Tag Archives: Flight Test

9 November 1962

McKAY, John B. (Jack) with X-15 56-6672, 13 March 19649 November 1962: Flight 74 of the X-15 Program was the Number Two aircraft’s 31st flight. X-15 56-6671 was carried aloft by Balls 8, the Boeing NB-52B Stratofortress, 53-008, for launch over Mud Lake, Nevada. NASA test pilot John Barron (“Jack”) McKay was to take the rocketplane to 125,000 feet at Mach 5.5 to investigate the stability and handling of the X-15 with the lower half of the ventral fin removed, and to investigate aerodynamic boundary layer phenomena.

North American Aviation X-15 56-6671 under the right wing of a B-52 Stratofortress at 45,000 feet. (NASA)
North American Aviation X-15 56-6671 under the right wing of a B-52 Stratofortress at 45,000 feet. (NASA)

The B-52 mothership dropped Jack McKay and the X-15 right on schedule at 10:23:07.0 a.m., local time, from an altitude of 45,000 feet (13,716 meters) and speed of approximately 450 knots (833 kilometers per hour). McKay advanced the throttle to ignite the Reaction Motors XLR99-RM-1 rocket engine. It fired immediately but when McKay advanced the throttle for the full 57,000 pounds of thrust, the engine remained at just 30%.

The X-15 could have flown back to Edwards Air Force Base, about 200 miles (320 kilometers) to the south, but with the engine not responding to the throttle, it was uncertain that it would continue running. The decision was made to make an emergency landing at Mud Lake.

Having reached a peak altitude of 53,950 feet (16,444 meters) and Mach 1.49 (1,109 miles per hour/1,785 kilometers per hour), Jack McKay continued to circle the lake burning off propellants as he lost altitude. The engine was shut down at 70.5 seconds. McKay positioned the aircraft for landing as he continued to dump unused propellant and liquid oxygen, but a considerable amount remained on board.

As he neared touchdown, he tried to lower the flaps but they did not deploy. The X-15 touched down on the dry lake bed at 296 miles per hour (476.4 kilometers per hour), 66 miles per hour (106 kilometers per hour) faster than normal.

Duration of the flight from air launch to touchdown was 6 minutes, 31.1 seconds.

The high speed and extra weight caused the X-15’s rear skids to hit harder than normal. When the nose wheels hit, a rebound effect placed even higher loads on the rear struts. At the same time, with the elevators in an extreme nose-up position, the higher aerodynamic loads pushed the skids deeper into the lake bed. This higher loading caused the left rear strut to collapse. The X-15 rolled to the left and the left elevator dug into the lake bed. This caused the aircraft to start sliding to the left. Jack McKay jettisoned the canopy and as the right wing tip dug into the surface, the X-15 flipped over and came to rest upside down.

A Piasecki H-21 rescue helicopter lands near the overturned X-15 at Mud Lake, 9 November 1961. (NASA)
A Piasecki H-21 rescue helicopter lands near the overturned X-15 at Mud Lake, 9 November 1961. (NASA)
The X-15 rolled over when the left landing skid collapsed because of the high-speed, overweight emergency landing at Mud Lake, Nevada. Jack McKay was trapped in the cockpit and suffered serious spinal injuries. (NASA)
The X-15 rolled over when the left landing skid collapsed because of the high-speed, overweight emergency landing at Mud Lake, Nevada. Jack McKay was trapped in the cockpit and suffered serious spinal injuries. (NASA)
The Number Two X-15, 56-6671, lies upside down and severely damaged at Mud Lake, Nevada, 9 November 1962. (NASA)
The Number Two X-15, 56-6671, lies upside down and severely damaged at Mud Lake, Nevada, 9 November 1962. (NASA)

McKay was seriously injured. He was trapped in the upside down X-15 and was in danger from the vapors of the ammonia propellants and liquid oxygen. An H-21 rescue helicopter hovered overhead to blow the vapor away.

Prior to the flight, an Air Force C-130 had brought a fire engine and crew to standby at Mud Lake, returned to Edwards and picked up a second fire engine and its crew, then remained airborne should an emergency landing be made at another intermediate dry lake.

These propositioned emergency assets were able to rescue McKay and to transport him to the hospital back at Edwards.

