Monthly Archives: March 2025

20 March 1966

Aviation, , , , , , ,
Test pilot Jack L. Zimmerman with the record-setting Hughes YOH-6A Light Observation Helicopter, 62-4213. (FAI)
Hughes Aircraft Division test pilot Jack L. Zimmerman with the record-setting Hughes YOH-6A Light Observation Helicopter, 62-4213. (FAI)

20 March 1966: At Edwards Air Force Base in the high desert of southern California, Hughes Aircraft Company test pilot Jack L. Zimmerman flew the third prototype YOH-6A Light Observation Helicopter, 62-4213, to set a Fédération Aéronautique Internationale (FAI) World Record for Distance Over a Closed Circuit Without Landing of 1,700.12 kilometers (1,056.41 miles).¹ Fifty-nine years later, this record still stands.

One week later, Zimmerman would set six more World Records ² with the “Loach.”

Hughes YOH-6A 62-4213 at Edwards Air Force Base, 1966. (FAI)
Hughes YOH-6A 62-4213 at Edwards Air Force Base, 1966. (FAI)

The Hughes Model 369 was built in response to a U.S. Army requirement for a Light Observation Helicopter (“L.O.H.”). It was designated YOH-6A, and the first aircraft received U.S. Army serial number 62-4211. It competed with prototypes from Bell Helicopter Company (YOH-4) and Fairchild-Hiller (YOH-5). All three aircraft were powered by a lightweight Allison Engine Company turboshaft engine. The YOH-6A won the three-way competition and was ordered into production as the OH-6A Cayuse. It was nicknamed “loach,” an acronym for L.O.H.

The YOH-6A was a two-place light helicopter, flown by a single pilot. It had a four-bladed, articulated main rotor which turned counter-clockwise, as seen from above. (The advancing blade is on the helicopter’s right.) Stacks of thin stainless steel “straps” fastened the rotor blades to the hub and were flexible enough to allow for flapping and feathering. Hydraulic dampers controlled lead-lag. Originally, there were blade cuffs around the main rotor blade roots in an attempt to reduce aerodynamic drag, but these were soon discarded. A two-bladed semi-rigid tail rotor was mounted on the left side of the tail boom. Seen from the left, the tail-rotor rotates counter-clockwise. (The advancing blade is on top.)

The third prototype YOH-6A, 62-4213, testing the XM-7 minigun. (U.S. Army)
The third prototype YOH-6A, 62-4213, testing the XM-7 twin M60 7.62 mm weapons system. (U.S. Army)

The YOH-6A was powered by a T63-A-5 turboshaft engine (Allison Model 250-C10) mounted behind the cabin at a 45° angle. The engine was rated at 212 shaft horsepower at 52,142 r.p.m. (102% N1) and 693 °C. turbine outlet temperature for maximum continuous power, and 250 shaft horsepower at 738 °C., 5-minute limit, for takeoff. Production OH-6A helicopters used the slightly more powerful T63-A-5A (250-C10A) engine.

The Hughes Tool Company Aircraft Division built 1,420 OH-6A Cayuse helicopters for the U.S. Army. The helicopter remains in production as AH-6C and MH-6 military helicopters, and the MD500E and MD530F civil aircraft.

Hughes YOH-6A 62-4213 is in the collection of the United States Army Aviation Museum, Fort Rucker, Alabama.

U.S. Army Hughes YOH-6A prototype 62-4213 at Le Bourget, circa 1965.
U.S. Army Hughes YOH-6A prototype 62-4213 at Aéroport de Paris – Le Bourget, 19 June 1965. (R.A. Scholefield via AVIAFORA)
Jack Zimmerman (The Maroon 1940)

Jack Louis Zimmerman was born 1 September 1921 at Chicago, Illinois, the second of three children of Bernard Zimmerman, an electrician, and Esther Rujawski Zimmerman. Jack graduated from Hirsch High School in Chicago in 1940. He then studied engineering at the University of Chicago, but left to enlist in the U.S. Army Air Corps. He graduated from flight school in 1943 and was commissioned a second lieutenant.

