Daily Archives: November 13, 2017

13 November 1942

Two Republic Aviation Corporation P-47C Thunderbolts of the 56th Fighter Group retract their landing gear after takeoff. (U.S. Air Force)
Two Republic Aviation Corporation P-47C Thunderbolts of the 56th Fighter Group retract their landing gear after takeoff. (U.S. Air Force)

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:

Lieutenant Harold E. Comstock, U.S. Army Air Corps, with his P-47 Thunderbolt, 1943.

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 instrument panel of a Republic P-47D-40-RA Thunderbolt in the collection of the National Museum of the United States Air Force. The Airspeed Indicator is in the second row of instruments, just left of center. Note that the maximum speed marked on the face of the gauge is 700 miles per hour. (U.S. Air Force)
The instrument panel of a Republic P-47D-40-RA Thunderbolt in the collection of the National Museum of the United States Air Force. The Airspeed Indicator is in the second row of instruments, just left of center. Note that the maximum speed marked on the face of the gauge is 700 miles per hour. (U.S. Air Force)

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.

Captain Harold E. Comstock, United States Army Air Corps. (U.S. Air Force)
Captain Harold E. Comstock, United States Army Air Corps, 1944. (U.S. Air Force)

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.

Lieutenant Colonel Harold E. Comstock, U.S. Air Force, 481st Tactical Fighter Squadron, 26th Tactical Fighter Wing, with a North American Aviation F-100D-26-NA Super Sabre, 55-3623, at Cannon Air Force Base, New Mexico, 1964. (Jet Pilot Overseas)
Lieutenant Colonel Harold E. Comstock, U.S. Air Force, 481st Tactical Fighter Squadron, 26th Tactical Fighter Wing, with a North American Aviation F-100D-26-NA Super Sabre, 55-3623, at Cannon Air Force Base, New Mexico, 1964. (Jet Pilot Overseas)

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.

Republic P-47D-6-RE Thunderbolt 42-74742 at RAF Duxford during World War II. The maintenance technicians show the fighter's enormous size. (Daily Mail)
Republic P-47D-6-RE Thunderbolt 42-74742 at RAF Duxford during World War II. The four maintenance technicians show the fighter’s enormous size. (Daily Mail)

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.

UN Y, Bunny Comstock's P-47C-5-RE Thunderbolt 41-6326. (U.S. Air Force)
UN Y, Bunny Comstock’s Republic P-47C-5-RE Thunderbolt 41-6326. (U.S. Air Force)
Colonel Comstock's Republic P-47C-5-RE Thunderbolt 41-6326 after a crash landing at Beccles, Suffolk, England, 3 February 1944. (U.S. Air Force)
Low on fuel after a combat mission, Lieutenant Comstock’s Republic P-47C-5-RE Thunderbolt 41-6326  crashed at Lyons Farm, Mutford, Suffolk, England, 3 February 1944. (U.S. Air Force)

© 2016, Bryan R. Swopes

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13 November 1926

Regia Aeronautica Macchi M.39, MM.76, winner of the 1926 Schneider Trophy Race. (U.S. Air Force)
Regia Aeronautica Macchi M.39, MM.76, winner of the 1926 Schneider Trophy Race. (U.S. Air Force)
Colonel Mario de Bernardi, Regia Aeronautica
Colonel Mario de Bernardi, Regia Aeronautica

13 November 1926: The 1926 race for the Coupe d’Aviation Maritime Jacques Schneider (the Schneider Trophy) was held at Hampton Roads, a large natural harbor between southeastern Virginia and northeastern North Carolina, two states on the Atlantic coast of the United States. There were an estimated 30,000 spectators. The race consisted of seven laps of a 50 kilometer (31 miles) triangular course.

The location of each race went to the country whose national team had won the previous year. Lieutenant James H. Doolittle, Air Service, United States Army, had won the 26 October 1925 race at Baltimore, Maryland, flying a Curtiss R3C-2 to an average speed of 232.57 miles per hour (374.29 kilometers per hour).

The 1926 Schneider Race included three Italian and three American airplanes. The British team’s aircraft were not ready so they did not compete.

Captain,Arturo Ferrin, Regia Aeronautica (1895–1941)
Captain Arturo Ferrarin, Regia Aeronautica (1895–1941)

All three Regia Aeronautica pilots, Major Mario de Bernardi, Captain Arturo Ferrarin, and Lieutenant Adriano Bacula, flew Macchi M.39 seaplanes, powered by the Fiat AS.2 V-12 engine.

The American team used three different Curtiss biplanes, each with a different Curtiss V-12 engine. 1st Lieutenant Christian Frank Schilt, United States Marine Corps, flew a Curtiss R3C-2, serial number A.7054, carrying race number 6. Schilt’s airplane was powered by a Curtiss V-1400. Lieutenant William Gosnell Tomlinson, U.S. Navy, flew a Curtiss F6C-3 Hawk, A.7128, with race number 2. This airplane was equipped with a Curtiss D-12A. Lieutenant George T. Cuddihy, U.S. Navy, flew a Curtiss R3C-4, A.6979, with race number 4, with a Curtiss V-1550.