McKay eventually recovered sufficiently to return to flight status, but ultimately his injuries forced him to retire.

The Number Two X-15 was severely damaged. It was taken back to North American and was rebuilt into the X-15A-2, intended to reach speeds up to Mach 8. It would be more than a year and a half before it flew again.

North American Aviation X-15A-2 56-6671, after a 19-month repair, redesign and modification program. The fuselage was lengthened, additional propellant and reaction control tanks installed internally, the nose wheel and rear landing skid struts lengthened, and external tanks installed. (NASA)
North American Aviation X-15A-2 56-6671, after a 19-month repair, redesign and modification program. The fuselage was lengthened, additional propellant and reaction control tanks installed internally, the nose wheel and rear landing skid struts lengthened, and external tanks installed. (NASA)

© 2016, Bryan R. Swopes

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5 November 1959

The Number 2 X-15, 56-6671, broke in half when it made an emergency landing while still partially loaded with propellants. (NASA)
The Number 2 X-15, 56-6671, broke in half when it made an emergency landing while still partially loaded with propellants. (NASA)

5 November 1959: During his fourth X-15 flight—the third in the Number Two ship, 56-6671—North American Aviation chief test pilot Albert Scott Crossfield made an emergency landing at Rosamond Dry Lake after one of the two Reaction Motors XLR11-RM-13 rocket engines exploded, causing an engine compartment fire.

The X-15 had been launched by the Boeing NB-52A Stratofortress, 52-003, at 0.82 Mach and approximately 45,000 feet (13,716 meters) over Bouquet Canyon Reservoir, about 35 miles (56 kilometers) southwest of Edwards Air Force Base. Scott Crossfield ignited both XLR11 rocket engines and began to accelerate and climb, but one of four combustion chambers of the lower engine exploded almost immediately. He shut both engines down after 11.7 seconds. Crossfield kept the rocketplane in a level attitude for the 114 seconds it took to jettison the liquid oxygen and water-alcohol propellants to lighten the X-15 for the landing. The tanks could not fully drain and the aircraft remained approximately 1,000 pounds (455 kilograms) overweight.

The X-15 approached the emergency landing site at Rosamond Dry Lake, about ten miles (16 kilometers) southwest of Edwards, while Major Robert M. White, flying a Lockheed F-104 chase plane, called out Crossfield’s distance from the dry lake and his altitude. As he neared the touch down point, Crossfield raised the X-15’s nose to decelerate.

“I lowered the skids and nose wheel, pulled the flaps, and felt for the lake bed.

“The skids dug in gently. The nose wheel slammed down hard and the ship plowed across the desert floor, slowing much faster than usual. Then she came to a complete stop within 1500 feet instead of the usual 5000 feet. Something was wrong; the skids failed, I was sure. . . Quickly I scrambled out of the cockpit. What I saw almost broke my heart. The fuselage had buckled immediately aft of the cockpit, two hundred and thirty inches back from the nose. Her belly had dragged in the sand, causing the abrupt deceleration on the lake. The rocket chambers which had exploded at launch were a shambles.”

Always Another Dawn: The Story of a Rocket Test Pilot, by A. Scott Crossfield and Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960, Chapter 41 at Pages 383–384.

The scene at Rosamond Dry Lake after Scott Crossfield's emergency landing after an engine explosion. (NASA)
The scene at Rosamond Dry Lake after Scott Crossfield’s emergency landing following an engine explosion. (NASA)

It was determined that the engine had exploded due to an ignition failure, a relatively simple problem not connected to the design of the X-15. But there remained the question as to why the rocketplane had broken in half. The investigation found that the rapid extension of the nose wheel strut when lowered caused the oil inside the strut to foam and vaporize, providing almost no shock absorption. This was corrected and the check list changed to lower the gear sooner.

The total duration of this flight was 5 minutes, 28.0 seconds. The peak altitude was 45,462 feet (13,857 meters) and the maximum speed was 660 miles per hour (1,062 kilometers per hour).

56-6671 was taken back to the North American Aviation plant for repair. It returned to flight operations three months later.

