Douglas Skyrocket

The Douglas Aircraft Company constructed the Douglas D-558-2 Skyrocket (or D-558-II), a supersonic research aircraft that was powered by both rocket and jet engines, for the United States Navy.

On the 20th of November in 1953, just prior to the 50th anniversary of powered flight on the 17th of December, Scott Crossfield successfully piloted the Skyrocket to a speed of Mach 2, which equates to over 1,290 mph (2076 km/h).

This marked the first instance in which an aircraft had surpassed twice the speed of sound.

The aircraft’s designation included a “2” to indicate that the Skyrocket was the second phase of a three-phase program.

The initial phase, the D-558-1, was equipped with jet propulsion and straight wings.

The third phase, which was never realized, would have entailed constructing a mock-up of a combat aircraft that incorporated the findings from the testing of the first two phases.

The D-558-3 design, which was never constructed, was for a hypersonic aircraft that resembled the North American X-15.

When it became apparent that the D558-1 fuselage could not be modified to accommodate both rocket and jet power, the D558-2 was developed as a completely new aircraft.

On January 27, 1947, a contract change order was issued to formally abandon the final three D558-1 aircraft and replace them with three new D558-2 aircraft.

The Skyrocket featured wings with a 35-degree sweep and horizontal stabilizers with a 40-degree sweep.

The wings and empennage were constructed of aluminium, while the large fuselage was primarily made of magnesium.

The Skyrocket was powered by a Westinghouse J34-40 turbojet engine, which was fed through side intakes in the forward fuselage and intended for take-off, climb, and landing.

For high-speed flight, a four-chamber Reaction Motors LR8-RM-6 engine (the Navy designation for the Air Force’s XLR11 used in the Bell X-1) was installed.

This engine was rated at 6,000 lbf (27 kN) static thrust at sea level.

The fuselage tanks carried a total of 250 US gallons (950 L) of aviation fuel, 195 US gallons (740 L) of alcohol, and 180 US gallons (680 L) of liquid oxygen.

The Skyrocket was initially designed with a flush cockpit canopy, but the visibility from the cockpit was inadequate.

As a result, the cockpit was reconfigured with raised conventional angled windows, which increased the profile area at the front of the aircraft.

This was balanced by adding an additional 14 inches (36 cm) of height to the vertical stabilizer.

Similar to its predecessor, the D558-1, the D558-2 was designed so that the forward fuselage, including the cockpit, could be separated from the rest of the aircraft in an emergency.

Once the forward fuselage had decelerated sufficiently, the pilot could escape from the cockpit using a parachute.
Skyrocket Aircraft Serial Numbers
D-558-2 (1)
37973, NACA-143, 123 flights
D-558-2 (2)
37974, NACA-144, 103 flights
D-558-2 (3)
37975, NACA-145, 87 flights
42 ft (13 m)
25 ft (7.6 m)
12 ft 8 in (3.86 m)
Wing area
175 sq ft (16.3 m2)
NACA 63-010
NACA 63-012
Launch weight turbojet only.
10,572 lb (4,795 kg)
Launch weight mixed power.
15,266 lb (6,925 kg)
Launch weight rocket only.
15,787 lb (7,161 kg)
Fuel capacity
Turbojet fuel capacity
250 US gal (210 imp gal; 950 L) Avgas
Rocket fuel capacity
195 US gal (162 imp gal; 740 L) Alcohol
Rocket oxidiser capacity
180 US gal (150 imp gal; 680 L) LOX
Turbopump H2O2 capacity
11 US gal (9.2 imp gal; 42 L) High Test Hydrogen Peroxide (HTP)
1 × Westinghouse J34-WE-40 turbojet engine,
3,000 lbf (13 kN) thrust.
1 × Reaction Motors XLR8-RM-5,
4-chambered liquid-fuelled rocket engine,
6,000 lbf (27 kN) thrust.
Maximum speed
585 mph (941 km/h, 508 kn) at 20,000 ft (6,100 m)

On turbojet only
720 mph (630 kn; 1,160 km/h) at 40,000 ft (12,000 m)

On mixed power with conventional take-off
1,250 mph (1,090 kn; 2,010 km/h) at 67,500 ft (20,600 m) on rocket power air-launched
Stall speed
160 mph (260 km/h, 140 kn)
Rate of climb
22,400 ft/min (114 m/s) mixed power
11,100 ft/min (3,400 m/min) rocket power only
Wing loading
60.4 lb/sq ft (295 kg/m2) turbojet engine only
87.2 lb/sq ft (426 kg/m2) mixed power
90.2 lb/sq ft (440 kg/m2) rocket engine only
McDonnell Douglas aircraft since 1920: Volume I-René J Francillon.
San Diego Air and Space Museum Archive.
The National Museum of the U.S. Air Force.
X-Planes, Douglas D-558-D-558-1 Skystreak & D-558-2 Skyrocket-Peter E Davies, Adam Tooby.

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