Lieutenant Zimmerman was sent to Freeman Field, Indiana, as part of the Army’s first class of student helicopter pilots, training on the Sikorsky R-4. On completion of training he was assigned to a Liberty ship in the western Pacific as part of a Project Ivory Soap Aviation Repair Unit.

Taking off from the Army Transport Service ship USAT Maj. Gen. Robert Olds (formerly, the Liberty ship, SS Daniel E. Garrett), Lieutenant Zimmerman’s helicopter crashed into the sea. For his heroic actions in saving a passenger’s life, he was awarded the Soldier’s Medal:

“For heroism displayed in rescuing an enlisted man from drowning on 1 November 1944. While taking off from the flight deck of the SS Daniel E. Garrett, Lieutenant Zimmerman with Private William K. Troche as passenger was forced to land at sea. Lieutenant Zimmerman at the risk of his life made several dives into the plane when his passenger had difficulty in extricating himself from the craft. When Private Troche’s life preserver failed to operate properly, Lieutenant Zimmerman supported him in the water for approximately 30 minutes and afterwards pulled him to a life preserver, which had been thrown from the ship. The heroism displayed by Lieutenant Zimmerman on this occasion reflects great credit upon himself and the military service.” —http://collectair.org/zimmerman.html

Following World War II, Jack Zimmerman was employed as a commercial pilot, and then a test pilot for the Seibel Helicopter S-4 and YH-24 light helicopters, and when the company was bought by Cessna, he continued testing the improved Cessna CH-1 and UH-41 Seneca. In 1963, Zimmerman began working as a test pilot for the Hughes Tool Company’s Aircraft Division. He retired in 1982.

Jack Louis Zimmerman died at San Diego, California, on his 81st birthday, 1 September 2002.

¹ FAI Record File Number 762

² FAI Record File Numbers 771, 772, 9920, 9921, 9922, and 9923

© 2019, Bryan R. Swopes

20 March 1945

Aviation, , , , , , , , , , , , ,
Tony LeVier and the first prototype Lockheed XP-80A, 44-83021, in flight over southern California’s high desert, 1945. (Lockheed Martin)
Anthony W. (“Tony”) LeVier

20 March 1945: Tony LeVier was conducting a test flight of the first prototype Lockheed XP-80A, 44-83021, near Muroc Army Air Field (now known as Edwards Air Force Base).

The XP-80A was developed from the original XP-80 prototype, but was larger to incorporate a more powerful General Electric I-40 turbojet engine in place of the original Allis-Chalmers J36 (a license-built version of the British Halford H.1B).

The I-40 was a single-shaft turbojet which used a double-inlet, single-stage, centrifugal-flow compressor, fourteen straight-through combustors and a single-stage axial-flow turbine. The engine had a maximum speed of 11,500 r.p.m. and produced 4,000 pounds of thrust (17.79 kilonewtons). The I-40 was 48 inches (1.22 meters) in diameter and weighed 1,820 pounds (826 kilograms). The I-40 would be produced by Allison Division of General Motors as the J33 series.

General Electric I-40 turbojet engine cross section. (NASA)

At 15,000 feet (4,572 meters), LeVier put the XP-80A into a dive, intending to level off at 10,000 feet (3,048 meters) for a high-speed run. However, at 11,000 feet (3,353 meters), the single-stage turbine inside the jet engine failed and fragments tore through the prototype’s fuselage. The tail section of the airplane was cut off and the XP-80A went out of control.

An example of a turbine failure in a Lockheed P-80. (San Diego Air and Space Museum)

The XP-80A was not equipped with an ejection seat and LeVier had difficulty getting out, but finally escaped at about 4,000 feet (1,219 meters).

44-83021 crashed near the town of Rosamond and was completely destroyed. Tony LeVier’s parachute was swinging and he was severely injured when he hit the ground. His injuries kept him from flying for the next six months.

