When is an F-15 not an Eagle? When it’s an XF-15C-1 !
Tags: 'mixed power concept', 'strike package', 1350 hp, 1600 lb st, 2100 hp, 2700 lb st, 27th February 1945, 469 mph at 23000 ft, aircraft, Allis-Chalmers J36, Aviation, aviation is full of blind alleys, blind alley, carrier aircraft, carrier deck, Curtiss Aeroplane and Motor Company, Curtiss-Wright XP-55 Ascender, De Havilland, De Havilland Goblin turbojet, designated XF-15, early jet engines, England via New Zealand, faulty landing approach, FR-1 squadron, General Electric J31-GE-3, jet engine, jet engine and naval aviation, jet engine for dash speed and combat, land-based aircraft, Maryland, mixed-power fighters, museum, Museums, Naval Air Test Center, naval aviation, New England, obsolete before they even flew, one of the three prototypes crashed, outmoded operational concepts, P-40, P-51 Mustang, Patuxent River, piston engine for cruise, Pratt & Whitney R-2800, preserved in California, programme cancelled in October 1946, protect the fleet, quirky designs, Quonset Air Museum, Rhode Island, Ryan FR-1 Fireball, Second World War, slow to 'spool up', sole survivor, standing patrols, structural failures, T-tail, type withdrawn in August 1947., U S Navy, USA, Wright R-1820-72W Cyclone, XF-15 was not a great performer, XF-15C-1
Aviation is full of blind alleys, quirky designs which seemed to be good ideas at the time, or aircraft built to outmoded operational concepts which were obsolete before they even flew. The XF-15C-1 is just such an oddity. At the start of this year’s road trip with my friend David (over from England, via New Zealand) I told him, ‘You have to see this thing in Rhode Island!’
The jet engine and naval aviation were not an easy marriage in the beginning. A carrier aircraft needed to have much greater endurance than the average land-based aircraft, because of the distance a ‘strike package’ would have to travel, and the standing patrols that fighters would need to undertake in order to protect the fleet. When you add the fact that the early jet engines were very ‘thirsty’, and also slow to ‘spool up’ when you needed power in a hurry, you could see how it became very difficult correct a faulty landing approach to a carrier deck.
It would seem logical therefore that a ‘mixed power’ concept might prove to be the way forward – a piston engine for cruise, with the addition of a jet engine for dash speed and combat. This was successfully accomplished with the Ryan FR-1 Fireball (1 x Wright R-1820-72W Cyclone of 1,350 hp, 1 x General Electric J31-GE-3 of 1,600 lb st). Despite the fact that the first and only FR-1 squadron was formed in the early months of 1945, it saw no combat, mainly due to a number of structural failures which eventually caused the type to be withdrawn in August, 1947.
The aircraft you can see here (on display at Quonset Air Museum, Rhode Island), is the last survivor of an attempt to ‘build a better mouse trap’ – in other words, to take the ‘mixed power concept’ to the next level. The Curtiss Aeroplane and Motor Company, were asked to build a series of three prototypes of a mixed power fighter aircraft, designated XF-15. The choice of Curtiss was somewhat puzzling, as they were notorious for designing mediocre fighters. Every single fighter prototype they had built after the P-40 had been a failure, including the radical Curtiss-Wright XP-55 Ascender. It was no surprise, therefore, that the XF-15 was not a great performer, despite having a Pratt & Whitney R-2800 of 2,100 hp and an Allis-Chalmers J36 of 2,700 lb st (a licence-built De Havilland Goblin turbojet). The first XF-15C-1 flew on 27th February, 1945, and had a tailplane mounted at the mid-point of the fin. The other two aircraft (numbers 2 and 3) were given a T-tail, to try to improve controllability. Even using both engines, the aircraft could not reach more than 469 mph at 23,000 ft; this was in a period when standard P-51 Mustangs were reaching 441 mph. One of the three prototypes crashed, another was scrapped after only two flights and the whole programme cancelled in October, 1946.
The sole survivor is shown here at Quonset Air Museum, where it is being slowly restored; it is in the markings of the Naval Air Test Center, Patuxent River, Maryland. The surviving Ryan FR-1 Fireball (preserved in California), and this XF-15C-1 are the last remaining remnants of the U.S. Navy’s experiment with mixed-power fighters – a venture down an interesting blind alley.