Monthly Archives: March 2025

25 March 1956

Aviation, , , , , , , , , , , , , ,
Martin XB-51 46-685, the number one prototype, on takeoff. (U.S. Air Force)
Martin XB-51 46-685, the number one prototype, on takeoff. (Lockheed Martin)

25 March 1956: At approximately 10:50 a.m., the first of two prototype Martin XB-51 three-engine attack bombers, serial number 46-685, crashed on takeoff from Runway 22 at El Paso International Airport (ELP). The pilot, Major James Otto Rudolph, United States Air Force, survived the crash although he was  seriously burned. Staff Sergeant Wilbur Robert Savage, 28, engineer, was killed. Major Rudolph died of injuries 16 April 1956.

Pieces of wreckage were marked “Gilbert XF-120” which had been painted on the airplane for the filming of the William Holden, Lloyd Nolan movie, “Toward The Unknown.” (Toluca Productions, 1956). The second prototype, 46-686, had previously crashed at Edwards AFB.

A newspaper article from the El Paso Times is quoted below [I have corrected some typographical errors]:

03/26/1956

Bill Feather
El Paso Times

A sleek jet bomber, carrying a full load of fuel, crashed while attempting a take-off at International Airport Sunday morning, killing the flight engineer and seriously injuring the pilot.

The XB-51, the only one of its type in existence, smashed through the fence at the end of the southwest runway and then began to disintegrate, spreading wreckage along a 250-yard trail.

Only the tail section of the three-engine bomber was left intact.

Name of the dead man, a 28-year-old staff sergeant was withheld pending notification of next of kin.

Flying the aircraft was Maj. James O. Rudolph, 36, one of the top test pilots in the Air Force.

He suffered severe burns and was taken Sunday afternoon in an emergency flight to Brooke Army Hospital in San Antonio.

The XB-51, based at Edwards Air Force Base in Muroc, Calif., was being flown to Eglin Air Force Base, Florida, where it was to be used in the filming of a Warner Brothers movie, “Toward the Unknown.”

Identification of the aircraft was confused for a short time after the crash.

A piece of wreckage with the notation “Gilbert XF-120” was found nearby.

HAD REFUELED

Air Force spokesmen explained that the XF designation had been painted on the plane for use in the movie.

The airplane had been refueled at International Airport and started its takeoff at 10:30 a.m.

Witnesses said the plane got about three feet above the ground and suddenly settled. The tail dragged first and then the rest of the airplane settled, running at high speed.

It ripped through a barbed wire fence at the end of the runway, raced across Airport Road and then began to go to pieces.

After crashing, it burned and several explosions threatened firemen, rescuers and spectators who crowded around the flaming aircraft.

First person to the scene of the crash was Eddie C. Wilkerson, 1106 Del Monte Drive, tennis coach at Austin High School.

“I was just turning into the road to the airport when the plane was taking off. I don’t believe it ever got airborne.

“I looked back and saw a big ball of smoke, so I just wheeled my car around.”

Wilkerson said that when he arrived, the major was lying on the ground about 15 feet from the burning wreckage.

“His clothes were burning so I started tearing them off.”

Other witnesses to the crash arrived and helped Wilkerson move the major to a safer place, away from the intense heat of the flaming aircraft.

Capt. John D. Chandler, a doctor at the Biggs Hospital, was at the airport when the crash occurred and he was one of the first persons at the scene. He administered aid to the injured man until an ambulance arrived. Later Capt. Chandler flew to San Antonio with Maj. Rudolph.

A fire truck from International Airport was rushed to the scene almost as soon as the plane stopped its forward motion.

Sunday drivers were attracted to the scene by the tower of smoke and the heavy traffic delayed the arrival of fire trucks from Biggs Air Force Base.

The plane was one of two XB-51s built by Martin Aircraft Co. and was completed in 1953.

The first one crashed at Muroc, Calif., in 1952.

Air Force spokesmen said the aircraft was comparable to the B-47, which was accepted instead of the XB-51 for use in the Air Force.

Its three jet engines one in each wing and on in the fuselage, were capable of driving the craft at tremendous speeds. The aircraft had broken the sound barrier, spokesmen said.

Its sleek lines gave it the appearance of a fighter rather than a medium bomber.

Normally, the airplane carried a crew of three.

Recently it had been used in assisting the Army in missile and anti-aircraft development at Aberdeen Proving Ground, Md.

