Tag Archives: Flight Test

7 August 1951

William Barton Bridgeman. (Boris Artzybasheff/TIME Magazine)

7 August 1951: Douglas Aircraft Company test pilot William Barton Bridgeman flew the rocket-powered U.S. Navy/NACA/Douglas D-558-2 Skyrocket, Bu. No. 37974 (NACA 144), to a record speed of Mach 1.88 (1,245 miles per hour/2,034 kilometers per hour) at Muroc Dry Lake (later Edwards Air Force Base) in the high desert of southern California.

The D-558-2 was airdropped at 34,000 feet (10,363 meters) from a Navy P2B-1S Superfortress, Bu. No. 84029 (a U.S. Air Force Boeing B-29-95-BW Superfortress, 45-21787, transferred to the Navy and heavily modified as a drop ship) flown by another Douglas test pilot, George Jansen.

Douglas D-558-II Skyrocket, Bu. No., 37974, NACA 144, is dropped from the Boeing P2B-1S Superfortress, Bu. No. 84029, NACA 137. (NASA)

In his autobiography, Bridgeman described the flight:

We are at 34,000 feet. My cue. Ten cold minutes preparing the ship for flight. The trap door springs and releases the captive Skyrocket swollen with explosive propellants. She blasts into flight.

Thirty seconds and I am supersonic. Sixty-eight thousand feet and this is it. Over the rim. Easy. The electrically controlled stabilizer flies her now. It takes over for me. At .6 G I push over just enough to get my speed. I am on the ragged edge between .6 G and .8 G. It is working! Everything is going according to my plan. It is so easy this time. Surely I cannot be breaking my last record without having to pay for it. The Machmeter is moving up, fluttering toward the Number 2. . . the rockets sputter and the fuel is gone. That’s all she wrote.

Late that afternoon the official speed attained by the Skyrocket reduced from data and film came out  of the aerodynamicists’ office. Mach 1.88.

The Lonely Sky, William Bridgeman, Castle and Company LTD, London, 1956, Chapter XXII at Page 260.

NACA 144, a Douglas D-558-II Skyrocket, Bu. No. 37974, parked on Muroc Dry Lake. (NACA E-1441)

Bill Bridgeman had been a Naval Aviator during World War II, flying the Consolidated PBY Catalina and PB4Y (B-24) Liberator long range bombers with Bombing Squadron 109 (VB-109), “The Reluctant Raiders.” Bridgeman stayed in the Navy for two years after the end of the war, then he flew for Trans-Pacific Air Lines in the Hawaiian Islands and Southwest Airlines in San Francisco, before joining the Douglas Aircraft Company as a production test pilot. He flew new AD Skyraiders as they came off the assembly line at El Segundo, California. Bridgeman soon was asked to take over test flying the D-558-2 Skyrocket test program at Muroc Air Force Base.

Screen Shot 2016-08-07 at 11.13.14

The D-558-II Skyrocket was Phase II of a planned three phase experimental flight program. It was designed to investigate flight in the transonic and supersonic range. It was 46 feet, 9 inches (14.249 meters) long with a 25 foot (7.62 meter) wing span. The wings were swept back to a 35° angle. The Skyrocket was powered by a Westinghouse J34-WE-40 11-stage axial-flow turbojet engine, producing 3,000 pounds of thrust, and a Reaction Motors LR8-RM-6 four-chamber rocket engine, which produced 6,000 pounds of thrust. The rocket engine burned alcohol and liquid oxygen.

There were three D-558-2 Skyrockets. Between 4 February 1948 and 28 August 1956, they made a total of 313 flights. The Skyrocket flown by Bill Bridgeman to Mach 1.88 is in the collection of the Smithsonian Institution National Air and Space Museum.

NACA 144, a Douglas D-558-II Skyrocket, on display at the National Mall Building, Smithsonian Institution. (NASM)
NACA 144, a Douglas D-558-II Skyrocket, on display at the National Mall Building, Smithsonian Institution. (NASM)

© 2020, Bryan R. Swopes

4 August 1960

4 August 1960: NASA research test pilot Joseph Albert Walker set an unofficial world speed record when he flew the number one North American Aviation X-15, 56-6670, to 2,195 miles per hour (3,532.5 kilometers per hour). This was the 18th flight of the X-15 Program. It was 56-6670’s eighth flight and Walker’s fourth X-15 flight. The purpose of this test was to gradually increase the rocket plane’s speed toward its design limit.

