Tag Archives: Test Flight

4 May 1927

Spirit of St. Louis over San Diego, May 1927. (San Diego Air and Space Museum)

4 May 1927: Charles A. Lindbergh completes his last series of flight tests of the Ryan NYP, N-X-211, Spirit of St. Louis. Flying at 50 feet (15.2 meters) over San Diego Bay, he times the Spirit‘s flight from marker to marker with a stop watch. The airspeed indicator jumps past 130 miles per hour (209.2 kilometers per hour). He records indicated air speed and engine r.p.m. at various power settings. At 1,500 r.p.m. the Spirit can fly at 96 miles per hour (154.5 kilometers per hour). He makes three runs in each direction to come up with averages.

After the speed runs, Lindbergh flies back to Camp Kearney for load tests. Take-off distances are measured while increasing the fuel load in 50 gallon (189.3 liter) increments.

Twilight is thickening. We stake the Spirit of St. Louis down and leave it under guard. . . When I get back to the city, I telegraph my partners that the tests are satisfactorily completed. . . .

The Spirit of St. Louis, by Charles A. Lindbergh, Charles Scribner’s Sons, 1953, Chapter 37 at Page 128.

© 2016, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

28 April 1927

Charles Lindbergh watches as the Spirit of St. Louis is towed from the Ryan factory to Dutch Flats for testing. (Donald A. Hall Collection)
Charles Lindbergh watches as the Spirit of St. Louis is towed from the Ryan factory to Dutch Flats for testing. (Donald A. Hall Collection)

“This morning I’m going to test the Spirit of St. Louis. It’s the 28th of April — just over two months since I placed our order with the Ryan Company. . . Today, reality will check the claims of formula and theory on a scale which hope can’t stretch a single hair. Today, the reputation of the designing engineer, of the mechanics, in fact of every man who’s had a hand in building the Spirit of St. Louis, is at stake. And I’m on trial too, for quick action on my part may counteract an error by someone else, or a faulty move may bring a washout crash.”

The Spirit of St. Louis, by Charles A. Lindbergh,Charles Scribner’s and Sons, 1953, Chapter 35 at Page 120.

Ryan NYP N-X-211, Spirit of St. Louis, front view, at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Collection)
Ryan NYP N-X-211, Spirit of St. Louis, front view, at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Collection)
The Ryan NYP N-X-211, Spirit of St. Louis, right front quarter view, at Dutch Flats, San Diego, California. (Donald A. Hall Collection)
The Ryan NYP N-X-211, Spirit of St. Louis, right front quarter view, at Dutch Flats, San Diego, California. (Donald A. Hall Collection)
Ryan NYP N-X-211, Spirit of St. Louis, right side view, at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Collection)
Ryan NYP N-X-211, Spirit of St. Louis, right profile, at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Collection)

The Ryan NYP, registration N-X-211, has been towed from the Ryan Airlines Company factory in San Diego, California, to nearby Dutch Flats for its first test flight. Air Mail pilot Charles A. Lindbergh, representing a syndicate of St. Louis businessmen, has contracted with Ryan to build a single-engine monoplane designed for one man to fly non-stop across the Atlantic Ocean, from New York to Paris.

“I signal chocks away. . . and open the throttle. . . I’ve never felt an airplane accelerate so fast before. The tires are off the ground before they roll a hundred yards. . . .”

And the rest is History.

Spirit of St. Louis takes to the air for the first time at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Collection)
Spirit of St. Louis takes to the air for the first time at Dutch Flats, San Diego, California, 28 April 1927. (Donald A. Hall Collection)

© 2016, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

20 March 1945

Tony LeVier and the first prototype Lockheed XP-80A, 44-83021, in flight over southern California’s high desert, 1945. (Lockheed Martin)
Anthony W. (“Tony”) LeVier

20 March 1945: Tony LeVier was conducting a test flight of the first prototype Lockheed XP-80A, 44-83021, near Muroc Army Air Field (now known as Edwards Air Force Base).

The XP-80A was developed from the original XP-80 prototype, but was larger to incorporate a more powerful General Electric I-40 turbojet engine in place of the original Allis-Chalmers J36 (a license-built version of the British Halford H.1B). The I-40 was a single-shaft turbojet which used a double-inlet, single-stage, centrifugal-flow compressor, fourteen straight-through combustors and a single-stage axial-flow turbine. The engine had a maximum speed of 11,500 r.p.m. and produced 4,000 pounds of thrust (17.79 kilonewtons). The I-40 was 48 inches (1.2 meters) in diameter and weighed 1,820 pounds (826 kilograms). The I-40 would be produced by Allison as the J33-series.

