26 December 1948: Test pilot Ivan Yevgrafovich Federov (also reported as Ivan E. Fyodorov) became the first pilot in the Soviet Union to exceed Mach 1 when he flew the Lavochkin La-176 in a dive from 9,050 meters (29,692 feet) to 6,000 meters (19,685 feet).
It was first thought that the La-176’s airspeed indicator had malfunctioned, but during subsequent testing conducted the first week of January 1949, Federov repeated the dive and six times reached Mach 1.02.
The La-176 was destroyed when its canopy failed during supersonic flight. Test pilot I.V. Sokolovsky was killed.
The La-176 was a single-seat, single-engine fighter, derived from the earlier La-168. The leading edge of its wings and tail surfaces were swept at 45°. The fighter was 36 feet (10.973 meters) long with a wingspan of 28 feet, 2 inches (8.585 meters). It had an empty weight of 3,111 kilograms (6,858.6 pounds) and loaded weight of 4,631 kilograms (10,210 pounds).
The La-176 was powered by a Klimov VK-1 centrifugal-flow turbojet, developed from the Rolls-Royce Nene. The British engines were reverse-engineered by Vladimir Yakovlevich Klimov and manufactured at Factory No. 45 in Moscow as the Klimov VK-1. The VK-1 used a single-stage centrifugal-flow compressor, 9 combustion chambers and a single-stage axial-flow turbine. It produced a maximum 26.5 kilonewtons of thrust (5,957 pounds of thrust). The VK-1 was 2.600 meters (8 feet, 6.4 inches) long, 1.300 meters (4 feet, 3.2 inches) in diameter, and weighed 872 kilograms (1,922 pounds).
The swept-wing jet had a maximum speed of 648 miles per hour (1,042.85 kilometers per hour) and a range of 621 miles (999.4 kilometers).
Armament consisted of one Nudelman N-37 30 mm cannon and two Nudelman-Suranov NS-23 23 mm cannon.
Colonel Ivan Yevgrafovich Federov (b. 23 February 1914) was a Soviet Air Force fighter pilot who fought in the Spanish civil war (where he was known as Diablo Rojo, the Red Devil), the Russo-Finish War, World War II, China and Korea. He may have shot down as many as 135 enemy airplanes. He was personally awarded the Iron Cross by Adolf Hitler, Chancellor of Germany, in 1941. His Soviet Awards include Hero of the Soviet Union, the Order of Lenin, Order of Alexander Nevsky, Order of the Red Banner, Order of the Patriotic War 1st Degree, Order of the Patriotic War 2nd Degree, and Order of the Red Star.
12 December 1953: On its tenth flight, U.S. Air Force test pilot Major Chuck Yeager flew the Bell X-1A rocket plane to Mach 2.44 (1,621 miles per hour/2,609 kilometers per hour) at 74,700 feet (22,769 meters), faster than anyone had flown before.
After the rocket engine was shut down, the X-1A tumbled out of control—”divergent in three axes” in test pilot speak—and fell out of the sky. It dropped nearly 50,000 feet (15,240 meters) in 70 seconds. Yeager was exposed to accelerations of +8 to -1.5 g’s. The motion was so violent that Yeager cracked the rocketplane’s canopy with his flight helmet.
Yeager was finally able to recover by 30,000 feet (9,144 meters) and landed safely at Edwards Air Force Base.
Yeager later remarked that if the X-1A had an ejection seat he would have used it.
Bell Aircraft Corporation engineers had warned Yeager not to exceed Mach 2.3.