Test pilot A. Scott Crossfield with the damaged X-15 (UPI/Harry Ransom Center
Test pilot A. Scott Crossfield with the damaged X-15 on Rosamond Dry Lake. (UPI/Harry Ransom Center, University of Texas at Austin)

© 2016, Bryan R. Swopes

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3 November 1965

North American Aviation X-15A-2 56-6671 on Rogers Dry Lake. In addition to the lengthened fuselage and external tanks, the nose wheel strut is longer and the windshields have been changed to an oval shape. A wheeled dolly supports the aft end of the rocketplane. (NASA)
North American Aviation X-15A-2 56-6671 on Rogers Dry Lake. In addition to the lengthened fuselage and external tanks, the nose wheel strut is longer and the windshields have been changed to an oval shape. A wheeled dolly supports the aft end of the rocketplane. (NASA)

3 November 1965: Major Robert A. Rushworth made the first flight of the modified X-15A-2 rocketplane, Air Force serial number 56-6671. After a landing accident which caused significant damage to the Number 2 X-15, it was rebuilt by North American Aviation. A 28-inch (0.71 meter) “plug” was installed in the fuselage forward of the wings to create space for a liquid hydrogen fuel tank which would be used for an experimental “scramjet” engine that would be mounted on the the ventral fin. The modified aircraft was also able to carry two external fuel tanks. It was hoped that additional propellant would allow the X-15A-2 to reach much higher speeds.

The first flight with the new configuration was an “envelope expansion” flight, intended to test the handling characteristics of the X-15A-2, and to jettison the tanks (which were empty on this flight) to evaluate the separation and trajectory as they fell away from the rocketplane in supersonic flight.

Boeing NB-52A Stratofortress 52-003, The High and Mighty One, with North American Aviation X-15A-2 56-6671 mounted to the pylon under its right wing. The external propellant tanks have been brightly painted to aid tracking after they are jettisoned. (U.S. Air Force)
Boeing NB-52A Stratofortress 52-003, The High and Mighty One, with North American Aviation X-15A-2 56-6671 mounted to the pylon under its right wing. The external propellant tanks have been brightly painted to aid tracking after they are jettisoned. (U.S. Air Force)

The X-15A-2 was dropped from the Boeing NB-52A Stratofortress 52-003, over Cuddeback Lake, 37 miles (60 kilometers) northeast of Edwards Air Force Base in the Mojave Desert of southern California. This was the only time during the 199-flight X-15 Program that this lake was used as a launch point.

The X-15 was released at 09:09:10.7 a.m., PST. Bob Rushworth ignited the Reaction Motors XLR99-RM-1 rocket engine and it ran for 84.1 seconds before its fuel supply was exhausted. This engine was rated at 57,000 pounds of thrust (253.549 kilonewtons).

The X-15 climbed to 70,600 feet (21,519 meters) and reached Mach 2.31 (1,514 miles per hour/2,437 kilometers per hour.)

The test flight went well. The external tanks jettisoned cleanly and fell away. The recovery parachute for the liquid oxygen tank did not deploy, however, and the tank was damaged beyond repair.

Rushworth and the X-15A-2 touched down on Rogers Dry Lake after a flight of 5 minutes, 1.6 seconds.

© 2016, Bryan R. Swopes

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21 October 1959

Gerald Huelsbeck
Gerald Huelsbeck

21 October 1959: McDonnell Aircraft Corporation test pilot Gerald (“Zeke”) Huelsbeck was killed while test flying the first prototype YF4H-1 Phantom II, Bureau of Aeronautics serial number (“Bu. No.”) 142259.

The McDonnell YF4H-1 Phantom II, Bu. No. 142259, takes off at Edwards Air Force Base during preparations for Operation Top Flight. (McDonnell Aircraft Corporation)
McDonnell YF4H-1 Phantom II Bu. No. 142259 takes off at Edwards Air Force Base during preparations for Operation Top Flight. (McDonnell Aircraft Corporation)

In October 1959 the Navy tried, a bit prematurely, for its first world record with the F4H. McDonnell test pilot Gerald “Zeke” Huelsbeck, flying near Edwards AFB, was testing various flight plans for a high-altitude zoom, looking for one to recommend to the Navy test pilot who would fly the record attempt. Huelsbeck was flying the very first F4H prototype when an engine access door blew loose, flames shot through the engine compartment, and the F4H crashed, killing Huelsbeck. (Over the next three years of the F4H-1 test program three aircraft were destroyed and three crew members died, all preparing for record flights.)

