11 December 1959: Brigadier General Joseph H. Moore, U.S. Air Force, Wing Commander, 4th Tactical Fighter Wing at Seymour Johnson Air Force Base, North Carolina, set a Fédération Aéronautique Internationale (FAI) World Speed Record when he flew a Republic F-105B-20-RE Thunderchief, serial number 57-5812, over a closed 100-kilometer (62.137 miles) closed course at Edwards Air Force Base, California. The Thunderchief averaged 1,878.67 kilometers per hour (1,167.35 miles per hour).¹ General Moore’s fighter bomber was a standard production aircraft and it was armed with a full load of ammunition for the M61 cannon.
FAI Record File Num #8873 [Direct Link]
Status: ratified – retired by changes of the sporting code
Class: C (Powered Aeroplanes)
Sub-Class: C-1 (Landplanes)
Category: Not applicable
Group: 3 : turbo-jet
Type of record: Speed over a closed circuit of 100 km without payload
Performance: 1 878.67 km/h
Course/Location: Edwards AFB, CA (USA)
Claimant Joseph H. Moore (USA)
Aeroplane: Republic F-105B
Engine: 1 Pratt & Whitney J-75
The F-105 was the largest single-seat, single-engine combat aircraft in history. It was designed as a tactical nuclear strike aircraft and fighter-bomber. The fuselage of the F-105B incorporated the “area rule” which gave the Thunderchief its characteristic “wasp waist” shape. The Thunderchief was 63 feet, 1 inch (19.228 meters) long with a wingspan of 34 feet, 11 inches (10.643 meters). It was 19 feet, 8 inches high (5.994 meters). wings were swept 45° at 25% chord. The angle of incidence was 0° and there was no twist. The wings had 3° 30′ anhedral. The total wing area was 385 square feet (35.8 square meters). The F-105 had an empty weight of 25,855 pounds (11,728 kilograms) and a maximum takeoff weight of 50,000 pounds (22,680 kilograms).
Early production F-105Bs had the Pratt & Whitney J75-P-5 axial-flow turbojet engine. Beginning with the Block 20 aircraft, the more powerful J75-P-19 was installed. The -19 engine was retrofitted to the earlier aircraft. The Thunderchief was powered by one Pratt & Whitney J75-P-19W engine. The J75 is a two-spool axial-flow afterburning turbojet with water injection. It has a 15-stage compressor section (8 low- and and 7 high-pressure stages) and 3-stage turbine section (1 high- and 2 low-pressure stages.) The J75-P-19W is rated at 14,300 pounds of thrust (63.61 kilonewtons), continuous power; 16,100 pounds (71.62 kilonewtons), Military Power (30-minute limit); and Maximum Power rating of 24,500 pounds (108.98 kilonewtons) with afterburner (15-minute limit). The engine could produce 26,500 pounds of thrust (117.88 kilonewtons) with water injection, for takeoff. The J75-P-19W is 21 feet, 7.3 inches (6.586 meters) long, 3 feet, 7.0 inches (1.092 meters) in diameter, and weighs 5,960 pounds (2,703 kilograms).
Armament consisted of one 20 mm General Electric M61 Vulcan six-barreled Gatling gun with 1,080 rounds of ammunition. It had an internal bomb bay and could carry bombs, missiles or fuel tanks on under wing and centerline hardpoints. The maximum bomb load consisted of four 750-pound (340 kilogram) bombs. For tactical nuclear strike missions, the F-105B could carry one Mk-28 “special store” in the internal bomb bay.
The F-105B had a maximum speed of 737 knots (848 miles/1,364 kilometers per hour) at Sea Level, and 1,204 knots (1,386 miles per hour/2,230 kilometers per hour) at 35,000 feet (10,668 meters). The service ceiling was 45,700 feet (13,929 meters). Maximum range was 2,006 nautical miles (2,308 statute miles/3,715 kilometers).
Republic Aircraft Corporation built 833 Thunderchiefs for the U.S. Air Force. 75 of those were F-105Bs. 372 F-105s were lost to enemy action in South East Asia.
Republic F-105B-20-RE Thunderchief 57-5812 served with the 119th Tactical Fighter Squadron, New Jersey Air National Guard, and was later assigned to the 466th Tactical Fighter Squadron, 508th Tactical Fighter Wing at Hill Air Force Base, Utah. One source indicates that the the record-setting F-105B was used as a battle damage repair trainer at McClellan Air Force Base, Sacramento, California, from October 1980.
¹ Many sources cite General Moore’s World Record Speed for the 100-kilometer closed course at 1,216.48 miles per hour (1,957.745 kilometers per hour). The FAI’s official web site gives General Moore’s speed as 1,878.67 kilometers per hour (1,167.35 miles per hour). (See above.) Also, many sources (including General Moore’s official Air Force biography) state that General Moore won the Bendix Trophy for this flight. The Bendix Trophy was awarded to the winner of an annual West-to-East transcontinental air race. The Smithsonian Institution indicates that the Bendix Trophy was not awarded for the years 1958, 1959 or 1960.