A board of officers was investigation the crash and two Air Force colonels arrived at Biggs Air Force Base from Muroc Sunday afternoon.

Military police from Ft. Bliss and Air Police patrolled the area about the crash Sunday afternoon, keeping away the curious.

— http://elpasotimes.typepad.com/morgue/2011/03/today-in-1956-plane-crash-kills-engineer-pilot-injured-as-bomber-falls-.html

James Otto Rudolph was born at Marion, Ohio, 8 February 1920, the first of two children of of Frank Otto Rudolph, a German immigrant who was employed as a secretary for the YMCA, and Helen Claire Shafer Rudolph.

Following two years of college, Rudolph enlisted as an Aviation Cadet, U.S. Army Air Corps, at Detroit, Michigan, 17 March 1941. He was 6 feet, 1inch (1.854 meters) tall and weighed 175 pounds (79.4 kilograms). He was commissioned as a Second Lieutenant, Air Reserve, 31 October 1941,and was promoted to First Lieutenant, Army of the United States (Air Corps), 5 August 1942. He was again promoted, to Captain, 15 June 1943. Following the end of World War II, Rudolph was promoted to the rank of Major, 19 September 1946. He remained in the Air Force, but with military needs shrinking, he reverted to the rank of First Lieutenant, with date of rank, 7 December 1944.

James Rudolph married Clara D.    in 194–

Major Rudolph graduated from the U.S. Air Force Experimental Flight Test Pilot School, Class 54-A, 2 July 1954. As a test pilot at Edwards Air Force Base, Rudolph was a project pilot in the FICON program in which Republic RF-84K Thunderflash reconnaissance planes were carried by modified Convair RB-36D bombers.

During his military career, Major Rudolph had been awarded the Air Medal with three oak leaf clusters (four awards).

After the crash on 25 March 1956, Major Rudolph was taken to Brooke Army Hospital, Fort Sam Houston, Texas, suffering from 2nd and 3rd degree burns over 38% of his body. He contracted septicemia and died there, 16 April 1956. He is buried at Arlington National Cemetery.

Wilbur Robert Savage was born 19 July 1927 at Dawsonville, Georgia. He was the son of Newton McKinley Savage and May Belle Carney Savage. He married to Ida Pedroza Aceves in 1948. They would have three children.

Staff Sergeant Savage’s remains were interred at Mountain View Cemetery, San Bernardino, California.

The first Martin XB-51, 46-585, in flight. (U.S. Air Force)

The Glenn L. Martin Co. XB-51 was a prototype jet-powered ground attack bomber. It was an unusual design for its time. The airplane had mid-mounted, variable-incidence swept wing, a T-tail and tandem landing gear with a configuration similar to that used on the Boeing B-47 Stratojet (and which had been tested using a Martin B-26 Marauder medium bomber.)

The XB-51 was operated by a pilot in a single-place cockpit with a bubble canopy, and a navigator station inside the fuselage, below and behind the pilot. The prototype was 85 feet, 1 inch (25.933 meters) long with a wingspan of 53 feet, 1 inch (16.180 meters) and overall height of 17 feet, 4 inches (5.283 meters). The total wing area was 548.0 square feet (50.9 square meters). The airplane had an empty weight of 30,906 pounds (14,019 kilograms) and a maximum overload takeoff weight of 62,452 pounds (28,328 kilograms).

Martin XB-51. (Glenn L. Martin Company)

The wings of the XB-51 were swept aft to 35° and had 6° anhedral. The wings’ angle of incidence (the relation of the chord to the fuselage longitudinal axis) could be adjusted to increase lift for takeoff and landing. They had 2° negative twist and were equipped with leading edge slats for improved low speed performance. Instead of ailerons, the XB-51 used spoilers.

Lloyd Nolan (“General Bill Banner”) and William Holden (“Major Lincoln Bond”) with the “Gilbert XF-120” in the 1956 Hollywood movie, “Toward the Unknown.” (Toluca Productions via Turner Classic Movies)

Power was supplied by three General Electric J47-GE-13 turbojet engines, with two located in nacelles outboard of the forward fuselage on 45° pylons, and a third installed in the tail with its intake on top of the fuselage. The J47-GE-13 was an axial-flow turbojet with a 12-stage compressor and single stage turbine. It had a normal power rating of 4,320 pounds of thrust (19.216 kilonewtons) at 7,370 r.p.m.; military power, 5,200 pounds (23.131 kilonewtons) at 7,950 r.p.m. (30-minute limit); and maximum power rating of 6,000 pounds(26.689 kilonewtons) at 7,950 r.p.m., with water/alcohol injection (5-minute limit). The engine was 12 feet, 0.0 inches (3.658 meters) long, 3 feet, 3.0 inches (0.991 meters) in diameter and weighed 2,525 pounds (1,145 kilograms). A Rocket Assisted Takeoff (RATO) system was also installed.