General Electric I-40 turbojet engine cross section. (NASA)

At 15,000 feet (4,572 meters), LeVier put the XP-80A into a dive, intending to level off at 10,000 feet (3,048 meters) for a high-speed run. However, at 11,000 feet (3,353 meters), the single-stage axial-flow turbine inside the jet engine failed and fragments tore through the prototype’s fuselage. The tail section of the airplane was cut off and the XP-80A went out of control.

An example of a turbine failure in a Lockheed P-80. (San Diego Air and Space Museum)

The XP-80A was not equipped with an ejection seat and LeVier had difficulty getting out, but finally escaped at about 4,000 feet (1,219 meters).

44-83021 crashed near the town of Rosamond and was completely destroyed. Tony LeVier’s parachute was swinging and he was severely injured when he hit the ground. His injuries kept him from flying for the next six months.

Lockheed XP-80A 44-83021 (U.S. Air Force)
Lockheed XP-80A 44-83021 (U.S. Air Force)

The Lockheed XP-80A was a single-place, single engine prototype fighter. It was 34 feet, 6 inches (10.516 meters) long with a wingspan of 39 feet, 0 inches (11.887 meters) and overall height of 11 feet, 4 inches (3.454 meters). It had an empty weight of 7,225 pounds (3,277 kilograms) and gross weight of 9,600 pounds (4,354 kilograms).

Armament consisted of six Browning .50-caliber AN-M2 (12.7 × 99 NATO) machine guns with 300 rounds of ammunition per gun.

Two XP-80As were built. These were followed by twelve YP-80A Shooting Star service test aircraft. The Lockheed P-80A Shooting Star was ordered into production with an initial contract for 500 aircraft. This was soon followed by a second order for 2,500 fighters.

Wreckage of XP-80A 44-83021 loaded on a flat bed trailer. (U.S. Air Force)
Wreckage of XP-80A 44-83021 loaded on a flat bed trailer. (U.S. Air Force)

© 2017, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

10 January 1964

Boeing B-52H-170-BW 61-023
Boeing B-52H-170-BW Stratofortress 61-023. (U.S. Air Force)

10 January 1964: This Boeing B-52H Stratofortress, serial number 61-023, flown by Boeing test pilot Charles F. (“Chuck”) Fisher, was conducting structural testing in turbulence near East Spanish Peak, Colorado. The other crew members were pilots Richard V. Curry and Leo Coer, and navigator James Pittman. Dick Curry was flying the airplane and Chuck Fisher, the aircraft commander, was in the co-pilot’s position. Pittman was on the lower deck.

The bomber was carrying two North American Aviation GAM-77 Hound Dog cruise missiles on pylons under its wings.

The Boeing B-52 Stratofortress had been designed as a very high altitude penetration bomber, but changes in Soviet defensive systems led the Strategic Air Command to change to very low altitude flight as a means of evading radar. This was subjecting the airframes to unexpected stresses. “Ten-Twenty-Three” (its serial number was 61-023, shortened on the vertical fin to “1023”) had been returned to Boeing Wichita by the Air Force to be instrumented to investigate the effects of high-speed, low-altitude flight on the 245-ton bomber.

Flying at 14,300 feet (4,359 meters) and 345 knots (397 miles per hour, 639 kilometers per hour), indicated air speed, the airplane encountered severe clear air turbulence and lost the vertical stabilizer. Several B-52s had been lost under similar circumstances. (Another, a B-52D, was lost just three days later at Savage Mountain, Maryland.)

East Spanish Peak (left), 12,688 feet (3,867 meters) and West Spanish Peak, 13,626 feet (4,153 meters), Sangre de Cristo Mountains, Colorado. (Footwarrior)
East Spanish Peak (left), 12,688 feet (3,867 meters) and West Spanish Peak, 13,626 feet (4,153 meters), Sangre de Cristo Mountains, Colorado. (Footwarrior)
Charles F. Fisher. (Argenta Images)
Charles F. Fisher. (Argenta Images)

Chuck Fisher immediately took control of the B-52. He later reported, “As the encounter progressed, a very sharp-edged blow which was followed by many more. We developed an almost instantaneous rate of roll at fairly high rate. The roll was to the far left and the nose was swinging up and to the right at a rapid rate. During the second portion of the encounter, the airplane motions actually seemed to be negating my control inputs. I had the rudder to the firewall, the column in my lap, and full wheel, and I wasn’t having any luck righting the airplane. In the short period after the turbulence I gave the order to prepare to abandon the airplane because I didn’t think we were going to keep it together.”