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. According to Wikipedia:
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
The Los Angeles Times reported:
Plane Diving 725 m.p.h. Surpasses Speed of Sound
Bulletlike, 12-Mile-Minute Plunge of Thunderbolt P-47 Froze Control Sticks, Intrepid Army Pilots Report
Farmingdale, N.Y., Dec. 2. (AP)—How two Army lieutenants dived their Republic P-47 Thunderbolt fighter plane at a speed of 725 miles an hour—more than 12 miles a minute and faster than the high-altitude speed of sound—was disclosed today.
The terrific speed—perhaps faster than any human being has traveled before—froze their control sticks, the pilots reported, causing them to resort to the use of emergency cranks to move the elevator tabs and pull their ships out of the dive.
“My body was pushed back against the rear armor plate and I had a feeling that any second the plane was going to pull away from me and leave me stranded right there, five miles above the ground. It;s a breathless feeling, your stomach curls up; it’s something like stepping from a hot shower to a cold one,” Lieut. Roger Dyar, one of the pilots, said.
“When I rolled back on the tabs,” Lieut. Harold Comstock said, “the plane shuddered as though it had been hit by a truck.”
Both pilots became air cadets in 1941. Lieut. Comstock is from Fresno, Cal., and Lieut. Dyar from Lowell, O.
—Los Angeles Times, Vol. LXI, Thursday, 3 December 1942, Page 1, Columns 4 and 5
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 Elwood Comstock was born 20 December 1920 at Fresno, California. He was the son of Clinton Elwood Comstock, a telephone company repairman, and Leona M. Sutherland Comstock. He graduated from Roosevelt High School in Fresno, in February 1939. Comstock then entered Fresno State College. He was a member of the F.S.C. Pilots Club and the Aero Mechanics Club.
Harold Comstock was appointed an Aviation Cadet, Air Corps, Army of the United States (A.U.S.), 10 October 1941. He was 5 feet, 10 inches (1.78 meters) tall and weighed 149 pounds (67.6 kilograms). After completing flight training, on 3 July 1942 Comstock was commissioned as a second lieutenant, Air Reserve. Comstock was promoted to first lieutenant, A.U.S., 29 May 1943. Lieutenant Comstock advanced to the rank of captain, A.U.S., on 12 March 1944, and to major, A.U.S., 17 September 1944. On 3 July 1945, Major Comstock’s permanent Air-Reserve rank was advanced to first lieutenant.
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 his World War II service, Major Comstock was awarded the Distinguished Flying Cross with three oak leaf clusters (four awards); the Air Medal with 11 oak leaf clusters (12 awards) and the Purple Heart.
Lieutenant Comstock married Miss Barbara Lucille Joint, also from Fresno, 10 June 1942 at Bridge City, Texas. They would have two children, Harold Eric Comstock, and Roger Joseph Comstock.
On 16 May 1947, Major Comstock was promoted to the rank of Lieutenant Colonel, Air-Reserve. On 10 October 1947, Comstock’s permanent military rank became fist lieutenant, Air Corps, with date of rank retroactive to 3 July 1945. When the United States Air Force was established as an independent branch of the U.S. Armed Forces, Comstock’s commission was converted. (1st Lieutenant, No. 7779.)
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’s final assignment was as commanding officer, 602nd Tactical Control Group, Bergrstom Air Force Base, southeast of Austin, Texas.
Colonel Comstock retired from the Air Force on 30 September 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 at the age of 88 years. He was buried at Fresno Memorial Gardens, Fresno, California.
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.
22 October 1955: At Edwards Air Force Base, in the high desert of southern California, Republic Aviation Corporation test pilot Russell M. (“Rusty”) Roth took the first of two prototype YF-105A-1-REs, serial number 54-098, for its first flight.
Though equipped with an under-powered Pratt & Whitney J57-P-25 interim engine, the new airplane was able to reach Mach 1.2 in level flight.
Aerodynamic improvements to the engine intakes and redesign of the fuselage to incorporate the drag-reducing “area rule,” along with the more powerful J75-P-5 turbojet engine allowed the production model F-105B to reach Mach 2.15.
The Thunderchief is the largest single-place, single-engine aircraft ever built. It was a Mach 2 fighter-bomber, designed for NATO defensive tactical nuclear strikes with a nuclear bomb carried in an internal bomb bay. The YF-105A was 61 feet, 0 inches (18.593 meters) long, with a wing span of 34 feet, 11 inches (10.643 meters) and overall height of 17 feet, 6 inches (5.334 meters). Its empty weight was 20,454 pounds (9,277 kilograms) and the Maximum Takeoff Weight (MTOW) was 41,500 pounds (18,824 kilograms).