The XB-51 had a maximum speed of 560 knots (644 miles per hour/1,037 kilometers per hour) at Sea Level—0.85 Mach. The service ceiling was 39,400 feet (12,009 meters) and the maximum ferry range was 1,255 nautical miles (1,444 statute miles/2,324  kilometers).

Armament was planned for a maximum bomb load of 10,400 pounds (4,717 kilograms) carried internally in a rotary bomb bay, and eight M39 20 mm revolving autocannon mounted in the nose with 160 rounds of ammunition per gun. 5-inch High Velocity Aerial Rockets (HVAR) could be carried under the wings or in the bomb bay.

Martin XB-51 46-685 during engine start and ground run-up. (U.S. Air Force)

© 2019 Bryan R. Swopes

25 March 1955

Aviation, , , , , , , , , , ,
John W. Konrad in the cockpit of the prototype Vought XF8U-1 Crusader, Bu. No. 138899. (Vought Heritage)
John W. Konrad in the cockpit of the prototype Vought XF8U-1 Crusader, Bu. No. 138899. (Vought Heritage)

25 March 1955: Chance Vought Aircraft Corporation experimental test pilot John William Konrad took the first prototype XF8U-1 Crusader, Bu. No. 138899, for its first flight at Edwards Air Force Base in the high desert of Southern California.

The new fighter had been transported from the factory at Dallas, Texas, aboard a Douglas C-124C Globemaster II, on 3 March 1955. It was reassembled and all systems were checked. Taxi tests began on 14 March.

During the first flight on 25 March, the Crusader went supersonic in level flight. It was able to maintain supersonic speeds (not only for short periods in a dive) and was the first fighter aircraft to exceed 1,000 miles per hour in level flight (1,609 kilometers per hour).

Chance Vought test pilot John W. Konrad talks with engineers following the first test flight. (Chance Vought Aircraft Corporation photograph via Bill Spidle’s “Voughtworks” http://voughtworks.blogspot.com)

The F8U Crusader has a unique variable-incidence wing which can be raised to increase the angle of attack. This created more lift at low speeds for takeoff and landing aboard aircraft carriers, but allows the fuselage to remain fairly level for better forward visibility.

The test program went so well that the first production airplane, F8U-1 Crusader Bu. No. 140444, made its first flight just over six months after the prototype’s.

Prototype Vought XF8U-1 Crusader during a test flight, 25 March 1955. (Vought)
Prototype Vought XF8U-1 Crusader Bu. No. 138899 during a test flight, 25 March 1955. (Vought Heritage)

The Chance Vought F8U-1 was nearly identical to the prototype XF8U-1. It was a single-place, single-engine swept-wing fighter designed to operate from the United States Navy’s aircraft carriers. The F8U-1 was 54 feet, 2.75 inches (16.529 meters) long with a wingspan of 35 feet, 8 inches (10.871 meters) and height of 15 feet, 9.1 inches (4.803 meters). With wings folded, the airplane’s width was reduced to 22 feet, 6 inches (6.858 meters).

The Crusader’s wing angle of incidence was adjustable in flight. It had a total area of 375 square feet (34.8 square meters). The leading edges were swept aft to 47°, and the outer panels had a 1 foot, 0.7 inch “dog tooth.” The wings had 5° anhedral, while the horizontal stabilator had 5° 25′ dihedral. The stabilator’s leading edges were swept 50°.

Its empty weight was 15,513 pounds (7,037 kilograms) and maximum takeoff weight was 27,500 pounds (12,474 kilograms).

Prototype Chance Vought XF8U-1 Crusader in landing configuration. (Vought Heritage)

Early production aircraft were powered by a Pratt & Whitney J57-P-4 engine. This was a two-spool, axial-flow turbojet engine with a 16-stage compressor and 3-stage turbine. The J57-P-4 had a normal power rating of 8,700 pounds of thrust (38.70 kilonewtons); military power, 10,200 pounds (45.37 kilonewtons), and a maximum rating of 16,000 pounds (71.17 kilonewtons) with afterburner. The engine was 20 feet, 10 inches (6.350 meters) long and 3 feet, 5 inches (1.041 meters) in diameter.