Airdropped from the Boeing NB-52A Stratofortress mothership, 52-003, over Silver Lake, near the California-Nevada border, at 08:59:13.0 a.m., PDT, Walker fired the X-15’s two Reaction Motors XLR11-RM-13 rocket engines for 264.2 seconds. The X-15 accelerated to Mach 3.31 and climbed to a peak altitude of 78,112 feet (23,810 meters). [The two XLR11s were used as an interim powerplant until the Reaction Motors XLR99 was ready. The combined thrust of both LR11s was only slightly more than the idle thrust of the XLR99.]

Walker touched down on Rogers Dry Lake at Edwards Air Force Base, California, after a flight of 10 minutes, 22.6 seconds.

Joe Walker with X-15 56-6670 on Rogers Dry Lake. (NASA)

© 2016, Bryan R. Swopes

3 August 1972

McDonnell Douglas YF-15A-1-MC Eagle, 71-0280, with McDonnell Douglas RF-4C Phantom II chase plane, in flight near Edwards AFB. (U.S. Air Force)

3 August 1972: During a 45-minute test flight at Edwards Air Force Base, the McDonnell Douglas YF-15A-1-MC Eagle prototype, 71-0280, went supersonic for the first time, reaching Mach 1.5.

An air-superiority fighter, the F-15 entered service with the United States Air Force in 1975. More than 1,500 fighter, two-seat trainer, and two-seat F-15E Strike Eagle fighter-bombers have been built by McDonnell Douglas and Mitsubishi. It is operated by allied air forces around the world and is expected to remain in front line service until 2025.

McDonnell Douglas F-15C Eagle. (Defense Media Network)

© 2015, Bryan R. Swopes

1 August 1939

The flight crew of the FAI World Altitude Record-setting Boeing Y1B-17A. Left to right: Captain Pearl H. Robey, Captain Clarence S. Irvine and R. Swofford. (FAI)

1 August 1939: Captains Clarence S. Irvine and Pearl H. Robey, United States Army Air Corps, used the Boeing Y1B-17A Flying Fortress (Model 299F), serial number 37-369, to set a Fédération Aéronautique Internationale (FAI) World Record for Altitude with a 5,000 Kilogram Payload. The bomber climbed to 10,371 meters (34,026 feet) with a payload of 11,023 pounds.¹ ²

On the same day, Irvine and Robey flew the Y1B-17 from Dayton, Ohio to St. Jacob, Illinois, setting an FAI World Record for Speed Over 1,000 Kilometers with a 5,000 Kilogram Payload, averaging 417.46 kilometers per hour (259.40 miles per hour).³

The flight crew of the FAI World Speed Record-setting Boeing Y1B-17A. Left to Right: Capatain C.J. Crane, P.G. Miller, Captain Clarence S. Irvine and Captain pearl H. Robey. (FAI)
The flight crew of the FAI World Speed Record-setting Boeing Y1B-17A. Left to Right: Captain Carl J. Crane, P.G. Miller, Captain Clarence S. Irvine and Captain Pearl H. Robey. (FAI)

The single Y1B-17A (Boeing Model 299F) was originally ordered as a static test article, but when that was determined to be unnecessary, it was used as an engine test aircraft. It was equipped with four 1,823.129-cubic-inch-displacement (29.875 liter) air-cooled, supercharged, Wright R-1820-51 (Cyclone G59) single-row nine-cylinder radial engines. Moss/General Electric turbo-superchargers were installed, initially on top of the wings, but were moved to the bottom of the engine nacelles.

Boeing Y1B-17A 37-369. (FAI)

The supercharged Wright R-1820-39 (Cyclone R-1820-G5) engines of the YB-17s were rated at 805 horsepower at 2,100 r.p.m., at Sea Level, 775 horsepower at 14,000 feet (4,267 meters), and 930 horsepower at 2,200 r.p.m., for take off. By contrast, the YB-17A’s R-1820-51 engines were rated at 800 horsepower at 2,100 r.p.m. at Sea Level, and 1,000 horsepower at 2,200 r.p.m. for take off. But the turbochargers allowed the engines to maintain their Sea Level power rating all the way to 25,000 feet (7,620 meters). Both the -39 and -51 engine had a 16:11 propeller gear reduction ratio. The R-1820-51 was 3 feet, 9.06 inches (1.145 meters) long, 4 feet, 6.12 inches (1.375 meters) in diameter, and weighed 1,200.50 pounds (544.54 kilograms). 259 were produced by Wright between September 1937 and February 1940.