A Boeing report on the incident, based on installed sensors and instrumentation aboard -023, said that the bomber had  “. . . flown through an area containing the combined effects of a (wind) rotor associated with a mountain wave and lateral shear due to airflow around a mountain peak. . . Gust initially built up from the right to a maximum of about 45 feet per second [13.7 meters per second] (TAS), then reversed to a maximum of 36 feet per second [11 meters per second] from the left, before swinging to a maximum of about 147 feet per second [44.8 meters per second] from the left followed by a return to 31 feet per second [9.5 meters per second].”

Fisher flew the bomber back to Wichita and was met by a F-100 Super Sabre chase plane. When the extent of the damage was seen, the B-52 was diverted due to the gusty winds in Kansas. Six hours after the damage occurred, Chuck Fisher safely landed the airplane at Eaker Air Force Base, Blythville, Arkansas. He said it was, “the finest airplane I’ve ever flown.”

Boeing B-52H-170-BW Stratofortress 61-023, "Ten-Twenty-Three", after losing the vertical fin, 10 January 1964. (Boeing)
Boeing B-52H-170-BW Stratofortress 61-023, “Ten-Twenty-Three”, after losing the vertical fin, 10 January 1964. (Boeing)

61-023 was repaired and returned to service. It remained active with the United States Air Force until it was placed in storage at Tinker Air Force Base, Oklahoma, 24 July 2008.

Charles F. Fisher and the Boeing test crew with B-52H Stratofortress 61-023. (Boeing)
Charles F. Fisher at left,  and the Boeing test crew with B-52H Stratofortress 61-023. (Boeing)

The B-52H is a sub-sonic, swept wing, long-range strategic bomber. It has a crew of five. The airplane is 159 feet, 4 inches (48.6 meters) long, with a wing span of 185 feet (56.4 meters). It is 40 feet, 8 inches (12.4 meters) high to the top of the vertical fin. Maximum Takeoff Weight (MTOW) is 488,000 pounds (221,353 kilograms).

There are eight Pratt & Whitney TF33-PW-3 turbofan engines mounted in two-engine pods suspended under the wings on four pylons. Each engine produces a maximum of 17,000 pounds of thrust (75.620 kilonewtons). The TF-33 is a two-spool axial-flow turbofan engine with 2 fan stages, 14-stage compressor stages (7 stage intermediate pressure, 7 stage high-pressure) and and 4-stage turbine (1 stage high-pressure, 3-stage low-pressure). The engine is 11 feet, 10 inches (3.607 meters) long, 4 feet, 5.0 inches (1.346 meters) in diameter and weighs 3,900 pounds (15,377 kilograms).

The B-52H can carry approximately 70,000 pounds (31,750 kilograms) of ordnance, including free-fall bombs, precision-guided bombs, thermonuclear bombs and cruise missiles, naval mines and anti-ship missiles.

The bomber’s cruise speed is 520 miles per hour (837 kilometers per hour) and its maximum speed is 650 miles per hour (1,046 kilometers per hour) at 23,800 feet (7,254 meters) at a combat weight of 306,350 pounds. Its service ceiling is 47,700 feet (14,539 meters) at the same combat weight. The unrefueled range is 8,000 miles (12,875 kilometers).

With inflight refueling, the Stratofortress’s range is limited only by the endurance of its five-man crew.

The B-52H is the only version still in service. 102 were built and as of 27 September 2016, 76 are still in service. Beginning in 2013, the Air Force began a fleet-wide technological upgrade for the B-52H, including a digital avionics and communications system, as well as an internal weapons bay upgrade. The bomber is expected to remain in service until 2040.

