Douglas D-558 Skystreak / Skyrocket

The Douglas company’s initial essay into high-speed research aircraft was the D-558-1 Skystreak which first flew on 14 April 1947 at the beginning of a programme to investigate free-flight air load measurements of the type that were then unobtainable in wing tunnel tests. The D-558-1 was fitted with a pressure-recording system connected to 400 points on the aeroplane’s surface, and powered by a 4,000-lb (1814-kg) Allison J35-A-23 turbojet yielded invaluable research data. The type was later re-engined with the 5000-lb (2 268-kg) thrust J35-A-11, and secured two world air speed records during 1947.

The three D-558-I Skystreaks were turbojet-powered aircraft that took off from the ground under their own power.

The D-558-1 Skystreak broke sound barrier in 1948. Of the three built, the first aircraft is on display at the Naval Aviation Museum in Pensacola, Florida. The second D-558-I crashed on3 May 1948, killing NACA pilot Howard C. Lilly. The third Skystreak is owned by the Carolinas Historical Aviation Museum located at the Charlotte International Airport in North Carolina.

D-558-1

Developed from the Skystreak, the D-558-II Skyrocket (first flown 4 February 1948) was built primarily to investigate the properties of swept wings for high-speed flight. The D-558-2 Skyrocket was in essence a swept-wing version of the straight-winged D-558-1 powered by a 3000-lb (1361-kg) thrust Westinghouse J34-WE-22 turbojet supplemented by a 6000-lb (2722-kg) thrust Reaction Motors XLR-8 rocket motor. The type first flew in February 1948 and the rocket engine enabled the Skyrocket to exceed Mach 1 in October 1947 and later, on 20 November 1953, with the turbojet removed and the rocket fuel capacity doubled, it reached Mach 2.01 (1327 mph) at a height of 65,000ft after being released from a Superfortress mother-plane. Three months earlier it had reached 83,235 ft after a similar launch. The D-558-II last flew on 12 December 1956.

D-558-2

The rocket-powered air-launched D-558-II Skyrocket became the first aircraft to exceed Mach 2. The first D-558-II is on display at the Planes of Fame Museum in Chino, California. The number two Skyrocket, the aircraft used by Scott Crossfield to first break Mach 2, is on display at the National Air and Space Museum in Washington DC. The last D-558-II is displayed on a pedestal at Antelope Valley College, Lancaster, California.

D-558-1 Skystreak
Engine: 1 x Westinghouse J34-WE-22 turbojet, 3200 lb thrust.
Length: 35.105 ft / 10.7 m
Wingspan: 25.098 ft / 7.65 m
Wing area: 150.696 sq.ft / 14.0 sq.m
Max take off weight: 9812.3 lb / 4450.0 kg
Top speed: 650.92 mph / 562 kt / 1040 km/h
Wing loading: 65.19 lb/sq.ft / 318.0 kg/sq.m
Crew: 1
Total Flights: 228.
Highest Flight: 83,235 feet

D-558-II Skyrocket
Engine: 1 x Westinghouse J34-WE-22 turbojet, 3200 lb thrust, & 1 x Reaction Motors XLR-8 bi-fuel rocket, 6000 lb thrust.
Wing span: 25 ft (7.62m)
Length: 45 ft 3 in (13.79m)
Height: 3.51 m / 11 ft 6 in
Wing area: 16.26 sq.m / 175.02 sq ft
Crew: 1.
Fastest Flight: 1,291 mph
Total Flights: 161
Highest Flight: 83,235 feet