The Pratt & Whitney Turbo Wasp JT3C (J57-P-25) was a two-spool axial-flow turbojet engine with a 16-stage compressor section (9 low- and 7 high-pressure stages) and a 3-stage turbine (1 high- and 2 low-pressure stages). The J57-P-25 had a Normal Power rating of 8,700 pounds of thrust (38.700 kilonewtons), and at Military Power produced 10,200 pounds of thrust (45.372 kilonewtons) (30-minute limit). The Maximum Power rating was 16,000 pounds of thrust (71.172 kilonewtons) with afterburner (5-minute limit). The J57-P-25 was 22 feet, 3.1 inches (6.784 meters) long, 3 feet, 3.8 inches (1.011 meters) in diameter, and weighed 5,120 pounds (2,322 kilograms).
The YF-105A’s wings were swept 45° at 25% chord. The angle of incidence was 0° and there was no twist. The wings had 3° 30′ anhedral. The total wing area was 385 square feet (35.8 square meters).
During testing, the prototype’s maximum speed was 770 knots (886 miles per hour (1,426 kilometers per hour) at 35,000 feet (10,668 meters)—Mach 1.34—and 676 knots (778 miles per hour/1,252 kilometers per hour) at Sea Level—Mach 1.02. The YF-105A’s service ceiling was 52,050 feet (15,865 meters). It’s combat radius was 950 nautical miles (1,093 statute miles/1,759 kilometers), and the maximum ferry range was 2,321 nautical miles (2,671 statute miles/4,298 kilometers).
The Thunderchief was armed with a General Electric T171E2 (M61) 20 mm six-barrel rotary cannon with 1,030 rounds of ammunition. 8,000 pounds (3,629 kilograms) of bombs could be carried in an internal bomb bay or on external hardpoints. A single free-fall B28IN variable-yield thermonuclear bomb could be carried in the bomb bay.
On 16 December 1955, YF-105A 54-098 made an emergency landing at Edwards AFB after one of its main landing gear assemblies was torn off when it failed to retract during a high speed flight. The pilot, Rusty Roth, was severely injured, but he survived. The prototype was shipped back to Republic for repair, but the cost was determined to be prohibitive.
Though designed for air-to-ground attack missions, F-105s are officially credited with 27.5 victories in air combat.
833 Thunderchiefs were built by Republic between 1955 and 1964. 334 of those were lost to enemy action during the Vietnam War. The F-105 remained in service with the United States Air Force until 1980, and with a few Air National Guard units until 1983.
The President of the United States of America, authorized by Title 10, Section 8742, United States Code, takes pleasure in presenting the Air Force Cross to Colonel Robert M. White (AFSN: 0-24589A), United States Air Force, for extraordinary heroism in military operations against an opposing armed force as an F-105 Mission Commander and Pilot of the 355th Tactical Fighter Wing, Takhli Royal Thai Air Base, Thailand, in action near Hanoi, North Vietnam, on 11 August 1967. On that date, Colonel White led the entire combat force against a key railroad and highway bridge in the vicinity of Hanoi. In spite of 14 surface-to-air missile launches, MiG interceptor attacks, and intense anti-aircraft artillery fire, he gallantly led the attack. By being the first aircraft to dive through the dark clouds of bursting flak, Colonel White set an example that inspired the remaining attacking force to destroy the bridge without a single aircraft being lost to the hostile gunners. Through his extraordinary heroism, superb airmanship, and aggressiveness in the face of hostile forces, Colonel White reflected the highest credit upon himself and the United States Air Force.
Action Date: 11-Aug-67
The President of the United States of America, authorized by Title 10, Section 8742, United States Code, takes pleasure in presenting the Air Force Cross to Lieutenant Colonel Harry W. Schurr (AFSN: 0-41901), United States Air Force, for extraordinary heroism in connection with military operations against an opposing armed force as commander of a strike force of twenty F-105 Thunderchiefs of the 469th Tactical Fighter Squadron, 388th Tactical Fighter Wing, Korat Royal Thai Air Base, Thailand, in action against a heavily defended target in North Vietnam on 11 August 1967. On that date, though intense, accurately directed hostile fire had damaged his aircraft prior to reaching the target, Colonel Schurr, with undaunted determination, indomitable courage, and professional skill, led the strike in a devastating attack against a key railroad and highway bridge. One span was destroyed and others heavily damaged. As a result, the flow of war materials into this area was appreciably reduced. Through his extraordinary heroism, superb airmanship, and aggressiveness in the face of the hostile force, Colonel Schurr has reflected the highest credit upon himself and the United States Air Force.
General Orders: Department of the Air Force, Special Order GB-427 (November 30, 1967)