Engineering the F-4 Phantom II: Parts Into Systems by Glenn E. Bugos, Naval Institute Press, Annapolis, Maryland, 1996, Chapter 5 at Page 101.

Gerald Huelsbeck
Test Pilot Gerald Huelsbeck with a prototype McDonnell YF4H-1 Phantom II. Huelsbeck is wearing a Goodyear Mk. IV full-pressure suit. (McDonnell Aircraft Corporation)

The flight control system of the YF4H-1 was damaged by the fire and went it out of control at high speed and into a spin. Zeke Huelsbeck did eject but was too low. His parachute did not open. The prototype crashed in an open area near Mt. Pinos in the Los Padres National Forest,  Ventura County, California, about 70 miles (113 kilometers) southwest of Edwards.

McDonnell YF4H-1 Bu. No. 142259 was the first prototype Phantom II. It had first been flown by Robert C. Little at Lambert Field, St. Louis, Missouri, 27 May 1958. The Phantom II was designed as a supersonic, high-altitude fleet defense interceptor for the United States Navy. It was a two-place twin engine jet fighter armed with radar- and infrared-homing air-to-air missiles.

Gerald Huelsbeck was born in Wisconsin, 16 April 1928, the third child of Walter Andrew Huelsbeck, a farmer, and Irene M. Voigt Huelsbeck. He attended Carroll College (now, Carroll University) in Waukesha, before joining the United States Navy as a midshipman. He completed flight training at NAS Whiting Field, Florida, and was commissioned as an ensign, 2 June 1950.

In 1950, Ensign Gerald Huelsbeck married Miss Mary Jean Hillary, who had also attended Carroll College. They would have two children.

Huelsbeck was promoted to lieutenant (junior grade), 2 June 1952. Assigned as a fighter pilot during the Korean War, he flew 54 combat missions in the McDonnell F2H Banshee.

While flying in the Navy, Huelsbeck experimented with helmet-mounted cine cameras:

. . . He took a standard gun camera, added a couple of gadgets, and attached it to his helmet, The camera is electrically driven and able to take about two minutes of film with a 50-foot magazine. . . “I spent some time doing ‘hand camera’ work in Korea,” he recalls. “You know, after 54 combat missions, you don’t like to think about crashing while trying to take a picture.”

The Indianapolis Star, Vol. 53, No. 116, Tuesday, 29 September 1955, Page 4 at Columns 2–4

Lt. (j.g.) Huelsbeck in teh cocpit of a Grumman F9F. A small motion picture camera is attached to his flight helmet (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Lt. (j.g.) Huelsbeck in the cockpit of a U.S. Navy fighter. A small motion picture camera is attached to his flight helmet. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

He was serving with VF-11 at NAS Jacksonville, Florida, when he was selected for the United States Naval Test Pilot School at NAS Patuxent River, Maryland, in July 1953.

“Zeke” Huelsbeck left the Navy in 1955 to accept a position as a test pilot with the McDonnell Aircraft Corporation, St. Louis, Missouri. After several months, he was assigned as an experimental test pilot and project pilot of the F4H program.

At the time of the accident, Zeke Huelsbeck was the most experienced pilot flying the F4H.

Gerald Huelsbeck was 31 years old when he died. He is buried in New Berlin, Wisconsin.

McDonnell YF4H-1 Phantom II, Bu. No. 142259, at Lambert Field, St. Louis. (McDonnell Aircraft Corporations)
McDonnell YF4H-1 Phantom II, Bu. No. 142259, at Lambert Field, St. Louis. (McDonnell Aircraft Corporations)

© 2016, Bryan R. Swopes

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20 October 1952

Douglas X-3 (NASA)
Douglas X-3 49-2892. Rogers Dry Lake is in the background. (NASA)

20 October 1952: At Edwards Air Force Base, California, Douglas Aircraft Company test pilot William Barton (“Bill”) Bridgeman made the first test flight of the X-3 twin-engine supersonic research airplane. During a high-speed taxi test five days earlier, Bridgeman and the X-3 had briefly been airborne for approximately one mile over the dry lake bed, but on this flight he spent approximately 20 minutes familiarizing himself with the new airplane.