Lockheed XP-80A 44-83021 (U.S. Air Force)
Lockheed XP-80A 44-83021 (U.S. Air Force)

The Lockheed XP-80A was a single-place, single engine prototype fighter. It was 34 feet, 6 inches (10.516 meters) long with a wingspan of 39 feet, 0 inches (11.887 meters) and overall height of 11 feet, 4 inches (3.454 meters). It had an empty weight of 7,225 pounds (3,277 kilograms) and gross weight of 9,600 pounds (4,354 kilograms).

Armament consisted of six Browning .50-caliber AN-M2 machine guns with 300 rounds of ammunition per gun.

Two XP-80As were built. These were followed by twelve YP-80A Shooting Star service test aircraft. The Lockheed P-80A Shooting Star was ordered into production with an initial contract for 500 aircraft. This was soon followed by a second order for 2,500 fighters.

Wreckage of XP-80A 44-83021 loaded on a flat bed trailer. (U.S. Air Force)
Wreckage of XP-80A 44-83021 loaded on a flat bed trailer. (U.S. Air Force)

© 2019, Bryan R. Swopes

20 March 1937

Aviation, , , , , , , ,
Amelia Earhart's damaged Lockheed Electra 10E, at Luke Field, Ford Island, 20 March 1937. Earhart is standing in the open cockpit hatch. (AP/Wichita Eagle)
Amelia Earhart’s damaged Lockheed Electra 10E, at Luke Field, Ford Island, 20 March 1937. Earhart is standing in the open cockpit hatch. (AP/Wichita Eagle)

20 March 1937: After completing repairs and preparation for the second leg of her around-the-world flight—Hawaii to Howland Island—Amelia Earhart’s Lockheed Electra 10E, NR16020, was moved from Wheeler Field to Luke Field on Ford Island on 19 March to take advantage of the longer, fully paved runway.

Paul Mantz had warmed the engines at 5:00 a.m., 20 March, then shut them down. He would not be aboard for this flight. Amelia Earhart, Captain Manning and Captain Noonan boarded the Electra at 5:30 a.m. and Earhart restarted the engines. At 5:40 a.m., she began to taxi to the northeast corner of the runway. Weather was good, with a ceiling of 3,000 feet, visibility 3,500 feet in pre-dawn darkness, and wind from the south at 2 miles per hour.

At 5:53 a.m., Amelia Earhart accelerated for takeoff. A United States Army Board of Investigation report describes what happened next:

THE CRASH:

On reaching the end Miss Earhart turned and after a brief delay opened both throttles. As the airplane gathered speed it swung slightly to the right. Miss Earhart corrected this tendency by throttling the left hand motor. The airplane then began to swing to the left with increasing speed, characteristic of a ground loop. It tilted outward, right wing low and for 50 or 60 feet was supported by the right wheel only. The right-hand landing-gear suddenly collapsed under this excessive load followed by the left. The airplane spun sharply to the left on its belly amid a shower of sparks from the mat and came to rest headed about 200 degrees from its initial course. There was no fire. Miss Earhart and her crew emerged unhurt. The visible damage to the airplane was as follows:- Right wing and engine nacelle severely damaged, left engine nacelle damaged on under side, right hand rudder and end of stabilizer bent. The engines were undamaged. The oil tanks were ruptured. . . .

FINDINGS:  . . . after a run of 1200 feet the airplane crashed on the landing mat due to collapse of the landing gear as a result of an uncontrolled ground loop; the lack of factual evidence makes it impossible to establish the reason for the ground loop; that as a result of the crash the airplane was damaged to an extent requiring major overhaul. . . .

—excerpts from PROCEEDINGS OF A BOARD OF OFFICERS CONVENED TO INVESTIGATE THE CRASH OF MISS AMELIA EARHART AT LUKE FIELD, 20 MARCH 1937

The Electra was extensively damaged. There were no injuries, but the Electra was sent back to Lockheed at Burbank, California, aboard the passenger liner, SS Lurline, for repair.

At the time of the accident, NR16020 had flown 181 hours, 17 minutes, total time since new (TTSN). 