Boeing Y1B-17A 37-369. (U.S. Air Force)

The turbo-superchargers installed on the YB-17A greatly improved the performance of the bomber, giving it a 55 mile per hour (89 kilometer per hour) increase in speed over the supercharged YB-17s, and increasing the bomber’s service ceiling by 7,000 feet (2,132 meters). The turbo-superchargers worked so well that they were standard on all following B-17 production models.

Boeing Y1B-17A 37-369. (U.S. Air Force photo)

The Boeing Y1B-17A was 68 feet, 9 inches (20.955 meters) long with a wingspan of 103 feet, 9–3/8 inches (31.633 meters) and height of 14 feet, 11–5/16 inches (4.363 meters). Its empty weight was 26,520 pounds (12,029 kilograms). The maximum gross weight was 45,650 pounds (20,707 kilograms)

The Model 299F had a cruise speed of 230 miles per hour (370 kilometers per hour), a maximum speed of 271 miles per hour (436 kilometers per hour) at Sea Level and 295 miles per hour (475 kilometers per hour) at 25,000 feet (7,620 meters). The service ceiling was 38,000 feet (11,582 meters). The maximum range was 3,600 miles (5,794 kilometers). Carrying a 4,000 pound (1,814 kilogram) load of bombs, the range was 2,400 miles (3,862 kilometers).

The Y1B-17A could carry eight 600 pound (272 kilogram) bombs in an internal bomb bay. Defensive armament consisted of five .30-caliber machine guns.

Following the engine tests, 37-369 was re-designated B-17A.

The Boeing Y1B-17A in flight near Mt. Rainier on 28 February 1938. (U.S. Air Force)

¹ FAI Record File Number 8318

² This record-setting flight was dramatized in the motion picture “Test Pilot,” (1938, Metro-Goldwyn-Mayer) with Clark Gable, Spencer Tracy and Myrna Loy. This movie is now 80 years old and has a melodramatic plot, but is well worth seeing for aviation history enthusiasts.

³ FAI Record File Number 10443

© 2018, Bryan R. Swopes

23 July 1970

McDonnell Douglas DC-10 rollout at Long Beach, 23 July 1970. (Boeing)

23 July 1970: At Long Beach, California, the first McDonnell Douglas DC-10 airliner was rolled out. A DC-10-10, serial number 46500 with FAA registration N10DC, this aircraft was used for flight testing and Federal Aviation Administration certification. It made 989 test flights, accumulating 1,551 flight hours. It was put into commercial service with American Airlines 12 August 1972, re-registered as N101AA.

The DC-10 was a wide-body commercial airliner designed for medium to long range flights. It was flown by a crew of three and depending on the cabin arrangement, carried between 202 and 390 passengers. The DC-10-10 was 170 feet, 6 inches (51.968 meters) long with a wingspan of 155 feet, 4 inches (47.346 meters) and overall height of 58 feet, 1 inch (17.704 meters). The airliner had an empty weight of 240,171 pounds (108,940 kilograms) and maximum takeoff weight of 430,000 pounds (195,045 kilograms). It was powered by three General Electric CF6-6D turbofan engines, producing 40,000 pounds of thrust, each. These gave the DC-10 a maximum cruise speed of Mach 0.88 (610 miles per hour, 982 kilometers per hour). Its range is 3,800 miles (6,116 kilometers) and the service ceiling is 42,000 feet (12,802 meters).

In production from 1970 to 1988, a total of 386 DC-10s were built in passenger and freighter versions. 122 were the DC-10-10 variant. Another 60 KC-10A Extender air refueling tankers were built for the U.S. Air Force and 2 KDC-10 tankers for the Royal Netherlands Air Force.

The first McDonnell Douglas DC-10 was in service with American Airlines from 12 August 1972 to 15 November 1994 when it was withdrawn from service and placed in storage at Tulsa, Oklahoma. The 24-year-old airliner had accumulated 63,325 flight hours.

After three years in storage, the first DC-10 returned to service flying for Federal Express. In 1998 it was modernized as an MD-10 and re-registered again, this time as N530FE. It was finally retired from service and scrapped at Goodyear, Arizona in 2002.

© 2015, Bryan R. Swopes