William Barton “Bill” Bridgeman, 1916–1968. (LIFE Magazine)

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 war, then he flew for Trans-Pacific Air Lines in the Hawaiian Islands and Southwest Airlines in San Francisco, before joining Douglas Aircraft Co. as a production test pilot. He checked out new AD Skyraiders as they came off the assembly line at El Segundo, California. He soon was asked to take over test flying the D-558-2 Skyrocket test program at Muroc Air Force Base (now, Edwards AFB.) With the Skyrocket, he flew higher—79,494 feet (24,230 meters)—and faster—Mach 1.88—than any pilot had up to that time.

Douglas X-3 parked on Rogers Dry Lake, 1956 (NASA)
Douglas X-3 parked on Rogers Dry Lake, 1956 (NASA)

The Douglas X-3, serial number 49-2892, was built for the Air Force and NACA to explore flight in the Mach 1 to Mach 2 range. It was radically shaped, with a needle-sharp nose, very long thin fuselage and small straight wings. The X-3 was 66 feet, 9 inches (20.345 meters) long, with a wing span of just 22 feet, 8.25 inches (6.915 meters). The overall height was 12 feet, 6.3 inches (3.818 meters). The X-3 had an empty weight of 16,120 pounds (7,312 kilograms) and maximum takeoff weight of 23,840 pounds (10,814 kilograms).

It was to have been powered by two Westinghouse J46 engines, but when those were unsatisfactory, two Westinghouse XJ34-WE-17 engines were substituted. This was an axial flow turbojet with an 11-stage compressor and 2-stage turbine. It was rated at 3,370 pounds (14.99 kilonewtons) of thrust, and 4,900 pounds (21.80 kilonewtons) with afterburner. The XJ34-WE-17 was 14 feet, 9.0 inches (4.496 meters) long, 2 feet, 1.0 inch (0.635 meters) in diameter and weighed 1,698 pounds (770 kilograms).

The X-3 had a maximum speed of 706 miles per hour (1,136 kilometers per hour) and a service ceiling of 38,000 feet (11,582 meters).

This view of the Douglas X-3 shows its very small wings and tail surfaces. (NASA)
This view of the Douglas X-3 shows its very small wings and tail surfaces. (NASA)

The X-3 was very underpowered with the J34 engines and could just reach Mach 1 in a shallow dive. Its highest speed, Mach 1.208, required a 30° dive. The research airplane was therefore never able to be used in flight testing in the supersonic speed range for which it was designed. Because of its design characteristics, though, it became useful in exploring stability and control problems encountered in the transonic range.

Two X-3 aircraft had been ordered from Douglas, but only one completed.

In addition to Bill Bridgeman, the Douglas X-3 was flown by Air Force test pilots Major Chuck Yeager and Lieutenant Colonel Frank Everest, and NACA High Speed Flight Station research pilot Joseph A. Walker.

NACA flight testing began in August 1954. On the tenth flight, 27 October, Joe Walker put the X-3 into abrupt left aileron rolls at 30,000 feet (9,144 meters), first at 0.92 Mach and then at Mach 1.05. Both times, the aircraft violently yawed to the right and then pitched down.

This was a new and little understood condition called inertial roll coupling. It was a result of the aircraft’s mass being concentrated within its fuselage, the torque reactions and gyroscopic effect of the turbojet engines and the inability of the wings and control surfaces to stabilize the airplane and overcome its rolling tendency. (Just two weeks earlier, North American Aviation’s Chief Test Pilot George S. Welch had been killed when the F-100A Super Sabre that he was testing also encountered inertial roll coupling and disintegrated.) A post-flight inspection found that the X-3 had reached its maximum design load. The X-3 was grounded for the next 11 months.

Joe Walker resumed flight testing the X-3 in 1955. It’s last flight was 23 May 1956. After the flight test program came to an end, the X-3 was turned over to the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio.

Douglas X-3 49-2892 at the National Museum of the United States Air Force. (NASM)

© 2016, Bryan R. Swopes

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