H-14. The H-14 was recorded by Lt (jg) W. Capehart, the USN officer at Curtiss, Buffalo, as having an H-7 hull with H-4 wings and control surfaces.
Curtiss H-7 Specifications
Source Note 1 Note 2
Length 39 ft 2 in 39 ft 1 in
Span upper 77 ft 0 in 77 ft 0 in
Span Lower 49 ft 2 in 49 ft 2 in
Chord 7 ft 21/32 in -
Gap 7 ft 5 1/2 in -
Dihedral - 1°
Sweepback - 3° 27’
Net Weight 4,500 lbs 4,500 lbs
Gross Weight 6,500 lbs 6,500 lbs
Useful Load - 2,000 lbs
Fuel (4 hours) - 815 lbs
Oil Weight - 145 lbs
Water Weight - 110 lbs
Pilot Weight - 160 lbs
Passenger Wt., ammunition or other load - 760 lbs
Time to 2,700 ft - 10 min
Source Notes: (1) “American Air Transport Services”, Flight, 31.03.21, P.230. (2) Curtiss Specification Sheet. Smithsonian NASM File AC-901659-01 Curtiss Model H-7. Casey uses the same figures.
The H-10 was a large twin engined boat with two booms connecting the engine nacelle to the horizontal tail. The power plants were Curtiss 160-hp VX engines. Aerial Age for 22 May 1916, reported that the H-10 had been wrecked near Alexandria, Va., on the 10th.
The accident was caused by the breaking of one propeller, pieces of which struck the other propeller, causing it to break also and thus making a quick forced landing necessary from a height of 100 feet. There was a strong wind blowing and one wing struck the water first, which, together with the speed at which the machine was moving, probably over 100 miles per hour, caused the craft to spin about and strike broadside causing its complete wreck.
There were five men aboard and none wore life jackets. Three were picked up by a tug which, assuming that this was the whole crew, moved away from the wreckage. Once one of the crew recovered enough to tell the captain that there were two missing, the tug returned but was not able to locate them.
Those rescued were Theodore Macaulay (sic), Phillip Utter, Mayo Dudley, newspaperman, while those that lost their lives were Louis Grant and Charles A. Good. None of the former were seriously injured.