Tag Archives: George S. Welch

25 May 1953

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George S. Welch with North American YF-100A 52-5754. (North American Aviation, Inc.)

25 May 1953: North American Aviation Chief Test Pilot George S. Welch took the YF-100A Super Sabre, U.S. Air Force serial number 52-5754, for its first flight at Edwards Air Force Base. The airplane reached Mach 1.03.

Development of the Super Sabre began with an effort to increase the speed of the F-86D and F-86E Sabre fighters. The wings had more sweep and the airfoil sections were thinner. A much more powerful engine would be needed to achieve supersonic speed in level flight. As design work on the “Sabre 45” proceeded, the airplane evolved to a completely new design. Initially designated XF-100, continued refinements resulted in the first two aircraft being redesignated YF-100A.

North American Aviation Chief Test Pilot George S. Welch in the cockpit of the YF-100A, 52-5754, at Los Angeles International Airport. (North American Aviation, Inc.)
North American Aviation Chief Test Pilot George S. Welch in the cockpit of YF-100A 52-5754 at Los Angeles International Airport. (North American Aviation, Inc.)

The two YF-100As, 52-5754 and 52-5755, were 47 feet, 11¼ inches (14.611 meters) long with a wingspan of 36 feet, 7 inches (11.151 meters) and height of 16 feet, 3 inches (4.953 meters). The wings were swept to 45° at 25% chord, and had 0° angle of incidence and 0° dihedral. The ailerons were placed inboard on the wings to eliminate their twisting effects at high speed. The airplane had no flaps. The pre-production prototypes weighed 18,135 pounds (8,226 kilograms) empty, and had a gross weight of 24,789 pounds (11,244 kilograms).

The new air superiority fighter was powered by a Pratt & Whitney Turbo Wasp J57-P-7 engine. The J57 was a two-spool axial-flow turbojet which had a 16-stage compressor section (9 low- and 7 high-pressure stages) and a 3-stage turbine (2 high- and 1 low-pressure stages). The J57-P-7 had a Maximum Continuous Power rating of 8,000 pounds of thrust (35.586 kilonewtons) at 5,875 r.p.m., N1, and 9550 r.p.m., N2. The engine’s Military Power rating was 9,700 pounds thrust (43.148 kilonewtons) at 6,275 r.p.m./9,900 r.p.m., for 30 minutes; and 14,800 pounds thrust (65.834 kilonewtons) at 6,275 r.p.m./9,900 r.p.m. with afterburner, limited to five minutes. The engine was 20 feet, 9.7 inches (6.342 meters) long, 3 feet, 3.9 inches (1.014 meters) in diameter, and weighed 5,075 pounds (2,303 kilograms). Later production aircraft used a J57-P-39 engine, which had the same ratings.

Cutaway illustration ofa North American Aviation F-100A Super Sabre. (Boeing)
Cutaway illustration of a North American Aviation F-100A Super Sabre. (Boeing)
North American Aviation YF-100 Super Sabre 52-5754. (U.S. Air Force)
North American Aviation YF-100 Super Sabre 52-5754, 19 May 1953. (North American Aviation, Inc.)
The prototype North American Aviation YF-100A Super Sabre, 52-5754, with the North American F-100 team. Chief Test Pilot George S. Welch is in the center of the front row, seated. (North American Aviation, Inc.)

The YF-100A had a maximum speed of 660 miles per hour (1,062 kilometers per hour) at 43,350 feet (13,213 meters). The service ceiling was 52,600 feet (16,033 meters). Range with internal fuel was 422 miles (679 kilometers).

During testing, 52-5754 reached Mach 1.44 in a dive. On 29 October 1953, Colonel Frank K. Everest set a world speed record of 1,215.298 kilometers per hour (755.151 miles per hour) with 754.¹

In service with the United States Air Force, the Super Sabre’s mission changed from air superiority fighter to fighter bomber. It was used extensively during the Vietnam War. North American Aviation, Inc., built 2,294 single and tandem-seat Super Sabres between 1954 and 1959.

The F-100 pushed the State of the Art in the 1950s. There was a very steep learning curve back then. They remained in service with the USAF until 1979, and with the Republic of China Air Force until 1988. They also flew for France and Turkey.

In USAF service, 889 were destroyed in accidents, resulting in the death of 324 pilots. During the Vietnam War, the F-100s flew more combat sorties that all of the 15,000+ P-51 Mustangs during World War II. 186 Super Sabres were shot down by antiaircraft fire, but none were lost to enemy fighters.

