Tag Archives: Prototype

14 August 1953

Commonwealth Aircraft Corporation CA-26 Sabre A94-101 (Royal Australian Air Force)

14 August 1953: Near Avalon Field, Geelong, Victoria, Australia, Flight Lieutenant William H. Scott, Royal Australian Air Force, the 28-year-old Chief Test Pilot of the Government Aircraft Factories, put the new Commonwealth Aircraft Corporation, Pty. Ltd., prototype into shallow dive from 25,000 feet (7,620 meters) over Port Phillip Bay. This was the new airplane’s sixth test flight. Scott passed 670 miles per hour (1,078 kilometers per hour) and broke the “sound barrier.” A triple sonic boom was heard throughout the Melbourne area.

The aircraft was the CA-26 Sabre, A94-101. The Australian-built Sabre had made its first flight 1 August, also with Flt. Lt. Scott in the cockpit. After about a week there were reports of sonic booms in the area around Melbourne.

CAC Sabre A94-101
Commonwealth Aircraft Corporation CA-26 Sabre A94-101 (Royal Australian Air Force)

Based on the highly successful North American Aviation F-86F Sabre, the C.A.C. variant used a license-built Rolls-Royce Avon RA.7 turbojet with 7,350 pounds of thrust. The Sabre’s fuselage had to be extensively redesigned to allow installation of the new engine. Although it was about the same size as the J47 it replaced, the Avon needed a much larger intake duct. And because it weighed less than the J47, it had to be moved aft to maintain the Sabre’s center of gravity. Only about 40% of the original structure remained.

Other changes were replacing the fighter’s basic armament of six .50-caliber Browning machine guns with two 30 mm ADEN revolver cannon. In testing, it was found that teh muzzle blast of the ADEN cannons could cause the engine to flame out. “Maxim” shock wave baffles were installed to eliminate the problem.

Commonwealth Aircraft Corporation CA-26 Sabre A94-901. (Royal Australian Air Force)

The aircraft, often called the “Avon Sabre,” was put into production as the CA-27 Sabre Mk 30. Twenty-two aircraft were built in the version. With the introduction of the Mark 31, the original Sabres were upgraded to the new standard. Sixty-nine Sabre Mk 32 fighters were built with the Avon 25 engine and increased fuel capacity.

The CA-27 was in service with the Royal Australian Service from 1954 until 1971. Several were transferred to Malaysia and Indonesia and operated for those countries until 1982.

CAC CA-27 Sabre Mk 32 A94-901
Commonwealth Aircraft Corporation CA-27 Sabre Mk 32 A94-901 (RAAF)

The prototype CA-26 Sabre, A94-901, flew with several RAAF squadrons, including the 76 Squadron “Black Panthers” Aerobatic Team, 1961–1965. It was withdrawn from service in 1966. The Sabre was restored by Hawker de Havilland at Bankstown Airport, before being sent to the Historical Aircraft Restoration Society Museum (“HARS”) at Illawarra Regional Airport, south of Sydney, New South Wales, Australia. The airplane is again in the livery of the “Black Panthers.”

A94-901 ias it appeared when assigned to 76 Squadron “Black Panthers,” 1961–1965. (HARS Museum)

© 2018, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

13 August 1976

The prototype Bell 222 hovering in ground effect during its first flight, 13 August 1976. (Bell Helicopter TEXTRON)

13 August 1976: At the Bell Helicopter facility at Arlington, Texas, the prototype Model 222 twin-engine helicopter, registration N9988K, made its first flight. During the 42-minute flight, test pilots Donald Lee Bloom and Louis William Hartwig flew the aircraft through a series of hovering maneuvers and transitions to forward flight. A Bell spokesperson described it as, “One of the most successful prototype flights we’ve ever had.”

The prototype Bell 222 hovering out of ground effect, with landing gear retracted, 13 August 1976. (Bell Helicopter TEXTRON)

The Model 222 (“Two Twenty-Two”) was Bell Helicopter’s first completely new helicopter since the Model 206 JetRanger series. Classified as a light twin, the aircraft was originally powered by two Lycoming LTS101-650C-3 turboshaft engines. The two-blade main rotor was similar in design to that used on the AH-1 Cobra attack helicopters. The first four prototypes were built with a T-tail configuration, but problems discovered early in the test program resulted in a change to the arrangement used in the production version.