The F8U-1 had a cruising speed of 494 knots (569 miles per hour/915 kilometers per hour). Its maximum speed was 637 knots (733 miles per hour/1,180 kilometers per hour) at Sea Level—0.95 Mach—and 860 knots (990 miles per hour/1,180 kilometers per hour) at 35,000 feet (10,668 meters)—Mach 1.50.  It had a service ceiling of 42,300 feet (12,893 meters) and combat range of 1,280 nautical miles miles (1,473 statute miles/2,371 kilometers).

The F8U Crusader was known as “The Last of the Gunfighters” because it was the last American fighter aircraft to be designed with guns as the primary armament. It carried four Colt Mark 12 20-mm autocannon with 500 rounds of ammunition. It could also carry two AIM-9 Sidewinder infrared-homing air-to-air missiles.

Because of a high accident rate, the Crusader has also been called “The Ensign Killer.”

Vought XF8U-1 Crusader parked on Rogers Dry Lake, Edwards Air Force Base. (Vought)
Vought XF8U-1 Crusader Bu. No. 138899 parked on Rogers Dry Lake, Edwards Air Force Base. (Vought Heritage)

The Vought F8U Crusader was in production from 1955 through 1964 with a total of 1,261 built in both fighter and photo reconnaissance versions.

Vought XF8U-1 Crusader Bu. No. 138899 parked on Rogers Dry Lake, Edwards Air Force Base. (Vought Heritage)

During five years of testing, Bu. No. 138899 made 508 flights. It was donated to the Smithsonian Institution in 1960. The restored prototype is now at The Museum of Flight, Seattle, Washington.

According to information recently discovered by The Museum of Flight, fighter pilot, test pilot and future astronaut John Herschel Glenn, Jr., made his first flight in a Crusader when he flew Bu. No. 138899 on 4 May 1956. According to Glenn’s logbook, he made two flights in the prototype on that date, totaling 2 hours of flight time. Many thanks to Mike Martinez, a docent for the museum for providing this information.

The Vought XF8U-1 has been restored by The Museum of Flight at Paine Field, Stattle, Washington. (The Museum of Flight)
The first of two prototypes, Chance Vought XF8U-1 Crusader, Bu. No. 138899, has been restored by The Museum of Flight at Paine Field, Seattle, Washington. The Crusader’s variable incidence wing is in the raised take-off/landing position. (The Museum of Flight)

John William Konrad was born 25 November 1923 at San Diego, California. He was the second of three children of  William Konrad, a salesman, and Emma Louise Stensrud Konrad.

Konrad became interested in aviation at an early age, learning to fly in a Piper Cub at the age of 15. After graduating from high school, he enlisted as a private in the U.S. Army Air Corps at San Diego, 26 February 1943. Konrad was 5 feet, 3 inches (1.60 meters) tall and weighed 118 pounds (53.5 kilograms). He trained as a pilot and flew Boeing B-17 Flying Fortress heavy bombers with the 305th Bombardment Group (Heavy), stationed at RAF Chelveston, during World War II. He later flew Douglas C-47 Skytrains during the Berlin Airlift.

Konrad married Miss Harriet Marilyn Hastings at Clearwater, Florida, 11 February 1945. They would have two children.

Following the War, Konrad was selected for the first test pilot training class at Wright Field, then was assigned to Muroc Army Airfield (Edwards Air Force Base) in California, where he graduated from the Air Force Experimental Flight Test Pilot School, Class 51-C, 19 May 1952.

Konrad resigned from the Air Force in 1953 and joined the Chance Vought Aircraft Corporation in Dallas, Texas, as a test pilot. In addition the the XF8U-1 Crusader, he also made the first flight of the Ling-Temco-Vought A-7 Corsair II, and the experimental LTV XC-142 tiltwing V/STOL transport in 1964. He was appointed Director Test Operations in 1965. Konrad retired from Vought in 1988 after 25 years with the company.

After retiring, John Konrad continued to fly a Goodyear FG-1D Corsair with Commemorative Air Force.

John William Konrad, Sr., Captain, United States Air Force, died 20 September 2006 at Dallas, Texas. He is buried at the Dallas–Fort Worth National Cemetery.