Christian Frank Schilt in the cockpit of the Curtis R3C-2 racer, number 6. (National Air and Space Museum, Smithsonian Institution)
1st Lieutenant Christian Frank Schilt, U.S. Marine Corps, in the cockpit of the Curtis R3C-2 racer, A.7054, race number 6. (National Air and Space Museum, Smithsonian Institution)
The Italian team celebrates their victory (Virginia Aviation) by Roger Connor at Page 42

The race was delayed for two days because of adverse weather conditions. The race began at 2:35 p.m. on Saturday afternoon, with the first of three Italian racers entering the course.  Airplanes departed at intervals to avoid coming too close to each other while flying the course.

De Bernardi finished the seven laps in 52 minutes, 56.22 seconds, averaging 246.496 miles per hour (396.697 kilometers per hour). Schilt finished in second place in 56 minutes, 23.96 seconds, at 231.364 miles per hour (372.344 kilometers per hour). Bacula was third at 59 minutes, 51.31 seconds, at 218.006 miles per hour (350.847 kilometers per hour). Fourth place went to Tomlinson, completing the course in 1 hour, 35 minutes, 16.72 seconds, at 136.954 miles per hour (220.406 kilometers per hour). Ferrarin’s airplane had an oil line break and he made a precautionary landing at the end of his fourth lap. A fuel pump on Cuddihy’s airplane failed, and his engine stopped. He touched down short of the finish line on his seventh and final lap.

Aeronautica Macchi M.39, circa 1926. (Unattributed)
Aeronautica Macchi M.39 at Lago di Varese, August 1926. (Unattributed)

The Macchi M.39 racing float plane was designed by Mario Castoldi. It is a single engine, single-place, low-wing monoplane with two pontoons, or floats. The wing is externally braced, has 0° dihedral, and incorporates surface radiators. The M.39 is 6.473 meters (22 feet, 2.8 inches) long with a wingspan of 9.26 meters (30 feet, 4.6 inches) and height of 3.06 meters (10 feet, 0.5 inches). The empty weight of the Schneider Trophy racer is 1,300 kilograms (2,866 pounds) and its maximum gross weight is 1,615 kilograms (3,560 pounds).

The M.39 is powered by a water-cooled, normally-aspirated, 31.403 liter (1,916.329 cubic inch) Fiat AS.2 DOHC 60° V-12 direct-drive engine with a compression ratio of 6:1. It used three carburetors and two magnetos, and produced 882 horsepower at 2,500 r.p.m. The engine drove a two-bladed, fixed-pitch metal propeller designed by Dr. Sylvanus A. Reed. The AS.2 engine was designed by Tranquillo Zerbi, based on the Curtiss Aeroplane and Motor Company’s D-12 engine. The engine was 1.864 meters (6 feet, 1.4 inches) long, 0.720 meters (2 feet, 4.4 inches) wide and 0.948 meters (3 feet, 1.3 inches) high. It weighed 412 kilograms (908 pounds).

The Macchi M.39 could reach 420 kilometers per hour (261 miles per hour).

Macchi M.39 MM.76 is in the collection of the Aeronautica Militare museum.

Macchi M.39 MM.76 (Bergefalke2/Wikipedia)
Macchi M.39 MM.76 (Bergefalke2/Wikipedia)

Mario de Bernardi served in the Italian Army during the Italo-Turkish War, 1911–1912, and became a pilot during World War I. He rose to the rank of colonel in the Regia Aeronautica. He set several world aviation records and continued his work as a test pilot. He died in 1959 at the age of 65 years.

Adriano Bacula also set several world records. He was killed in an airplane crash in Slovenia, 18 April 1938.

Arturo Ferrarin, another world record holder, was killed while testing an experimental airplane, 18 July 1941.

Christian Frank Schilt enlisted as a private in the U.S. Marine Corps in 1917. He was awarded the Medal of Honor for his actions in Nicaragua, 6–8 January 1928. During World War II, Schilt served as Commander, Marine Air Group 11 during the Solomons Campaign, and later went on to command Aircraft, Fleet Marine Force, Pacific. He retired from the Marine Corps with the rank of General in 1957, and died in 1987 at the age of 91 years.

William Gosnell Tomlinson was a 1919 graduate of the United States Naval Academy. During his career in the U.S. Navy, he commanded the aircraft carrier USS Belleau Wood (CVL-24), Carrier Division 3, USS Boxer (CVA-21), USS Bon Homme Richard (CVA-31) and served as Commander, Task Force 77 (CTF 77) during the Korean War. During World War II, Tomlinson was awarded the Navy Cross, and twice, the Legion of Merit with Combat “V”. He retired in 1953 as a Vice Admiral, and died in 1972 at the age of 75 years.

George T. Cuddihy was a 1918 graduate of the U.S. Naval Academy. he was the Navy’s chief test pilot. He was killed while testing a Bristol Type 105 Bulldog II fighter, Bu. No. A8485 (c/n 7358) at Anacostia Naval Air Station, 25 November 1929.

© 2017, Bryan R. Swopes

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