Bell Model 222 prototypye, N9988K, in flight. Note T-tail configuration. (Bell Helicopter)
Bell Model 222 prototype, N9988K, in flight. Note T-tail configuration. (Bell Helicopter TEXTRON)

The Bell 222 is used as an executive transport, a utility transport and an aeromedical helicopter. It can carry a maximum of ten persons, and is operated with either one or two pilots. The 222 is certified for Instrument Flight Rules. The standard aircraft has retractable tricycle landing gear but the Model 222UT replaces that with a lighter weight skid gear.

The Bell Model 222 is 47 feet, 6.16 inches (14.482 meters) long with rotors turning. The helicopter has a maximum height of 14 feet, 7.25 inches (4.451 meters) with the forward main rotor blade against its droop stop. The height from ground level to the top of the vertical fin is 11 feet, 0.56 inches (3.367 meters). The helicopter’s maximum width is 11 feet, 4.0 inches (3.454 meters). The empty weight is 4,555 pounds (2,066 kilograms), and the maximum gross weight is 7,848 pounds (3,560 kilograms).

The fifth prototype Bell 222, N222BX (c/n 47005), in the 40′ × 80′ (12.2 × 24.4 meters) wind tunnel at the NASA Ames Research Center, Moffett Field, California. The man at the lower left corner of the image shows scale. (NASA)

The 222’s main rotor mast is tilted 5° forward and 1° 15′ to the left. This contributes to a higher forward air speed and counteracts the helicopter’s translating tendency in a hover.

The two-bladed, underslung, semi-rigid main rotor system rotates counter-clockwise as seen from above (the advancing blade is on the right.)and turns 324 r.p.m at 100% NR. The main rotor has a diameter of 39 feet, 9.0 inches (12.116 meters). The blades have a chord of 2 feet, 4.6 inches (7.264 meters) and are pre-coned 3° 30′. The two-bladed tail rotor is positioned on the left side of the tail boom and turns clockwise as seen from the helicopter’s left (the advancing blade is below the axis of rotation). The tail rotor’s diameter is 6 feet, 6.0 inches (1.981 meters). The blades’ chord is 10.0 inches (0.254 meters).

The Bell 222 was originally powered by two Lycoming LTS101-650C-3 engines. The LTS101 is a compact, light weight, turboshaft engine. The 2-stage compressor section has 1 axial-flow stage and 1 centrifugal-flow stage. The turbine section has 1 high-pressure gas generator stage and 1 low-pressure free power stage. The LTS101-650C-3 was has a maximum continuous power rating of 598 shaft horsepower (446 kilowatts at 49,159 r.p.m. (N1) at Sea Level, and 630 shaft horsepower (470 kilowatts) at 49,638 r.p.m. for takeoff (5-minute limit). The output shaft (N2) turns 9,545 r.p.m. With one engine inoperative (OEI), the -650C-3 is rated at 650 shaft horsepower (485 kilowatts) at 50,169 r.p.m. (30-minute limit), and a maximum 675 shaft horsepower at 50,548 r.p.m. N1/9,784 r.p.m. N2 (2½-minute limit). The LTS101-650C-3 is 1 foot, 10.6 inches (0.574 meters) in diameter, 2 feet,7.3 inches (0.795 meters) long, and has a dry weight of 241 pounds (109 kilograms).

The Bell 222 has a maximum speed of 130 knots. Its hover ceiling is approximately 9,000 feet (2,743 meters). The service ceiling is 12,800 feet (3,901 meters). The maximum range is 324 nautical miles (373 statute miles/600 kilometers).

During early production, problems were experienced with the LTS101 engines, which were also used on the Sikorsky S-76 and the Aérospatiale AS-350D A-Star. This seriously hurt the reputation and sales of all three helicopters. Bell Helicopter’s parent corporation, Textron, bought the Lycoming factory and modernized it in order to improve the engine. (The engine is now owned by Honeywell Aerospace.) Operators began to replace the two Lycoming engines with a pair of Allison 250-C30 turboshafts, and eventually Bell Helicopter modified the aircraft, marketing it as the Model 230. A four-bladed variant with a longer cabin is called the Model 430.

After the test program was completed, the first prototype, N9988K, was used as a static prop on the popular television series, “Airwolf.”

Bell 222 N34NR, an aeromedical helicopter operated by Air Angels, Inc., Bolingbrooke, Illinois. (Photograph courtesy of Chris Hargreaves)
Donald Lee Bloom

Donald Lee Bloom was born in Tulsa, Oklahoma, 23 April 1932. He was the son of Fred Miles Bloom, a telegraph operator for the Standard Oil Company, and Georgia Randolph Bloom.

Don Bloom attended the University of Houston as a Naval Reserve Officers Training Corps (NROTC) midshipman. He graduated in 1955. Bloom was commissioned as a second lieutenant, United States Marine Corps, 15 September 1955. He was assigned to pilot training at NAS Pensacola, Florida.

Lieutenant Bloom was promoted to the rank of first lieutenant, 15 March 1957. He married Miss Anne Marie Carruthers in Los Angeles, California, 5 September 1958. They would have four children, Susan, Stacy, Robert and Todd.

Lieutenant Bloom was released from active duty in 1960, and joined the Kaman Aircraft Corporation as a test pilot. In 1961, began his 29-year career as an experimental test pilot with the Bell Helicopter Company.

The first production Bell OH-58A-BF Kiowa, 68-16687. Don Bloom flight-tested this type in his investigation of Loss of Tail Rotor Effectiveness. (U.S. Army)

In 1984 the Society of Experimental Test Pilots gave its Iven C. Kincheloe Award to Don Bloom for his experimental research into the Loss of Tail Rotor Effectiveness (LTE).

After flying as a test pilot on 187 projects, Don Bloom retired from the Bell Helicopter Corporation in 1990 as Senior Experimental Test Pilot. He then worked for the Federal Aviation Administration Southwest Region as its Designated Engineering Representative Flight Test Pilot, testing aircraft for government certification. During his aviation career, Bloom flew over 14,000 hours in 102 different aircraft.

In 2011, the Federal Aviation Administration presented its Wright Brothers Master Pilot Award to Don Bloom.

Donald Lee Bloom died 18 July 2017 at Grapevine, Texas. He was buried at the Dallas-Fort Worth National Cemetery, Dallas, Texas.

Don Bloom was a project development test pilot for the Bell AH-1G Cobra. (U.S. Army)

Louis William Hartwig was born at Sherman, Iowa, 26 July 1922. He was the son of Lawrence C. Harwig and Alta May Gaughey Hartwig. He attended Bowie High Schoo in Bowie, Texas.

Lou Hartwig enlisted in the United States Army 8 September 1942. (s/n 17119277) He was assigned to the 304th and 902nd Field Artillery Battalions, 77th Infantry Division.

Lou Hartwig married Miss Katherine Elizabeth Healzer, a school teacher, at Rustburg, Virginia, 19 February 1944. They would have a son, Ronald.

Piper L-4 Grasshopper. (Harry S. Truman Library & Museum)

Hartwig was deployed to the Pacific theater of operations, 24 March 1944. He flew a Piper L-4 Grasshopper as an artillery spotter at Guam and Okinawa. He was discharged from his enlistment 18 June 1944, and commissioned a second lieutenant, 19 June 1944 (s/n O-1821011). Lieutenant Hartwig returned to the United States on 21 November 1945. He was released from active duty 24 January 1946.

Lou Hartwig was one of the early students of the Bell Aircraft Corporation’s helicopter flight school at Niagara Falls Airport, New York. The school was for experienced pilots only, and required 10–15 days to complete. Each student received a minimum 22½ flight hours in a Bell Model 47. The cost of the course was $600. Hartwig was then employed as an agriculture “crop dusting” pilot in California.

While spraying insecticide in a field near Sacramento, California, Hartwig was overcome by the poisonous chemicals and lost consciousness. The helicopter struck power lines and crashed. Hartwig was thrown from the cockpit. Crash investigators described the accident as “unsurvivable.” He spent the next 11 months in hospital.

Lou Hartwig was a test pilot for the U.S. Navy’s HSL-1 ASW helicopter. (Bell Aircraft Corporation)

The Bell Helicopter Company hired Hartwig as a test pilot on 15 February 1955. One of his first projects was flight testing the Model 61, the only tandem rotor helicopter ever produced by Bell. It was used as an anti-submarine warfare helicopter by the U.S. Navy, designated HSL-1.

On 31 January 1961, Hartwig set a Fédération Aéronautique Internationale (FAI) World Record for Speed Over a Closed Circuit of 100 Kilometers Without Payload, when he flew a Bell Model 47J Ranger at an average speed of 168.36 kilometer per hour (104.61 miles per hour).¹

On 2 February 1961, Lou Hartwig flew a Bell Model 47G, N967B, to set three more FAI world records: Distance in a Closed Circuit Without Landing, 1,016.20 kilometers (631.44 miles); ² Speed Over a Closed Circuit of 500 Kilometers Without Payload, averaging 119.07 kilometers per hour (73.99 miles per hour); ³ and Speed Over a Closed Circuit of 1,000 Kilometers, 118.06 kilometers per hour (73.36 miles per hour.⁴ The Model 47G had been modified with an additional fuel tank from the earlier Model 47D-1, and curved landing skids from the Model 47J.

The Bell 533, 56-6723, in one of its many configurations. It was flown with two- and four-bladed main rotors, with and without wings, and with and without turbojet engines. (Bell Helicopter Corporation)

Lou Hartwig worked on the U.S. Army’s High Performance Helicopter project. A pre-production YH-40 Iroquois, serial number 56-6723, was modified into a winged and compound helicopter configuration, designated Model 533. Hartwig flew the helicopter to a speed of 274.6 knots (316.00 statute miles per hour/508.56 kilometers per hour). In 1971, the Vertical Flight Society gave its Frederick L. Feinberg Award to Hartwig.

Mrs. Hartwig died 10 February 1989, in San Diego, California. Lou Hartwig married his second wife, Joanne Dunning, in 1990.

Louis William Hartwig died 12 April 2016, at the age of 93 years. He was buried at the Dearborn Memorial Park, Poway, California.

¹ FAI Record File Number 986

² FAI Record File Number 983

³ FAI Record File Number 989

⁴ FAI Record File Number 990

© 2018, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

9 August 1939

Bell XP-39 Airacobra 38-326 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, 9 August 1939. The man at the base of the supports shows scale. (NASA)

9 August 1939: After General Henry H. Arnold had ordered that the prototype Bell Aircraft Corporation XP-39 Airacobra be evaluated in the National Advisory Committee for Aeronautics (NACA) Full-Scale Tunnel at the Langley Memorial Aeronautics Laboratory, Langley Field, Virginia, it was flown there from Wright Field. It was hoped that aerodynamic improvements would allow the prototype to exceed 400 miles per hour (644 kilometers per hour).

NACA engineers placed the full-size airplane inside the large wind tunnel for testing. A number of specific areas for aerodynamic improvement were found. After those changes were made by Bell, the XP-39’s top speed had improved by 16%.

Bell XP-39 Airacobra 38-326 in the NACA Langley Memorial Aeronautical Laboratory Full-Scale Wind Tunnel, Langley Field, Virginia, 9 August 1939. The fuselage has had all protrusions removed. Right profile. (National Aeronautics and Space Administration NACA 18423)

The Bell XP-39 Airacobra was a single-place, single-engine prototype fighter with a low wing and retractable tricycle landing gears. The airplane was primarily built of aluminum, though control surfaces were fabric covered.

As originally built, the XP-39 was 28 feet, 8 inches (8.738 meters) long with a wingspan of 35 feet, 10 inches (10.922 meters). The prototype had an empty weight of 3,995 pounds (1,812 kilograms) and gross weight of 5,550 pounds (2,517 kilograms). Changes recommended by NACA resulted in a recontoured canopy, lengthened the airplane to 29 feet, 9 inches (9.068 meters) and reduced the wing span to 34 feet, 0 inches (10.362 meters). Its empty weight increased to 4,530 pounds (2,055 kilograms) and gross weight to 5,834 pounds (2,646 kilograms).

Bell XP-39 in the NACA wind tunnel at Langley Field. (NASA)
Bell XP-39 Airacobra 38-326 in the NACA wind tunnel at Langley Field. The man at the base of the supports shows scale. (NASA)

The XP-39 was unarmed, but it had been designed around the American Armament Corporation T9 37 mm autocannon, later designated Gun, Automatic, 37 mm, M4 (Aircraft). The cannon and ammunition were in the forward fuselage, above the engine driveshaft. The gun fired through the reduction gear box and propeller hub.

The XP-39 was originally powered by a liquid-cooled, turbosupercharged and supercharged 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-E2 (V-1710-17), a single overhead cam (SOHC) 60° V-12 engine with a compression ratio of 6.65:1. The V-1710-17 had a Maximum Continuous Power rating of 1,000 horsepower at 2,600 r.p.m. at 25,000 feet (7,620 meters), and Takeoff/Military Power rating of 1,150 horsepower at 3,000 r.p.m. at 25,000 feet, burning 91 octane gasoline. The engine was installed in an unusual configuration behind the cockpit, with a two-piece drive shaft passing under the cockpit and turning the three-bladed Curtiss Electric constant-speed propeller through a remotely-mounted 1.8:1 gear reduction gear box. The V-1710-17 was 16 feet, 1.79 inches (4.922 meters) long, including the drive shaft and remote gear box. It was 2 feet, 11.45 inches (0.900 meters) high, 2 feet, 5.28 inches (0.744 meters) wide and weighed 1,350 pounds (612 kilograms).

Bell XP-39B prototype, s/n 38-326, at Bell Aircraft Co., Buffalo, New York

Army Air Corps strategy changed the role of the P-39 from a high-altitude interceptor to a low-altitude tactical strike fighter. The original turbocharged V-1710-17 was replaced with a V-1710-37 (V-1710-E5) engine. The turbosupercharger had been removed, which reduced the airplane’s power at altitudes above 15,000 feet (4,572 meters). The V-1710-37 had a maximum power of 1,090 horsepower at 3,000 r.p.m. at 13,300 feet (4,054 meters). With the NACA-recommended aerodynamic changes and the new engine, the prototype Airacobra was redesignated XP-39B.

A Bell P-39 Airacobra fires all of its guns at night. (U.S. Air Force)

© 2018, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

8 August 1946

Convair XB-36 Peacemaker 42-13570 engine run-up
The prototype Consolidated-Vultee XB-36, 42-13570, stands at the end of the runway with all six engines running. (U.S. Air Force)

8 August 1946: At Fort Worth, Texas, the Consolidated-Vultee Aircraft Corporation XB-36 prototype, 42-13570, made its first flight. Convair test pilots Beryl Arthur Erickson and G.S. “Gus” Green, along with Chief Flight Test Engineer James D. “J.D.” McEachern, were in the cockpit and six other crewmembers were aboard.

Chief Test Pilot Beryl Arthur Erickson. (Convair)

In a 1992 interview published in Code One Magazine, Erickson said that he and his crew had been ready to take off at 5 a.m., but they didn’t get their release until noon. The Texas summer temperature was 100 degrees (37.8 °C.), but inside the cockpit, the temperature was 140° F. (60 °C.) The engines were overheating and the oil pressure was low. When they pushed the throttles forward, the XB-36 accelerated smoothly and lifted off at 110 knots (126.6 miles per hour, 203.7 kilometers per hour). The retired test pilot said, “The XB-36 controlled nicely in the takeoff run and in the transition to steady climb. We flew conservatively with the gear down. The flight was uneventful and lasted thirty-eight minutes.”

The B-36 was the largest and heaviest airplane built up to that time. It was designed as a long-range heavy bomber, able to reach targets on the European continent from the United States and return, should England fall to Nazi Germany during World War II. With the end of the war, its purpose was changed to that of a long range strategic bomber, carrying large nuclear weapons that weren’t even imagined when the design process had begun.

A size comparison between the Convair XB-36 prototype and a Boeing B-29 Superfortress.
A size comparison between a Boeing B-29-55-BA Superfortress, 44-84017, and the Consolidated-Vultee XB-36 prototype. (U.S. Air Force)

The XB-36 had a wing span of 230 feet (70.104 meters), nearly 90 feet longer than that of the B-29 Superfortress that it would replace. It was 162 feet, 1 inch (49.403 meters) long and 46 feet, 8 inches (14.224 meters) to the tip of the vertical fin. The prototype’s empty weight was 131,740 pounds (59,756 kilograms), and it had a maximum gross weight of 276,506 pounds (125,421 kilograms).

The XB-36 was powered by six air-cooled, supercharged, 4,362.49 cubic-inch-displacement (71.489 liter) Pratt & Whitney Wasp Major TSB1P-G (R-4360-25) 28-cylinder four-row radial engines, with a normal power rating of 2,500 horsepower at 2,550 r.p.m. to 5,000 feet (1,524 meters), and 3,000 horsepower at 2,700 r.p.m. for takeoff. They were mounted inside the wings. The engines were arranged in a “pusher” configuration with intake and cooling air entering through inlets in the wing leading edge. They drove three-bladed propellers with a diameter of 19 feet (5.8 meters) through a 0.381:1 gear reduction. The R-4360-25 was 9 feet, 1.75 inches (2.788 meters) long 4 feet, 4.50 inches (1.334 meters) in diameter, and weighed 3,483 pounds (1,580 kilograms).

The airplane’s maximum speed was 346 miles per hour (557 kilometers per hour) and cruising speed was 216 miles per hour (348 kilometers per hour). It had an estimated range of 9,500 miles (15,290 kilometers) with a 10,000 pound (4,536 kilogram) bomb load.

The prototype Convair XB-36, 42-13570, lifts off the runway at Fort Worth, Texas. (U.S. Air Force)
The prototype Consolidated-Vultee XB-36, 42-13570, lifts off the runway at Fort Worth, Texas. (U.S. Air Force)

After testing, improvements were incorporated into the second prototype, YB-36 42-13571. In June 1948, the XB-36 was modified with R-4360-41 engines, and the main landing gear was changed from a single-wheel design to a 4-wheel bogie. With these and other changes the XB-36 was redesignated YB-36A. It was used for continued testing for the next several years, but was eventually stripped of its engines and equipment and used for firefighter training at the adjacent Carswell Air Force Base.

The YB-36 was selected for production as the B-36A Peacemaker. The B-36 series was produced in both bomber and reconnaissance versions and was in front line service from 1949 to 1959. Beginning with the B-36D, four turbojet engines were mounted beneath the wings in pods similar to those on the Boeing B-47 Stratojet, greatly increasing the bomber’s performance. A total of 384 were built. Only five still exist. The Peacemaker was never used in combat.

The Convair XB-36 in flight. (U.S. Air Force)
The Consolidated-Vultee XB-36, 42-13570, in flight. (U.S. Air Force)

© 2018, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather

7 August 1963

The first Lockheed YF-12A interceptor, 60-6934, flown by James D. Eastham, lands at Groom Lake, Nevada, after its first flight, 7 August 1963. (U.S. Air Force)
James D. Eastham
James D. Eastham (1918–2016)

7 August 1963: The first Lockheed YF-12A interceptor, 60-6934, took off from a top secret air base at Groom Lake, Nevada, on its first flight. Lockheed test pilot James D. Eastham was at the controls.

Three YF-12A prototypes s were built. They were Mach 3+ interceptors developed from the Central Intelligence Agency “Oxcart” Lockheed A-12 reconnaissance airplane.

The interceptors were equipped with a very effective Hughes fire control system and armed with three Hughes AIM-47 Falcon air-to-air missiles. In 1965 the U.S. Air Force placed an order for 93 F-12B interceptors for the Air Defense Command, but Secretary of Defense Robert McNamara continually refused to release the funds which Congress had appropriated. Eventually the contract was cancelled.

In testing, a YF-12A launched a Falcon missile while flying at Mach 3.2 at 74,000 feet (22,555 meters). It successfully intercepted and destroyed a target drone flying at only 500 feet (152 meters).

Lockheed YF-12A 60-6934 at Groom Lake, Nevada. (Central Intelligence Agency)
Lockheed YF-12A 60-6934 at Groom Lake, Nevada. (Central Intelligence Agency)

On 1 May 1965, YF-12A 60-6936, flown by Colonel Robert L. Stephens and Lieutenant Colonel David Andre, set a world speed record of 2,070.101 miles per hour (3,331.505 kilometers per hour) and a sustained altitude record of 80,257.86 feet (22,677 meters).

Lockheed YF-12A 60-6934 in flight. (U.S. Air Force)
Lockheed YF-12A 60-6934 in flight. (U.S. Air Force)

60-6934 was damaged beyond repair in a runway accident at Edwards Air Force Base, 14 August 1966. Part of the airplane was salvaged and used to construct the only SR-71C, 64-17981, a two-seat trainer. The third YF-12A, 60-6936, was destroyed when the crew ejected during an inflight fire near Edwards AFB, 24 June 1971. The only remaining YF-12A, 60-6935, is in the collection of the National Museum of the United States Air Force, Wright-Patterson AFB, Ohio.

Lockheed YF-12A 60-6934. (U.S. Air Force)
Lockheed YF-12A 60-6934. (U.S. Air Force)
Clarence L. (“Kelly”) Johnson, Director of Lockheed’s Advanced Development Projects (“the Skunk Works”) with the first YF-12A interceptor, 60-6934. (Lockheed Martin)

© 2017, Bryan R. Swopes

Facebooktwittergoogle_plusredditpinterestlinkedinmailby feather