John William Konrad. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

© 2019, Bryan R. Swopes

24 March 2000

Aviation, , , , , , , , ,
The first super Jolly Green Giant, 66-14428, now upgraded to an MH-53J Pave Low IIIE, assigned to the 551st Special operations Squadron, 58th Special operations Wing, in flight near Kirtland Air Force Base, New Mexico, 24 March 2000. (U.S. Air Force)
The first Super Jolly Green Giant, Sikorsky HH-53B 66-14428, now upgraded to an MH-53J Pave Low IIIE Enhanced, assigned to the 551st Special Operations Squadron, 58th Special Operations Wing, in flight near Kirtland Air Force Base, New Mexico, 24 March 2000. (Master Sergeant Dave Dolan, U.S. Air Force)

24 March 2000: In flight near Kirtland AFB, New Mexico, is this Sikorsky MH-53J Pave Low IIIE, a “Super Jolly Green Giant” special operations helicopter assigned to the 551st Special Operations Squadron. This helicopter, serial number 66-14428, was the very first HH-53B built. [A photograph of its first flight is posted on TDiA at “15 March 1967” https://www.thisdayinaviation.com/15-march-1967/ ]

66-14428 was sent to The Boneyard at Davis-Monthan AFB, 7 January 2007, after 40 years of service.
© 2019, Bryan R. Swopes

24 March 1960

Aviation, , , , , , , , , , , , ,
Tupolev Tu-114 CCCP-76459, holder of nineteen FAI World Records for Speed. (Уголок неба)

24 March 1960: Over a 1,000-kilometer course at Sternberg Point Observatory,¹ a Tupolev Tu-114 Rossiya four-engine turboprop airliner, serial number 88402, registered CCCP-76459, set eight Fédération Aéronautique Internationale flight records, including a world speed record of 871.38 kilometers per hour (541.45 miles per hour), while carrying a load of 25,000 kilograms (55,115.6 pounds).²

Colonel Ivan Moiseevich Sukhomlin.

The flight crew for these records were Tupolev Design Bureau senior test pilot Colonel Ivan Moiseevich Sukhomlin, Pilot, and Colonel Boris Mikhailovich Timoshok, Co-Pilot, and four others.

On 1 April 1960, Colonel Sukhomline flew the Tu-114 to set another seven speed records over a 2,000 kilometers course, at 857.277 kilometers per hour (532.687 miles per hour), while carrying a 20,000 kilogram payload (44,092 pounds).³

On 9 April, Colonel Sukhomlin and co-pilot Konstantine Sapielkine flew the Tu-114 over a 5,000 kilometer closed circuit, again with a 25,000 kilogram payload, at an average speed of 877.21 kilometers per hour (545.07 miles per hour). Four more FAI records were set.⁴

These are the fastest speed records ever established for any propeller-driven airplane. The records were retired by the FAI due to changes in rules.

Tupolev Tu-114 three-view illustration. (Уголок неба)

The record-setting Tu-114 was the second production airliner.

The Tupolev Tu-114 Rossiya was a four-engine, turboprop-powered airliner developed from the Tu-95 Bear nuclear-capable long-range heavy bomber. It had a flight crew of five, two pilots, a navigator and two flight engineers, and could be configured to carry from 120 to 220 passengers, or 30,000 kilograms of cargo.

Colonel Alexei Petrovich Yakimov.

The Tu-114 made its first flight 15 November 1957 under the command of Colonel Alexei Petrovich Yakimov,  and began regular service with Aeroflot 24 April 1961.

The Tu-114 is 54.10 meters (177 feet, 6 inches) long, with a wingspan of 51.10 meters (167 feet, 8 inches) and overall height of 15.50 meters (50 feet, 10 inches). The wings are swept aft to 35° at ¼-chord, and they have significant anhedral. Total wing area is 311.1 square meters (3,348.7 square feet).

The airliner’s empty weight is 93,500 kilograms (206,132 pounds) and maximum takeoff weight is 179,000 kilograms (394,628 pounds).

Tupolev Tu-114 CCCP-76459, World Record holder. (Уголок неба)

The Tu-114 was powered by four Kuznetsov NK-12MV turboprop engines, each driving two contra-rotating four-bladed propellers. The NK-12 was rated at 14,795 shaft horsepower (10.89 megawatts). The NK-12 is a single-shaft axial-flow turboprop engine with a 14-stage compressor section and 5-stage turbine. The engine is 19 feet, 8.2 inches (6.000 meters) long, 3 feet, 11.3 inches (1.151 meters) in diameter, and weighs 5,181 pounds (2,350 kilograms).