North American Aviation YF-100A Super Sabre 52-5754. (U.S. Air Force)
North American Aviation YF-100A Super Sabre 52-5754 over Edwards Air Force Base, California, 25 May 1953. (North American Aviation, Inc.)
North American Aviation YF-100A Super Sabre 52-5754 lands on the dry lake at Edwards Air Force Base, California. (North American Aviation, Inc.)

George Welch was born George Lewis Schwartz, in Wilmington, Delaware, 10 May 1918. His parents changed his surname to Welch, his mother’s maiden name, so that he would not be effected by the anti-German prejudice that was widespread in America following World War I. He studied mechanical engineering at Purdue, and enlisted in the Army Air Corps in 1939.

North American Aviation YF-100A Super Sabre 52-5754 banks away from a chase plane during a flight test. (U.S. Air Force)

George S. Welch is best remembered as one of the heroes of Pearl Harbor. He was one of only two fighter pilots to get airborne during the Japanese surprise attack on Hawaii, 7 December 1941. Flying a Curtiss P-40B Warhawk, he shot down three Aichi D3A “Val” dive bombers and one Mitsubishi A6M2 Zero fighter. For this action, Lieutenant General H.H. “Hap” Arnold recommended the Medal of Honor, but because Lieutenant Welch had taken off without orders, an officer in his chain of command refused to endorse the nomination. He received the Distinguished Service Cross. During the War, Welch flew the Bell P-39 Airacobra and Lockheed P-38 Lightning on 348 combat missions. He had 16 confirmed aerial victories over Japanese airplanes and rose to the rank of Major.

Suffering from malaria, George Welch was out of combat, and when North American Aviation approached him to test the new P-51H Mustang, General Arnold authorized his resignation. Welch test flew the P-51, FJ-1 Fury, F-86 Sabre and F-100 Super Sabre. He was killed 12 October 1954 when his F-100A Super Sabre came apart in a 7 G pull up from a Mach 1.5 dive.

North American Aviation pre-production prototype YF-100A Super Sabre 52-5754 with drag chute deployed on landing at Edwards Air Force Base, California. (U.S. Air Force)
North American Aviation pre-production prototype YF-100A Super Sabre 52-5754 with drag chute deployed on landing at Edwards Air Force Base, California. The extended pitot boom is used to calibrate instruments early in the flight test program. (U.S. Air Force)
North American Aviation YF-100 Super Sabre 52-5754 with external fuel tanks, parked on the dry lake at Edwards Air Force Base, California. (U.S. Air Force)

¹ FAI Record File Number 8868

© 2018, Bryan R. Swopes

26 April 1948

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est Pilot George Welch flying the prototype North American Aviation XP-86 Sabre, 45-59597. (U.S. Air Force)
North American Aviation test pilot George S. Welch, flying the first of three XP-86 prototypes, serial number 45-59597. (North American Aviation, Inc.)

26 April 1948: At Muroc Field (now known as Edwards Air Force Base), in the high desert of southern California, North American Aviation test pilot George Welch put the prototype XP-86 Sabre, 45-59597, into a 40° dive and broke the Sound Barrier. It is only the second U.S. aircraft to fly supersonic. The first was the Bell X-1, piloted by Chuck Yeager, only a few months earlier.

Or, maybe not.

In his book, Aces Wild: The Race For Mach 1, fellow North American Aviation test pilot Albert W. Blackburn makes the case that George Welch had taken the prototype XP-86 Sabre supersonic on its first flight, 1 October 1947, and that he had done so three times before Chuck Yeager first broke the Sound Barrier with the Bell X-1 rocketplane, 14 October 1947. Blackburn described two runs through the NACA radar theodolite with speeds of Mach 1.02 and 1.04 on 13 November 1947.

Mr. Blackburn speculates—convincingly, in my opinion—that Secretary of the Air Force W. Stuart Symington, Jr., ordered that Welch’s excursions beyond Mach 1 were to remain secret. However, during a radio interview, British test pilot Wing Commander Roland Prosper (“Bee”) Beamont, C.B.E, D.S.O. and Bar, D.F.C. and Bar, stated that he had flown through the Sound Barrier in the number two XP-86 Sabre prototype (45-59598). Once that news became public, the U.S. Air Force released a statement that George Welch had flown beyond Mach 1 earlier, but gave the date as 26 April 1948.