Boeing B-52H-170-BW Stratofortress 61-023 taxiing at Minot Air Force Base, North Dakota. (Senior Airman Cassandra Jones, U.S. Air Force)
Boeing B-52H-170-BW Stratofortress 61-023 taxiing at Minot Air Force Base, North Dakota. (Senior Airman Cassandra Jones, U.S. Air Force)

© 2016, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

29 December 1941

North American Aviation XP-51 Mustang 41-038 at Langley Field, Virginia, 29 December 1941. (NASA)
North American Aviation XP-51 Mustang 41-038 at Langley Field, Virginia, 29 December 1941. (NASA)

29 December 1941: The first North American Aviation XP-51 fighter prototype, Air Corps serial number 41-038, arrived at the NACA Langley Memorial Aeronautical Laboratory, Langley Field, Hampton, Virginia, for National Advisory Committee on Aeronautics flight testing. This airplane was the fourth production Royal Air Force Mustang Mk.I, identified as AG348 (North American serial number 73-3101).

The test program resulted in an improved aileron design which significantly improved the Mustang’s maneuverability. The new aileron was used on all production models.

North American Aviation XP-51 41-038 at the NACA Langley Memorial Aeronautical Laboratory. (NASA)

41-038 was returned to Wright Field on 2 November 1942. The second XP-51, 41-039, arrived at Langley in March 1943 for continued  testing.

The Mustang Mk.I (NAA Model NA-73) was a single-place, single-engine fighter of all metal construction. It was 32 feet, 3 inches (9.830 meters) long with a wingspan of 37 feet, ½-inch (11.290 meters) and overall height of 12 feet, 2½ inches (3.719 meters). The airplane’s empty weight was 6,280 pounds (25,848.6 kilograms) and loaded weight was 8,400 pounds (3,810.2 kilograms).

North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboratory, right profile. (NASA)

The Mustang Mk.I/XP-51was powered by a liquid-cooled, supercharged 1,710.60-cubic-inch-displacement (28.032 liter) Allison Engineering Company V-1710-F3R (V-1710-39) single overhead cam (SOHC) 60° V-12 engine which turned a 10 foot, 9 inch (3.277 meter) diameter, three-bladed, Curtiss Electric constant-speed propeller through a 2.00:1 gear reduction. The engine had a takeoff rating of 1,150 horsepower at 3,000 r.p.m. at Sea Level with 45.5 inches of manifold pressure (1.51 Bar), and a war emergency rating of 1,490 horsepower with 56 inches of manifold pressure (1.90 Bar).

North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboroatory. (NASA)

The XP-51 tested at Wright Field had a maximum speed of 382.0 miles per hour (614.8 kilometers per hour) at 13,000 feet (3,962 meters) at wide open throttle, and cruise speed of 300 miles per hour (483 kilometers per hour).

Below 20,000 feet (6,096 meters), the Mustang was the fastest fighter in the world. The Mk.I was 30 m.p.h. (48 kilometers per hour) faster than its contemporary, the Curtiss P-40 Warhawk, though both used exactly the same engine. Below 15,000 feet (4,572 meters), the Mustang was also 30–35 m.p.h (48–56 kilometers per hour) faster than a Supermarine Spitfire, which had the more powerful Roll-Royce Merlin V-12.

The service ceiling was 30,800 feet (9,388 meters) and range was 750 miles (1,207 kilometers).

North American Aviation XP-51 41-038 at NACA Langley Memorial Aeronautical Laboratory, rear view. (NASA LMAL 27033)

Armament consisted of two synchronized Browning M2 .50-caliber machine guns mounted in the nose under the engine and firing through the propeller, and two more .50-caliber and four Browning .303 Mk.II machine guns in the wings.

Two Mustang Mk.Is, AG348 and AG354, were taken from the first RAF production order and sent to Wright Field for testing by the U.S. Army Air Force. These airplanes, assigned serial numbers 41-038 and 41-039, were designated XP-51. They would be developed into the legendary P-51 Mustang. In production from 1941 to 1945, a total of 16,766 Mustangs of all variants were built.

North American XP-51 41-038 was transferred to the Smithsonian Institution National Air and Space Museum. It was restored in 1976. It is now in the collection of the EAA AirVenture Museum, Oshkosh, Wisconsin. It has a current FAA registration number, N51NA.

North American Aviation XP-51 41-038 in the collection of the Experimental Aircraft Association AirVenture Museum, Oshkosh, Wisconsin. (EAA AirVenture Museum)
North American Aviation XP-51 41-038 in the collection of the Experimental Aircraft Association AirVenture Museum, Oshkosh, Wisconsin. (EAA AirVenture Museum)

© 2016, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather