7 December 1936: After its third test flight, the first YB-17 service test aircraft, 36-149, landed back at Boeing Field, Seattle, Washington. The pilot was Lieutenant Colonel Stanley M. Umstead, Air Corps, United States Army, who was considered to be the Army’s most experienced and capable pilot.
When the airplane touched down, the main wheels locked and after skidding a short distance, the B-17 nosed over. The bomber’s brakes had welded. No injuries were reported. 36-149 suffered moderate damage.
Boeing repaired the bomber. On 11 January 1937, the YB-17 was flown to Wright Field, Dayton, Ohio, for continued testing. 36-149 was then assigned to the 2nd Bombardment Group at Langley Field, Virginia, 1 March 1937. In October 1940 the bomber was transferred to the 19th Bombardment Group at March Field, California. On 11 February 1942 it was transferred to the Air Park at Amarillo Army Air Field, a B-17 training base in Texas. 36-149 was written off 11 December 1942.
A contemporary newspaper article reported the incident:
Landing from a test flight in Seattle, Wash., the new 16 ton army bombing plane YB-17 nosed over and was badly damaged. Capt. E.R. McReynolds, an army air corps observer who was aboard, said the air brakes locked, preventing the landing wheels from rolling when the plane touched the ground. It was reported subsequently in Washington, D.C. that the accident might result in suspending construction of 13 bombing planes of similar type pending an investigation. The YB-17, largest land plane ever built in America, was designed to carry a ton of bombs and had a cruising range of 3,000 miles.
—Chicago Sunday Tribune, 13 December 1936, Part 2, Page 8, Column 8.
The YB-17 had several improvements over the Model 299, which had been retroactively designated XB-17. There were long carburetor intakes on the top of the engine nacelles, which visually distinguishes the YB-17 from the follow-on YB-17A. The main landing gear has one strut rather than the two of the Model 299.
The Boeing Model 299B was designated YB-17 by the Army Air Corps. It was 68 feet, 4 inches (20.828 meters) long with a wingspan of 103 feet, 9⅜ inches (31.633 meters) and an overall height of 18 feet, 4 inches (5.588 meters). It had an empty weight of 24,465 pounds (11,097 kilograms), gross weight of 34,880 pounds (15,821 kilograms) and maximum takeoff weight of 42,600 pounds (19,323 kilograms).
Instead of the Pratt & Whitney engines installed on the 299, the YB-17 had four air-cooled, supercharged 1,823.129-cubic-inch-displacement (29.875 liter) Wright Aeronautical Division Cyclone 9 R-1820G5 (R-1820-39) nine-cylinder radial engines with a compression ratio of 6.45:1. The R-1820-39 was rated at 805 horsepower at 2,100 r.p.m., at Sea Level, and 930 horsepower at 2,200 r.p.m., at Sea Level, for takeoff. The engines turned three-bladed Hamilton Standard constant-speed propellers through a 16:11 gear reduction, in order to match the engines’ effective power range with the propellers. The R-1820-39 was 3 feet, 9-7/16 inches (1.154 meters) long, 4 feet, 6-¼ inches (1.378 meters) in diameter, and weighed 1,198 pounds (543.4 kilograms).
The cruise speed of the YB-17 was 217 miles per hour (349 kilometers per hour) and its maximum speed was 256 miles per hour (412 kilometers per hour) at 14,000 feet (4,267 meters). The bomber’s service ceiling was 30,600 feet (9,327 meters) and the maximum range was 3,320 miles (5,343 kilometers).
The YB-17 could carry 8,000 pounds (3,629 kilograms) of bombs. Defensive armament consisted of five .30-caliber air-cooled machine guns.
21 November 1947: Grumman Aircraft Engineering Corporation engineering test pilot Corwin Henry (“Corky”) Meyer took off from the company’s airfield at Bethpage, Long Island, New York, in the first prototype XF9F-2 Panther, Bu. No. 122475. After the preliminary flight evaluation, Meyer landed the new jet fighter on a longer runway at Idlewild Airport. The Bethpage runway was only 5,000 feet (1,524 meters) long. As the first jet aircraft built by Grumman, it wasn’t known if the XF9F-2 could land on that short a runway.
Air & Space/Smithsonian magazine quoted Meyer as saying that the weather was “the foulest of any first flight in my experience.” He described the prototype’s handling qualities: “It handled like a J-3 Cub.” In an article for Flight Journal, Corky Meyer wrote: “I conducted a very satisfactory first flight of the 5,000-pound-thrust Rolls-Royce Nene-powered fighter on November 21, 1947.”
The XF9F-2 Panther was the first jet-powered aircraft to be built by Grumman, a major supplier of aircraft for the United States Navy. It was a single-seat, single-engine, day fighter, designed for operation on the U.S. Navy’s aircraft carriers. It was developed from a proposed four-engine XF9F-1 night fighter. Grumman planned to use the Rolls-Royce RB.41 Nene centrifugal-flow turbojet engine. With 5,000 pounds rated thrust at 12,400 r.p.m., the Nene was more powerful (and more reliable) than any engine manufactured by an American company.
Originally it was planned that the Nene would be licensed for production to the Taylor Turbine Corporation as the J42-TT-2. No J42s were ready, so Taylor supplied Grumman with imported Rolls-Royce engines. The Navy had concerns about Taylor’s capability to produce engine in sufficient quantities and arranged for the J42 license to be sold to Pratt & Whitney.
The Panther was placed into production as the F9F-2. The F9F-2 was 37 feet, 5-3/8 inches (11.414 meters) long with a wingspan of 38 feet, 5⅜ inches (11.719 meters) long, with a wingspan of 38 feet, 0 inches (11.528 meters)—not including wing tanks. Its overall height was 11 feet, 4 inches (3.454 meters). The wings could be hydraulically folded to reduce the span for storage aboard ship. The Panther weighed 9,303 pounds (4,220 kilograms) empty, and had a gross weight of 19,494 pounds (8,842 kilograms.
The F9F-2 was powered by a Pratt & Whitney JT6 (J42-P-8) turbojet engine which produced 5,000 pounds of thrust (22.241 kilonewtons) at Sea Level, and 5,750 pounds (25.577 kilonewtons) with afterburner. The J42 was a license-built version of the Rolls-Royce Nene. The engine used a single-stage centrifugal-flow compressor, 9 combustion chambers and a single-stage axial-flow turbine. The J42-P-8 weighed 1,715 pounds (778 kilograms).
The Panther had a maximum speed of 575 miles per hour (925 kilometers per hour) at Sea Level. Its service ceiling was 44,600 feet (13,594 meters), and the range was 1,353 miles (2,177 kilometers).
The Panther was armed with four M3 20 mm autocannon placed in the nose with 760 rounds of ammunition. It could carry up to 3,000 pounds (1,361 kilograms) of bombs or eight 5-inch (12.7 centimeters) rockets on four hardpoints under each wing.
It was a very successful air-to-air and air-to-ground fighter during the Korean War. On 18 November 1952, Lieutenant Elmer Royce Williams, USN, flying an F9F-5 Panther, Bu. No. 125459, of VF-781 aboard the aircraft carrier USS Oriskany (CVA-34), shot down four of seven Soviet Air Force MiG 15 fighters which had launched from Vladivostok toward Task Force 77. His Panther sustained significant damage from enemy cannon shells. Though he safely returned to his carrier, the fighter, Number 106, was so badly damaged that it was pushed over the side. Lieutenant Royce was awarded the Silver Star for this action. No other pilot has ever shot down four MiG fighters during a single combat action.
The F9F Panther was flown during the Korean War by such famed naval aviators as Ted Williams, and future astronauts John Glenn and Neil Armstrong.
Grumman built 1,358 F9F-2,-3,-4 and -5 Panthers and another 1,392 swept wing F9F-6, -7 and -8 Cougars. Panthers remained in service with the United States Navy until 1958, and Cougars until 1974.
Corwin Henry (“Corky”) Meyer ¹ was born 14 April 1920 at Springfield, Illinois. He was the second of three children of Dr. John Gerhard Meyer, a physician and surgeon, and Betsy Arenia Corwin Meyer.
At the age of 17 years, Corky Meyer learned to fly in the Civilian Pilot Training Program. (This was a federal government-funded program which provided 72 hours of ground school and 35–50 hours of flight training, intended to increase the number of pilots available for civilian aviation.)
Meyer attended Springfield High School, in Springfield. He was a member of the Senior Boys’ Council and the National Honor Society. Meyer graduated from high school in May 1938, then entered the University of Illinois. He studied at the at the Massachusetts Institute of Technology (M.I.T.), Cambridge, Massachusetts, 1942–43.
Meyer was a pilot trainee for Pan American Airways before being employed as an engineering test pilot at the Grumman Aircraft Engineering Corporation at Bethpage, New York.
Meyer’s first project was testing newly-built TBF Avenger torpedo bombers. Later he was was a project test pilot for the F6F Hellcat, F8F Bearcat and F7F Tigercat. (Robert Leicester Hall made the first flights of these airplanes, but Corky Meyer was involved in flight testing of each of them early on.)
Corwin H. Meyer married Miss Dorothy Marjorie Fyfield, 7 April 1945, at Huntington, New York. They would have a daughter, Sandra Louise Meyer, born in 1950, and two sons, John Fyfield Meyer and Peter Meyer.
On 19 May 1952, Corky Meyer took the prototype variable-wing-sweep XF10F-1 Jaguar for its first flight at Edwards Air Force Base, California.
From 1952 to 1954, Meyer was head of Grumman’s flight operations at Edwards Air Force Base in California. In 1954, he became the first civilian airplane pilot to qualify for flight operations aboard U.S. Navy aircraft carriers, when he flew an F9F-6 Cougar to USS Lake Champlain (CVA-39). ²
Corky Meyer made the first flight of the XF9F-9 prototype, Bu. No. 138604, on 30 July 1954, and was able to approach mach 1 in level flight. The XF9F-9 was a completely redesigned F9F Cougar, which incorporated the “wasp-waist” in its area-ruled fuselage. The following year, this type would be redesignated the F11F Tiger.
In 1967, Meyer was appointed vice president of Grumman, and in 1968, he was elected to the board of directors of the Grumman Aerospace Corporation. He became the senior vice president of Grumman Aerospace in 1972. In 1974, Meyer became President of Grumman American Aviation Corp., Savannah, Georgia, a subsidiary which produced light civil airplanes, the Grumman AgCat, and the Gulfstream line of executive jets. Corwin Meyer retired from Grumman in 1978. He later served as chief executive officer of the Enstrom Helicopter Corporation and the Falcon Jet Corporation.
Meyer was an early member of the Society of Experimental Test Pilots. In 1971, he was awarded SETP’s James H Doolittle Award for excellence in technical management or engineering achievement in aerospace technology. In 1999 the National Aeronautic Association selected him for its Elder Statesman Award.
Meyer was the author of Corky Meyer’s Flight Journal, an autobiography published in 2005, by Specialty Press, North Branch, Minnesota.
Corwin Henry Meyer died in Naples, Florida, 1 June 2011, at the age of 91 years.
¹ Lutheran Church birth and baptismal records give Meyer’s name as “Henry Corwin Meyer.”
² On 3 April 1991, TDiA’s author became the only civilian helicopter pilot (at that time, and who was not a former military pilot) to qualify to fly from U.S. Navy warships at sea. The Deck Landing Qualification (DLQ) flights were evaluated by instructors from Helicopter Antisubmarine (Light) Squadron (HSL-31) aboard USS Kincaide (DDG-965), a Spruance-class guided missile destroyer.
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.
7 September 1965: First flight of the prototype Bell Model 209 attack helicopter. Test pilot William Thomas (“Bill”) Quinlan was in command. The duration of the flight was twelve minutes.
The Model 209 was a private venture, built in just seven months and rolled out at Fort Worth, Texas, 2 September 1965. The prototype aircraft combined the drive system, rotors and tail boom of the production UH-1C gunship with a streamlined fuselage which placed the two pilots in tandem.
The prototype was equipped with retractable landing gear which gave the 209 increased speed, but the expense and complexity were enough that this feature was not included on production aircraft.
This helicopter would be developed into the famous AH-1G Huey Cobra.
The second prototype, AH-1G 66-15246, was used by the Army for flight testing at Edwards Air Force Base, California, from 3 April to 21 April 1967.
66-15246 had an overall length of 52 feet, 11.65 inches (16.146 meters) with rotors turning. The fuselage was 44 feet, 5.20 inches (13.433 meters) long, and it was 3 feet, 0 inches (0.914 meters) wide. The HueyCobra had a short “stub wing” with a span of 10 feet, 11.60 inches (3.343 meters). Its angle of incidence was 14°. The wing’s area was 27.8 square feet (2.6 square meters). 66-15426 had an empty weight of 5,516 pounds (2,502 kilograms) and maximum gross weight of 9,500 pounds (4,309 kilograms).
The two-bladed Model 540 “door-hinge” main rotor was 44 feet, 0 inches (13.411 meters) in diameter. The blades had a chord of 2 feet, 3 inches (0.686 meters) and 10° negative twist. The main rotor turned counter-clockwise when viewed from above. (The advancing blade is on the helicopter’s right.) Normal rotor r.p.m. (power on) was 314–324 r.p.m., and power off, 304–339 r.p.m. The minimum transient rotor speed, power off, was 250 r.p.m.
The two blade tail rotor assembly had a diameter of 8 feet, 6 inches (2.591 meters) with a chord of 8.41 inches (0.214 meters). There was no twist. It was mounted on the left side of the pylon in a pusher configuration and turned counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.) The tail rotor pylon was cambered to allow aerodynamic forces in forward flight to “unload” the tail rotor.
The AH-1G was powered by a Lycoming LTC1K-4 (T53-L-13) turboshaft engine rated at 1,400 shaft horsepower, though it was derated to the helicopter’s transmission limit. The T53-L-13 is a two-shaft free turbine with a 6-stage compressor (5 axial-flow stages, 1 centrifugal-flow stage) and a 4-stage axial-flow turbine (2 high-pressure stages, 2 low-pressure power turbine stages). The T53-L-13 is 3 feet, 11.9 inches (1.217 meters) long, 1 foot, 11.0 inches (0.584 meters) in diameter and weighs 549 pounds (249 kilograms).
The speed of the Cobra was effected by the armament configuration, whether “clean,” light or heavy scout, or “heavy hog.” At 5,000 feet (1,524 meters), the cruise speed in the clean configuration was 138.0 knots (158.8 miles per hour, 255.6 kilometers per hour); light scout, 134.0 knots (154.2 miles per hour, 248.2 kilometers per hour); and heavy hog, 127.0 knots (146.2 miles per hour, 235.2 kilometers per hour). The maximum airspeed in level flight was 149.0 knots (171.5 miles per hour, 276.0 kilometers per hour); 144.0 knots (165.7 miles per hour, 266.7 kilometers per hour); and 136.5 knots (157.1 miles per hour, 252.8 kilometers per hour), respectively.
The limiting airspeed (VNE) was 190 knots (KCAS) (219 miles per hour, 352 kilometers per hour) below 3,000 feet (914 meters) density altitude.