The following is from Major Charles E. Yeager’s official post-flight report:
“After a normal drop at 31,000 feet, chambers #4, #2, and #1 were ignited and [the] airplane was accelerated up to .8 Mach number. A flight path was formed holding .8 Mach number up to 43,000 feet where chamber #3 was ignited and the airplane accelerated in level flight to 1.1 Mach number. A climb was again started passing through 50,000 feet at 1.1 Mach number, 60,000 feet at 1.2 Mach number and a push-over was started at 62,000 feet. The top of the round-out occurred at 76,000 feet and 1.9 Mach number. The airplane was accelerated in level flight up to 2.4 [2.535 indicated] Mach number where all of the rocket chambers were cut. The flight path was very normal and nothing uneventful [sic] happened up to this point. After the engine was cut, the airplane went into a Dutch roll for approximately 2 oscillations and then started rolling to the right at a very rapid rate of roll. Full aileron and opposite rudder were applied with no effect on the rate of roll of the airplane. After approximately 8 to 10 complete rolls, the airplane stopped rolling in the inverted position and after approximately one-half of one second started rolling to the left at a rate in excess of 360 degrees per second, estimated by the pilot. At this point the pilot was completely disoriented and was not sure what maneuvers the airplane went through following the high rates of roll. Several very high ‘g’ loads both positive and negative and side loads were felt by the pilot. At one point during a negative ‘g’ load, the pilot felt the inner liner of the canopy break as the top of his pressure suit helmet came in contact with it. The first maneuver recognized by the pilot was an inverted spin at approximately 33,000 feet. The airplane then fell off into the normal spin from which the pilot recovered at 25,000 feet.”
The following is a transcript of radio transmissions during the flight:
Yeager: Illegible [inaudible]—gasping—I’m down to 25,000 over Tehachapi. Don’t know whether I can get back to the base or not. Chase (Ridley): At 25,000 feet, Chuck? Yeager: Can’t say much more, I got to (blurry—save myself). Yeager: I’m—(illegible)—(Christ!) Chase (Ridley): What say, Chuck? Yeager: I say I don’t know if I tore anything up or not but Christ! Chase (Murray): Tell us where you are if you can. Yeager: I think I can get back to the base okay, Jack. Boy, I’m not going to do that any more. Chase (Murray): Try to tell us where you are, Chuck. Yeager: I’m (gasping)…I’ll tell you in a minute. I got 1800 lbs [nitrogen] source pressure. Yeager: I don’t think you’ll have to run a structure demonstration on this damned thing! Chase (Murray): Chuck from Murray, if you can give me altitude and heading, I’ll try to check you from outside. Yeager: Be down at 18,000 feet. I’m about—I’ll be over the base at about 15,000 feet in a minute. Chase (Murray): Yes, sir. Yeager: Those guys were so right! Yeager: Source pressure is still 15 seconds, I’m getting OK now. Yeager: I got all the oscillograph data switches off. 4 fps camera off, it’s okay. Bell Truck: Jettison and vent your tanks. Yeager: I have already jettisoned. Now I’m venting both lox and fuel. Leaving hydrogen peroxide alone. Bell Truck: Roger. Yeager: I cut it, I got—in real bad trouble up there. Yeager: Over the base right now, Kit, at 14,500 feet. Chase (Murray): I have you.
In his autobiography, Always Another Dawn, NACA test pilot Albert Scott Crossfield wrote:
Probably no other pilot could have come through that experience alive. Much later I asked Yeager, as a matter of professional interest, exactly how he regained control of the ship. He was vague in his reply, but he said he thought that after he reached the thick atmosphere, he had deliberately put the ship into a spin.
“A spin is something I know how to get out of,” he said. “That other business— the tumble—there is no way to figure that out.”
. . . Yeager received many accolades. I didn’t begrudge him one of them. If ever a pilot deserved praise for a job well done, it was Yeager. After that X-1A episode, he never flew a rocketplane again.
—Always Another Dawn: The Story of a Rocket Test Pilot, by A. Scott Crossfield with Clay Blair, Jr., The World Publishing Company, Cleveland and New York, Chapter 19 at Pages 183–184.
The Bell X-1A, 48-1384, was an experimental rocket-powered high-speed, high-altitude research aircraft. It was one of four second-generation X-1s (including the X-1B, X-1D and X-1E), specifically designed to investigate dynamic stability at speeds in excess of Mach 2 and altitudes greater than 90,000 feet. It was a mid-wing monoplane with retractable tricycle landing gear. The airplane was 35 feet, 6.58 inches (10.835 meters) long with a wingspan of 30 feet, 6 inches (9.296 meters) and overall height of 10 feet, 2.37 inches (3.261 meters). The wheelbase, measured from the nose wheel axle to the main wheel axle, was 13 feet, 5.13 inches. (4.093 meters). The main wheel tread was 4 feet, 3 inches (1.295 meters). The X-1A design gross weight was 10,668 pounds (4,839 kilograms).
The X-1A was powered by a single Reaction Motors XLR11-RM-5 rocket engine with four independent combustion chambers. The XLR11 was fueled with ethyl alcohol and liquid oxygen. It produced 6,000 pounds of thrust (26.689 kilonewtons).
The Bell X-1A made its first flight 14 February 1953 with Bell test pilot Jean Ziegler in the cockpit. It reached its highest speed, Mach 2.44 on Flight 10. Its highest altitude was 90,440 feet (27,566 meters) on its 24th flight. On 8 August 1955, while still on board its B-50 drop ship, the X-1A suffered an external explosion. The rocketplane was jettisoned and destroyed when it hit the desert floor.
13 November 1942: Lieutenants Harold E. Comstock and Roger B. Dyar were fighter pilots assigned to the 63rd Fighter Squadron, 56th Fighter Group, at Bridgeport, Connecticut. They were often sent to test new P-47 Thunderbolt fighters at the Republic Aviation Corporation factory in nearby Farmingdale, New York:
Because of the need to manufacture airplanes quickly and the close proximity to the Republic Aviation factory, active duty pilots were used for some of the test flights of the new P-47. On 13 November 1942, Lts. Comstock and Dyar were ordered to test a new type of radio antenna on the P-47C. Lt. Comstock climbed to an indicated altitude of 49,600 feet (15,118 meters) while trying to reach 50,000 feet. Due to poor response from the controls, he decided to let the aircraft fall off rather than risk a spin. He started to dive straight down and after passing below 40,000 feet he found that his controls had frozen. He then felt a bump and was unable to move the controls as the aircraft continued to dive. Even with maximum exertion, he was unable to move the control stick so he started to roll the trim tab back and after passing below 30,000 feet, the aircraft started to pull out of the dive and he recovered between 20,000 and 25,000 feet.
Lt. Dyar started his dive and encountered the same conditions. After landing, Lt. Comstock reported what happened and the chief designer of the P-47 Thunderbolt, Alexander Kartveli, questioned Lt. Comstock at length and made numerous calculations. Republic Aviation soon issued a press release claiming that Lts. Comstock and Dyar had exceeded the speed of sound. This was picked up in the national media and also drawn in Ripley’s Believe It or Not!. Soon after the press release, the 56th Fighter Group received a telegram from Gen. Henry “Hap” Arnold that “there would be no more discussion about the dive.” The actual speed attained was probably less than the speed of sound but this speed which caused the flight controls to lock up was referred to as “compressibility.” This effect was encountered by many pilots flying in combat but training and proper procedures allowed them to recover from it. In 1959, the Air Force published “A Chronology of American Aerospace Events” and included an entry for 15 November 1942 which stated “Lts. Harold Comstock and Roger Dyar set a new speed record for airplanes when they power-dived their P-47 fighters at 725 mph from 35,000 feet over an east coast air base.” While the Air Force acknowledged the speed of 725 miles per hour, it is not known whether the P-47 could actually exceed the speed of sound in a dive. Capt. Roger Dyar was killed in action on 26 June 1943. — Wikipedia
Almost certainly, the diving Thunderbolts did not exceed the speed of sound:
In July 1944 Major [Frederic Austin] Borsodi [Chief, Fighter Test Branch, Army Air Forces Material Command, Wright Field] made a number of full power vertical dives from 40,000 feet in a North American P-51D to assess the compressibility effects on the aircraft’s handling. He achieved a maximum Mach number of 0.86, at which point severe buffeting of the empennage was noted. . . many World War II pilots remained firmly convinced that they had taken their propeller-driven fighters supersonic in steep dives, often as local shock waves rattled their craft and caused the angle of those dives to become uncontrollably steeper. More often than not the center of lift moved aft on their wings, and Mach-induced turbulence blanketed the normal control surfaces on the tail. For the lucky ones, the descent into denser air slowed the airplane, while the higher temperatures at lower altitude meant that the Mach number for a given true airspeed was lower. Consequently, local shock waves tended to disappear. A normal recovery as from any steep dive, could usually be effected. . . the later [Supermarine] Spitfires, with a demonstrated ceiling of 45,000 feet, a much thinner wing of elliptical planform, and a lower profile liquid-cooled engine, could never register a maximum speed greater than 0.9 Mach number. That is the highest recorded speed, by a substantial margin of any propeller driven fighter. Oh yes, in the course of one such dive, on entering the denser air around 20,000 feet, the Spitfire’s propeller and much of the engine cowling parted company with the rest of the aircraft. Getting to 0.90 Mach number wasn’t easy. . . the speed of sound at sea level and 59° Fahrenheit is 761 miles per hour. At an altitude of 40,000 feet, where our standard atmosphere charts tell us that the temperature is -67° Fahrenheit, sound travels at 662 miles per hour.
— Aces Wild: The Race For Mach 1, by Al Blackburn, Scholarly Resources, Inc., Wilmington, Delaware, at Pages 6–7, 24–27.
Harold Comstock flew two combat tours in Europe with the 56th Fighter Group during World War II. He completed his second tour as commanding officer of the group’s 63rd Fighter Squadron. He flew 138 combat missions and is officially credited with destroying 5 enemy aircraft in aerial combat, with 2 probably destroyed and 3 damaged, and another 3 destroyed on the ground.
During the Vietnam War, Lieutenant Colonel Comstock commanded the 481st Tactical Fighter Squadron, 27th Tactical Fighter Wing from 1965 to 1968. He flew another 132 combat missions in the North American Aviation F-100D Super Sabre, and 38 as commander of an airborne command and control unit of the 7th Airborne Command and Control Squadron.
Colonel Comstock retired from the Air Force in 1971. He was twice awarded the Legion of Merit, and he held the Distinguished Flying Cross with six Oak Leaf Clusters, a Purple Heart, and 17 Air Medals.
Harold E. Comstock died at Clovis, California in 2009.
The Republic P-47 Thunderbolt was the largest single-engine fighter that had yet been built. The first P-47C variant was completed 14 September 1942, only one month before Bunny Comstock’s famous dive. An early change (P-47C-1) was the addition of 8 inches (0.203 meters) to the forward fuselage for improved handling. The P-47C-5-RE was 36 feet, 1-3/16 inches (11.003 meters) long with a wingspan of 40 feet, 9-5/16 inches (12.429 meters) The overall height was 14 feet 3-5/16 inches (4.351 meters). The fighter’s empty weight was 9,900 pounds (4,490.6 kilograms) and maximum gross weight was 14,925 pounds (6,769.9 kilograms).
The P-47C was powered by an air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter) Pratt & Whitney Double Wasp TSB1-G (R-2800-21) two-row, 18-cylinder radial engine with a compression ratio of 6.65:1. The R-2800-21 had a Normal Power rating of 1,625 horsepower at 2,550 r.p.m. to 25,000 feet (7,620 meters) and a Takeoff/Military Power rating of 2,000 horsepower at 2,700 r.p.m. to an altitude of 25,000 feet (7,620 meters). A large General Electric turbosupercharger was mounted in the rear of the fuselage. Internal ducts carried exhaust gases from the engine to drive the turbocharger and the supercharged air was then carried forward to supply the engine. The engine drove a 12 foot, 2 inch (3.708 meter) diameter four-bladed Curtiss Electric propeller through a 2:1 gear reduction. The R-2800-21 was 6 feet, 3.72 inches (1.923 meters) long, 4 feet, 4.50 inches (1.340 meters) in diameter, and weighed 2,265 pounds (1,027 kilograms). Approximately 80% of these engines were produced by the Ford Motor Company. It was also used as a commercial aircraft engine, with optional propeller gear reduction ratios.
The P-47C had a maximum speed in level flight of 433 miles per hour (697 kilometers per hour) at 30,000 feet (9,144 meters). The service ceiling was 42,000 feet (12,802 meters), and it could climb to 15,000 feet (4,572 meters) in 7 minutes, 12 seconds. It had a maximum range of 1,250 miles (2,012 kilometers) with external fuel tanks.
The Thunderbolt was armed with eight Browning AN-M2 .50-caliber machine guns, four in each wing, with 3,400 rounds of ammunition. It could also carry external fuel tanks, rockets and bombs. The structure of the P-47 could be described as “robust” and it was heavily armored.
602 P-47Cs were built in the five months before the P-47D entered production. A total of 15,683 Thunderbolts were built; more than any other Allied fighter type. In aerial combat it had a kill-to-loss ratio of 4.6:1. The amount of damage that the airplane could absorb and still return was remarkable. The P-47, though, really made its name as a ground attack fighter, destroying aircraft, locomotives, rail cars, and tanks by the many thousands. It was one of the most successful aircraft of World War II.