Test pilot George S. Welch, wearing his distinctive orange helmet, in the cockpit of the prototype XP-86. This photograph was taken 14 October 1947. (U.S. Air Force)
Test pilot George S. Welch, wearing his distinctive orange helmet, in the cockpit of the prototype XP-86. This photograph was taken 14 October 1947. (U.S. Air Force)

It wasn’t long after the first flight of the XP-86 on October 1, 1947, that Welch dropped into Horkey’s [Edward J. Horkey, an aerodynamicist at North American Aviation] office at the Inglewood plant. He wanted to talk about his recent flight and some “funny” readings in the airspeed indicator. He had made a straight-out climb to more than 35,000 feet. Then, turning back toward Muroc Dry Lake, he began a full-power, fairly steep descent.

“I started at about 290 knots,” Welch was explaining to Horkey. “In no time I’m at 350. I’m still going down, and I’m still accelerating but the airspeed indicator seems stuck like there’s some kind of obstruction in the pitot tube. I push over a little steeper and by this time I’m through 30,000 feet. All of a sudden, the airspeed indicator flips to 410 knots. The aircraft feels fine, no funny noises, no vibration. Wanted to roll off to the left, but no big deal. Still, I leveled out at about 25,000 and came back on the power. The airspeed flicked back to 390. What do you think?”

“. . . You may be running into some Mach effects. . . .”

— Aces Wild: The Race For Mach 1, by Al Blackburn, Scholarly Resources Inc., Wilmington, Delaware, 1999, at Pages 147–148.

The “funny” reading of the airspeed indicator became known as the “Mach jump.” George Welch was the first to describe it.

The Sabre became a legendary jet fighter during the Korean War. 9,860 were built by North American, as well as by licensees in Canada, Australia and Japan.

George Welch had been recommended for the Medal of Honor for his actions as a P-40 Warhawk fighter pilot in Hawaii, December 7, 1941. He was killed while testing a North American Aviation F-100A Super Sabre, 12 October 1954.

Test pilot George S. Welch with a North American Aviation F-86 Sabre. (San Diego Air and Space Museum Archives)

© 2018, Bryan R. Swopes

22 December 1949

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North American Aviation YF-86D Sabre 50-577
North American Aviation YF-86D Sabre 50-577. (U.S. Air Force)

22 December 1949: North American Aviation, Inc., test pilot George S. Welch made the first flight of the YF-86D Sabre, 50-577 (c/n 164-1, at Edwards Air Force Base, in the high desert of southern California.

Based on the F-86A day fighter, the F-86D (originally designated YF-95) was a radar-equipped, rocket-armed, all-weather interceptor. Its first flight took place only nine years after the first flight of North American’s prototype NA-73X, which would become the famous P-51 Mustang fighter of World War II. This was an amazing jump in technology in just a few years.

The interceptor was intended to be an improved variant of the F-86A Sabre day fighter. During development, though, so many changes became necessary that the F-86D shared only about 25% of its parts of the F-86A. Essentially an new airplane, the Air Force assigned it the designation YF-95. It would revert to the F-86D designation before it actually flew.

North American Aviation YF-86D Sabre 50-577, the first of two service test aircraft, at the North American Aviation flight line, Los Angeles International Airport. (North American Aviation)
North American Aviation YF-86D Sabre 50-577, the first of two service test aircraft, at the North American Aviation flight line, Los Angeles International Airport. (North American Aviation, Inc.)

The first YF-86D (still identified as YF-95) was rolled out at North American’s Inglewood plant in September 1949. In late November it was partially disassembled to be transported by truck to Edwards Air Force Base, about 120 miles (193 kilometers) away. The airplane was then reassembled and ground tested to prepare it for flight.

North American Aviation, Inc., F-86D-1-NA Sabre 50-456, the second production aircraft. (Ray Wagner Collection, San Diego Air & Space Museum Archives)
North American Aviation, Inc., F-86D-1-NA Sabre 50-456, s/n 165-2, the second production aircraft (Ray Wagner Collection, San Diego Air & Space Museum Archives)
North American Aviation, Inc., F-86D-1-NA Sabre 50-458, s/n 165-4. (Ray Wagner Collection, San Diego Air & Space Museum Archives)

The first two test aircraft carried no armament or fire control/radar system and retained the sliding canopy of the F-86A. This would be replaced with a hinged “clamshell” canopy in production models. The airplane was 40 feet, 3.1 inches (12.271 meters) long with a wingspan of 37 feet, 1 inch (11.294 meters) and overall height of 15 feet, 0 inches (4.572 meters). Its empty weight was 12,470 pounds (5,656 kilograms) and maximum takeoff weight was 18,483 pounds (8,384 kilograms).