The Tu-114 had a cruise speed of 770 kilometers per hour (478 miles per hour) at 9,000 meters (29,528 feet) (0.70 Mach), and a maximum speed of 894 kilometers per hour (556 miles per hour) at 8,000 meters (26,247 feet) (0.80 Mach). The airliner has a practical range of 7,000 kilometers (4,350 miles) and maximum ferry range of 8,800 kilometers (5,468 miles). The service ceiling as 12,000 meters (39,370 feet).

A Tupolev Tu-114 at Paris-Le Bourget after a flight from Budapest, Hungary, 5 June 1959. (Magyar Hírek Folyóirat/Wikipedia)

The Tupolev Tu-114 was produced from 1958 to 1963, with 32 built. They were in service until 1976.

CCCP-76459, the world-record-setting airliner, was displayed at Novogorod Airport, Veliky Novogorod, Russia, in 1977. It was destroyed by fire in 1990.

The world-record-setting Tupolev Tu-114, CCCP-76459 (s/n 88401), was destroyed by fire at Novogorod in 1990. (Detlev Grass via Авиация, понятная всем )

An interesting 10-minute 1959 color film about the prototype Tu-114 Rossiya can be viewed on YouTube:

¹ The Sternberg Point Observatory, also known as the Sternberg Astronomical Institute (Государственный астрономический институт имени Штернберга), is located in Moscow, Russia.

Sternberg Astronomical Institute

² FAI Record File Numbers 8125, 8126, 8127, 8128, 8129, 8130, 8131 and 8880: 871.38 kilometers per hour (541.45 miles per hour)

³ FAI Record File Numbers 8133, 8134, 8135, 8136, 8137, 8138 and 8139: 857.277 kilometers per hour (532.687 miles per hour)

⁴ FAI Record File Numbers 3663, 3664, 3665 and 3666: 877.21 kilometers per hour (545.07 miles per hour)

© 2019, Bryan R. Swopes

24 March 1960

Aviation, Space Flight, , , , , , , , , , , , ,
Joseph Albert Walker in the cockpit of North American Aviation X-15A 56-6670, after a flight, 1960. (NASA)
Joseph Albert Walker in the cockpit of North American Aviation X-15A 56-6670, after a flight, 1960. (NASA)

24 March 1960: After North American Aviation’s Chief Engineering Test Pilot, Albert Scott Crossfield, had made the first flights in the new X-15 hypersonic research rocketplane (one gliding, eight powered), NASA Chief Research Test Pilot Joseph Albert Walker made his first familiarization flight.

The X-15, 56-6670, the first of three built by North American Aviation, Inc., was carried aloft under the right wing of a Boeing NB-52A Stratofortress, 52-003, flown by John E. Allavie and Fitzhugh L. Fulton.

Fitz Fulton and and Jack Allavie with a Boeing NB-52 drop ship. (Jet Pilot Overseas)

The rocketplane was dropped from the mothership over Rosamond Dry Lake at 15:43:23.0 local time, and Joe Walker ignited the Reaction Motors XLR-11 rocket engine. The engine burned for 272.0 seconds, accelerating Walker and the X-15 to Mach 2.0 (1,320 miles per hour/2,124.3 kilometers per hour) and a peak altitude of 48,630 feet (14,822.4 meters). Walker landed on Rogers Dry Lake at Edwards Air Force Base after a flight of 9 minutes, 8.0 seconds.

Joe Walker made 25 flights in the three X-15 rocket planes from 24 March 1960 to 22 August 1963. He achieved a maximum Mach number of 5.92, maximum speed of 4,104 miles per hour (6,605 kilometers per hour) and maximum altitude of 354,200 feet (107,960 meters).

Joe Walker with the Number 2 North American Aviation X-15, 56-6671, on Rogers Dry Lake. (NASA)

Joe Walker was killed in a mid-air collision between his Lockheed F-104N Starfighter and a North American Aviation XB-70A Valkyrie near Barstow, California, 1 June 1966.

The number one ship, 56-6670, made 81 of the 199 flights of the X-15 Program. It was the first to fly, and also the last, 24 October 1968. Today, it is in the collection of the Smithsonian Institution National Air and Space Museum.

North American Aviation, Inc. X-15A 56-6670 on Rogers Dry Lake, Edwards Air Force Base, California. (NASA)
North American Aviation, Inc. X-15A 56-6670 on Rogers Dry Lake, Edwards Air Force Base, California. (NASA)

© 2019, Bryan R. Swopes