16 October 1963: Operation Greased Lightning. Major Sidney J. Kubesch, Major John Barrett and Captain Gerard Williamson flew from Tokyo, Japan, to London England, non-stop, in 8 hours, 35 minutes, 20.4 seconds. Their airplane was a Convair B-58A-20-CF Hustler, serial number 61-2059, named Greased Lightning. It was assigned to the 305th Bombardment Wing, 19th Air Division, at Bunker Hill Air Force Base, Indiana.
Five inflight refuelings were required to complete the flight. The bomber had to slow from its supersonic cruise to rendezvous with the tankers. The B-58’s average speed was 692.71 miles per hour (1,114.81 kilometers per hour). The speed from Tokyo to Anchorage, Alaska was 3 hours, 9 minutes, 42 seconds at an average 1,093.4 miles per hour (1,759.7 kilometers per hour); and speed from Anchorage to London, 5 hours, 24 minutes, 54 seconds at 826.9 miles per hour (1.330.8 kilometers per hour).
Greased Lightning‘s speed record still stands.
The three crewmen were awarded the Distinguished Flying Cross.
The B-58 Hustler was a high-altitude Mach 2 strategic bomber which served with the United States Air Force from 1960 to 1970. It was crewed by a pilot, navigator/bombardier and a defensive systems operator located in individual cockpits. The aircraft is a delta-winged configuration similar to the Convair F-102A Delta Dagger and F-106 Delta Dart supersonic interceptors.
The Hustler is 96 feet, 10 inches (29.515 meters) long, with a wing span of 56 feet, 10 inches (17.323 meters) and an overall height of 31 feet 5 inches (9.576 meters). The wing’s leading edge is swept back at a 60° angle and the fuselage incorporates the “area rule” which resulted in a “wasp waist” or “Coke bottle” shape for a significant reduction in aerodynamic drag. The airplane’s only control surfaces are two “elevons” and a rudder, and there are no flaps.
The B-58A was powered by four General Electric J79-GE-5 axial-flow afterburning turbojet engines, suspended under the wings from pylons. This was a single-shaft engine with a 17-stage compressor and 3-stage turbine, rated at 10,300 pounds of thrust (45.82 kilonewtons), and 15,600 pounds (69.39 kilonewtons) with afterburner. The J79-GE-5 was 16 feet, 10.2 inches (5.136 meters) long and 3 feet, 2.0 inches (0.965 meters) in diameter.
The bomber had a cruise speed of 610 miles per hour (981.7 kilometers per hour) and a maximum speed of 1,325 miles per hour (2,132.4 kilometers per hour). The service ceiling is 64,800 feet (19,751 meters). Unrefueled range is 4,400 miles (7,081 kilometers). Maximum weight is 168,000 pounds (76,203.5 kilograms).
The B-58 weapons load was a combination of a W-39 warhead, and/or Mk.43 or B61 nuclear bombs. The W-39 warhead, the same used with the Redstone IRBM or Snark cruise missile, was carried in a jettisonable centerline pod, which also carried fuel for the aircraft. The smaller bombs were carried on underwing hardpoints. For defense, there was a General Electric M61 Vulcan 20×102 mm six-barreled rotary cannon mounted in the tail, with 1,200 rounds of linked ammunition, controlled by the Defensive Systems Officer.
Convair B-58A-20 CF 61-2059 is in the collection of the Strategic Air and Space Museum, Ashland, Nebraska.
14 October 1997: On the Fiftieth Anniversary of his historic supersonic flight in the Bell X-1 research rocketplane, Brigadier General Charles Elwood (“Chuck”) Yeager, United States Air Force (Retired) once again broke the Sound Barrier when he flew over Edwards Air Force Base in a McDonnell Douglas F-15D-38-MC Eagle, serial number 84-046. Lieutenant Colonel Troy Fontaine flew in the rear seat of the two-place fighter. Glamorous Glennis III was painted on the Eagle’s nose.
An estimated 5,000 spectators were at Edwards Air Force Base in the high desert north of Los Angeles, California, to see this historic flight.
My friend, aviation photographer Tim Bradley, and I were there. Tim took the photograph above a few minutes after General Yeager landed. As he concluded his comments to the crowd, he said, “All that I am. . . I owe to the Air Force.”