In autorotation, the airspeed for the minimum rate of descent was 74.0 knots (85.2 miles per hour, 137.1 kilometers per hour) with the main rotor turning 294 r.p.m., resulting in a rate of descent of 1,750 feet per minute (8.89 meters per second).
The basic armament for the AH-1G Cobra was an Emerson M28 turret which could be equipped with one or two General Electric M134 Miniguns, or a combination of a Minigun with a Philco Ford M129 automatic grenade launcher, or two grenade launchers. Each Minigun was supplied with 4,000 rounds of 7.62 NATO ammunition, while a grenade launcher had 300 rounds of 40 × 53 millimeter high-velocity explosive ammunition.
Four hardpoints on the stub wing could be loaded with M18 7.62 NATO Minigun pods; XM35 pods, containing a short-barreled General Electric XM195 20 millimeter Gatling gun (a variant of the M61 Vulcan); rocket pods with seven or nineteen 2.75-inch unguided rockets.
The prototype Cobra, Bell Model 209 N209J, is in the collection of the U.S. Army Aviation Museum, Fort Rucker, Alabama, as is the second prototype, 66-15246.
7 September 1956: At Edwards Air Force Base, California, test pilot Captain Iven Carl Kincheloe, Jr., U.S. Air Force, flew the Bell X-2 rocketplane, serial number 46-674, to a speed of Mach 1.7 and an altitude of 126,200 feet (38,465 meters). He was the first pilot to fly above 100,000 feet (30,480 meters) and was called “The First of the Spacemen”.
The X-2 was a joint project of the U.S. Air Force and NACA (the National Advisory Committee for Aeronautics, the predecessor of NASA). The rocketplane was designed and built by Bell Aircraft Corporation of Buffalo, New York, to explore supersonic flight at speeds beyond the capabilities of the earlier Bell X-1 and Douglas D-558-2 Skyrocket. In addition to the aerodynamic effects of speeds in the Mach 2.0–Mach 3.0 range, engineers knew that the high temperatures created by aerodynamic friction would be a problem, so the aircraft was built from Stainless Steel and K-Monel, a copper-nickel alloy.
The Bell Aircraft Corporation X-2 was 37 feet, 10 inches (11.532 meters) long with a wingspan of 32 feet, 3 inches (9.830 meters) and height of 11 feet, 10 inches (3.607 meters). Its empty weight was 12,375 pounds (5,613 kilograms) and loaded weight was 24,910 pounds (11,299 kilograms).
The X-2 was powered by a throttleable Curtiss-Wright XLR25-CW-1 rocket engine that produced 2,500–15,000 pounds of thrust (11.12–66.72 kilonewtons) burning alcohol and liquid oxygen. The engine used two rocket chambers and had pneumatic, electrical and mechanical controls. The smaller chamber could produce a maximum 5,000 pounds of thrust, and the larger, 10,000 pounds (22.24 and 44.48 kilonewtons, respectively).
Professor Robert H. Goddard, “The Father of Modern Rocketry,” authorized Curtiss-Wright to use his patents, and his rocketry team went to work for the Curtiss-Wright Rocket Department. Royalties for use of the patents were paid to the Guggenheim Foundation and Clark University. Professor Goddard died before he could also make the move to Curtiss-Wright.
Rather than use its limited fuel capacity to take off and climb to altitude, the X-2 was dropped from a modified heavy bomber as had been the earlier rocketplanes. A four-engine Boeing B-50A Superfortress bomber, serial number 46-011, was modified as the ”mothership.” A second Superfortress, B-50D-95-BO 48-096, was also modified to carry the X-2, and was redesignated EB-50D
The launch altitude was 30,000 feet (9,144 meters). After the fuel was exhausted, the X-2 glided to a touchdown on Rogers Dry Lake at Edwards Air Force Base.
Iven Kincheloe was awarded the Mackay Trophy for this flight. His altitude record remained unbeaten until the X-15 Project.