Douglas D-558-2 Skyrocket
Following the end of World War II, the United States began a program of studying supersonic flight, with the program being run in conjunction with the National Advisory Committee for Aeronautics, the US Navy, and the US Army Air Force (soon to become the US Air Force). While Bell Aircraft built the X-1 for supersonic flight, Douglas worked on the D-558 series with much the same purpose. The company began with the D-558-1 Skystreak, which was intended to study both jet propulsion and supersonic speeds; the X-1 broke the sound barrier first, and the Skystreak, while providing valuable research on near-supersonic speeds and handling, could only reach the very beginning of supersonic speed in a dive.
Douglas had intended to equip the D-558-1 with a mixed jet/rocket propulsion, but the fuselage was too narrow. As work began to rectify this problem, Douglas’ designers learned of wartime German research into swept wings for better handling at high speeds. The Skystreak was completely redesigned into the swept-wing, larger D-558-2 Skyrocket. To test the aircraft, the first of three D-558-2s was equipped with only a jet engine, and first flew in February 1948, with rocket propulsion to be added later.
The D-558-2 was intended to only research the effects of supersonic flight on control surfaces and how to counter any problems caused by high speed on manuverability. The D-558-2 reached Mach 1.88 and 74,000 feet in its first series of tests, flown by Douglas test pilot Bill Bridgeman; afterwards, most test flights were either undertaken by US Marine Corps test pilot Lieutenant Colonel Marion Carl (one of the highest-ranked Marine aces of World War II) or NACA’s chief test pilot, Scott Crossfield.
The test program was very successful, discovering many of the difficulties that future pilots would encounter in supersonic environments, and how aircraft designers could plan and rectify these problems. Some Skyrocket flights were flown with dummy drop tanks and bombs to test how ordnance would react at high speed; others had different wing additions, such as leading-edge extensions, slats, movable stabilizers and wing fences, to best learn the effects of supersonic airflow over wings. Only reluctantly did NACA allow the test pilots to try and set speed records, preferring to leave that to the X-1 program and the USAF, but eventually relented. Crossfield took the D-558-2 over Mach 2 on 20 November 1953, the first person to do so.
The D-558-2 program ended in August 1956, after over a thousand flights without a single accident. All three aircraft were preserved for museums, where they remain today.
Bureau Number 37975, with the civil registration N7914C, was the third and final Skyrocket built, and was built from the start with mixed jet/rocket propulsion. 37975 was used mostly to test stability and the ability to recover from the nose pitching up at supersonic speeds. The wing was modified several times with fences, slats, and leading edge extensions. Crossfield flew the aircraft, along with Bridgeman and Walter Jones. It was retired in 1955 and donated to Antelope Valley College, at Lancaster, California--not far from Edwards AFB, where the testing of the Skyrocket had taken place.
Though it could stand a coat of paint, 37975 is attractively displayed on the college grounds. We visited on a pleasant California evening in May 2021.
Douglas D-558-2 Skyrocket
Following the end of World War II, the United States began a program of studying supersonic flight, with the program being run in conjunction with the National Advisory Committee for Aeronautics, the US Navy, and the US Army Air Force (soon to become the US Air Force). While Bell Aircraft built the X-1 for supersonic flight, Douglas worked on the D-558 series with much the same purpose. The company began with the D-558-1 Skystreak, which was intended to study both jet propulsion and supersonic speeds; the X-1 broke the sound barrier first, and the Skystreak, while providing valuable research on near-supersonic speeds and handling, could only reach the very beginning of supersonic speed in a dive.
Douglas had intended to equip the D-558-1 with a mixed jet/rocket propulsion, but the fuselage was too narrow. As work began to rectify this problem, Douglas’ designers learned of wartime German research into swept wings for better handling at high speeds. The Skystreak was completely redesigned into the swept-wing, larger D-558-2 Skyrocket. To test the aircraft, the first of three D-558-2s was equipped with only a jet engine, and first flew in February 1948, with rocket propulsion to be added later.
The D-558-2 was intended to only research the effects of supersonic flight on control surfaces and how to counter any problems caused by high speed on manuverability. The D-558-2 reached Mach 1.88 and 74,000 feet in its first series of tests, flown by Douglas test pilot Bill Bridgeman; afterwards, most test flights were either undertaken by US Marine Corps test pilot Lieutenant Colonel Marion Carl (one of the highest-ranked Marine aces of World War II) or NACA’s chief test pilot, Scott Crossfield.
The test program was very successful, discovering many of the difficulties that future pilots would encounter in supersonic environments, and how aircraft designers could plan and rectify these problems. Some Skyrocket flights were flown with dummy drop tanks and bombs to test how ordnance would react at high speed; others had different wing additions, such as leading-edge extensions, slats, movable stabilizers and wing fences, to best learn the effects of supersonic airflow over wings. Only reluctantly did NACA allow the test pilots to try and set speed records, preferring to leave that to the X-1 program and the USAF, but eventually relented. Crossfield took the D-558-2 over Mach 2 on 20 November 1953, the first person to do so.
The D-558-2 program ended in August 1956, after over a thousand flights without a single accident. All three aircraft were preserved for museums, where they remain today.
Bureau Number 37975, with the civil registration N7914C, was the third and final Skyrocket built, and was built from the start with mixed jet/rocket propulsion. 37975 was used mostly to test stability and the ability to recover from the nose pitching up at supersonic speeds. The wing was modified several times with fences, slats, and leading edge extensions. Crossfield flew the aircraft, along with Bridgeman and Walter Jones. It was retired in 1955 and donated to Antelope Valley College, at Lancaster, California--not far from Edwards AFB, where the testing of the Skyrocket had taken place.
Though it could stand a coat of paint, 37975 is attractively displayed on the college grounds. We visited on a pleasant California evening in May 2021.