Paul Mantz, who was not aboard during the crash, stands in the Electra's cockpit. Amelia Earhart and Fred Noonan are standing on the wing, 20 March 1937.
Paul Mantz, who was not aboard during the crash, stands in the Electra’s cockpit. Amelia Earhart and Fred Noonan are standing on the wing, 20 March 1937. (AP/Wichita Eagle)

© 2017, Bryan R. Swopes

20 March 1935

Aviation, , , , , , , , , , ,
The second prototype Grumman XF3F-1, Bu. No. 9727, photographed 10 January 1936. (U.S. Navy, Naval History and Heritage Command, NH 44277)

20 March 1935: At Farmingdale, New York, test pilot James H. (“Jimmy”) Collins took the Grumman Aircraft Engineering Corporation’s prototype XF3F-1, Bu. No. 9727, for its first flight. Collins made three flights that day.

[According to serial number authority, Joe Baugher, three XF3F-1 prototypes had the same manufacturer’s serial number, 257, and the same U.S. Navy Bureau of Aeronautics serial number, 9727. Two of them were destroyed during flight testing.]

Grumman XF3F-1 Bu. No. 9727, with landing gear extended. (San Diego Air & Space Museum Archives, Catalog #: 17_000148)

The XF3F-1 was a prototype fighter built for the United States Navy. It was a single-place, single-bay, wire-braced biplane with retractable landing gear. The airplane was of all metal construction. It was a development of the F2F, then in production.

Grumman XF3F-1 Bu. No. 9727. (Grumman Aircraft Engineering Corporation 2815)

Collins  had performed nine dive tests of the XF3F-1. He began the tenth and final test at 6:05 p.m., 22 May 1935. After climbing to 20,000 feet (6,096 meters), he put the biplane into a full power, vertical dive. At a speed of 400 miles per hour (644 kilometers per hour), he pulled out of the dive at 8,000 feet (2,438 meters) but the airplane’s propeller and wings were torn off. An accelerometer indicated that the airplane had sustained a force of 14 gs. The airplane crashed into the Pinelawn Cemetery.

Witnesses at the scene (which included Collins’ sister, Mrs. Elizabeth Collins Joyhard) said that Collins was still alive when he was pulled from the wreckage. He is reported to have said, “Pull me out boys. I’m all through. Never mind wiping my face, I’m done.” ¹

For these tests, he was to have been paid $1,500. On his last day, he had told friends that he planned to stop flying and pursue a career as an aviation writer.

Grumman XF3F-1 Bu. No. 9727 (San Diego Air & Space Museum Archives, Catalog #: 16_003712)

The XF3F-1 used the same engine as the production F2F-1: An air-cooled, supercharged 1,534.94 cubic inch (25.15 liter) Pratt & Whitney S1A2 Twin Wasp Jr. (R-1535-72) two-row, 14-cylinder radial. This was a direct drive engine with a compression ratio of 6.75:1 requiring 87-octane gasoline. The supercharger impeller ratio was 12:1. The R-1535-72 was rated at 650 horsepower (485 kilowatts) at 2,200 r.p.m. at 7,500 feet (2,286 meters), and 700 horsepower (522 kilowatts) at 2,250 r.p.m. for takeoff.

Grumman F3F-1, Bu. No. 0211, s/n 274. This airplane crashed at sea near NAS Miami, March 1942. (San Diego Air & Space Museum, Roger Bilstein Collection 00032)

The production F3F-2 was 23 feet, 2 inches (7.061 meters) long with a wingspan of 32 feet (9.754 meters) and height of 9 feet, 4 inches (2.845 meters). The total wing area was 260 square feet (25.16 square meters). It had an empty weight of 3,285 pounds ( 1,490 kilograms), and maximum takeoff weight of 4,795 pounds (2,175 kilograms). Unlike the XF3F-1, the F3F-2 was powered by a Wright R-1820-22 rated at 950 horsepower. It had a maximum speed of 264 miles per hour (425 kilometers per hour) at 15,000 feet (4,572 meters), Its maximum rate of climb was 2,750 feet per minuted (14 meters per second), and the service ceiling was 33,200 feet (10,119 meters). It had a range of 980 miles (1,577 kilometers). The F3F-2 was armed by a .30-caliber Browning M1919 machine gun with 500 rounds of ammunition, and a .50-caliber Browning M2 machine gun with 200 rounds.