The service test aircraft and early production airplanes were powered by a General Electric J47-GE-17 single-shaft axial-flow turbojet engine, producing 5,425 pounds of thrust (24.132 kilonewtons) at 7,950 r.p.m., or 7,500 pounds (33.362 kilonewtons) with afterburner. This engine was equipped with an electronic fuel control system which substantially reduced the pilot’s workload. The engine had a 12-stage compressor, 8 combustion chambers, and single-stage turbine. It was 226.0 inches (5.740 meters) long, 39.75 inches (1.010 meters) in diameters, and weighed 3,000 pounds (1,361 kilograms).

The first production aircraft, F-86D-1-NA Sabre, had a maximum speed of 614 knots (707 miles per hour/1,137 kilometers per hour) at Sea Level, and 539 knots (620 miles per hour/998 kilometers per hour)at 40,000 feet (12,192 meters). From a standing start, the interceptor could climb to 40,000 feet in 5 minutes, 54 seconds with a full combat load. The service ceiling was 54,000 feet (16,460 meters).

North American Aviation, Inc., F-86D-15-NA Sabre 50-574 (c/n 165-120), firing 2.75-inch FFAR rockets, circa 1950. (NASM)
A production North American Aviation F-86D-60-NA Sabre, 53-4061, firing a salvo of 2.75-inch FFAR rockets. (U.S. Air Force)

The F-86D Sabre carried no guns. Instead, its armament consisted of twenty-four 2.75-inch (70 millimeter) Mk 4 Folding Fin Aerial Rockets (FFAR) with explosive warheads, carried in a retractable tray in the airplane’s belly. A Hughes electronic fire control computer was used to calculate an interception path and determine the firing point for the unguided rockets.

The aircraft was so complex that the pilot training course was the longest of any aircraft in the U.S. Air Force inventory, including the Boeing B-47 Stratojet.

The single-seat F-86D Sabre was nearly 50 knots faster than the contemporary twin-engine Northrop F-89 Scorpion and Lockheed F-94 Starfire, both of which carried a two-man crew. North American Aviation built 2,504 F-86D Sabres, and these equipped nearly two-thirds of the Air Defense Command interceptor squadrons.

North American Aviation YF-86 Sabre 50-577, NACA 149. (NASA)
North American Aviation YF-86D Sabre 50-577, NACA 149, at the NACA Ames Research Center, Moffett Field, California. (NASA)

After the Air Force service test program was completed, 50-577 was transferred to the National Advisory Committee on Aeronautics (NACA) Ames Aeronautical Laboratory at Moffett Field, California, and designated NACA 149. It was used as a variable stability aircraft for flight testing various control configurations for feel, sensitivity and response.

NACA 149 remained at Ames from 26 June 1952 to 15 February 1960.

© 2018, Bryan R. Swopes

14 October 1947

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Test pilot George S. Welch, wearing his distinctive orange helmet, in the cockpit of the prototype North American Aviation XP-86. (U.S. Air Force)

14 October 1947: Twenty minutes before Captain Charles E. (“Chuck”) Yeager broke the sound barrier with a Bell X-1 rocketplane, North American Aviation Chief Test Pilot George S. Welch put the swept-wing XP-86 prototype, serial number 45-59597, into a shallow dive from 37,000 feet (11,278 meters) and accelerated. In direct violation of orders from the Secretary of the Air Force to not do so, Welch broke the “sound barrier.”

Witnesses on the ground heard the distinctive “B-BOOM” double-shock as the aircraft exceeded the speed of sound. Welch was the first to observe “Mach jump” as the airspeed indicator momentarily indicated higher due to the compression of air in front of the aircraft.

Estimates are that the XP-86 reached Mach 1.02–1.04 on this flight.

George S. Welch with his MG sports car and the North American XP-86. (Unattributed)
George S. Welch with his MG T-series sports car and North American Aviation  XP-86 45-59597. (Unattributed)

© 2015, Bryan R. Swopes