In August 1935 the U.S. Navy contracted for 54 F3F-1s. The first one was delivered 29 January 1936. A total of 147 F3Fs were built between 1935 and 1938. The F3F was the U.S. Navy’s last biplane fighter. The type was retired in 1943.

James H. Collins was born 25 April 1904, the second child of John Collins, an Irish immigrant to the United States, and Ella E. Ray Collins. His father died when Jimmy was four years old, and his mother, when he was 11. He then lived with an aunt and uncle.

Collins attended Central High School, Akron, Ohio, and worked nights at the B.F. Goodrich rubber factory. After graduating, he enrolled at the University of Akron. He was a member of the Lambda Delta Chi (ΛΔΧ) fraternity.

In 1924, Collins entered the U.S. Army Air Service Primary Flying School at Brooks Field, San Antonio, Texas, and then went on to the Advanced Flying School at Kelly Field, also in San Antonio. He was in the same class as Charles A. Lindbergh. After graduating, he was commissioned a second lieutenant in the New York National Guard, and assigned to the 102nd Observation Squadron, 27th Division Air Service, at Miller Field, Staten Island, New York.

During the Great Depression, Collins’ service with the New York National Guard did not provide full time employment. He had to work at other jobs, which included returning to B.F. Goodrich. In 1925, he  briefly returned to the University of Akron, then volunteered for six months active duty with the 94th Pursuit Squadron at Selfridge Field, Harrison, Michigan. He served as assistant engineering and operations officer. He was then commissioned as a lieutenant in the regular Air Service, United States Army. He was assigned as an instructor at March Field, near Riverside, California and back at Brooks Field.

Unable to complete a formal university degree, Collins decided to gain the equivalent of a liberal arts degree through self study. It was around this time that he became a communist. He considered emigrating to the Union of Soviet Socialist Republics.

In 1927, Lieutenant Collins resigned his commission. He then worked as an inspector for the Department of Commerce, the federal agency overseeing civil aviation in the United States. That was followed by employment as chief test pilot for the Curtiss Aeroplane and Motor Company, Hammondsport, New York.

Test Pilot, by Jimmy Collins, © 1935, by his wife.

In 1932, Jimmy Collins married Miss Dolores Lacy. They would have two children, Darr, named after a friend of Jimmy’s, and Susan Ann Collins. With the depression ongoing, Collins often lived away from his family, having sent them to live with his older sister in Oklahoma. By doing dive tests, he had hoped to earn enough money to bring them back to New York.

James H. Collins’ remains were cremated at the Fairfield Mortuary, Garden City, New York, then spread from an airplane over the Atlantic Ocean off Jones Beach at 6:05 p.m., 29 March 1935.

Jimmy Collins was the author of Test Pilot, published after his death by The Sun Dial Press, Garden City, New York.

¹ Daily News, Vol. 16, No. 232, Saturday, 23 March 1935, Page 6, Column 1

© 2023, Bryan R. Swopes

20 March 1932

Aviation, , , , , ,
The first of three Boeing Model 248 prototypes, XP-26 32-412. (Boeing)

20 March 1932: Boeing chief test pilot Leslie Ralph Tower takes the Model 248 (designated XP-936, and later, XP-26), Air Corps serial number 32-412, for its first flight.

The Boeing P-26 was a single-seat, single-engine monoplane. It was the first all-metal U.S. Army pursuit, but retained an open cockpit, fixed landing gear and its wings were braced with wire. The airplane was 23 feet, 7 inches (7.188 meters) long with a wingspan of 28 feet (8.534 meters). The empty weight of the prototype was 2,119 pounds (961.2 kilograms) and gross weight was 2,789 pounds (1,265.1 kilograms).

Boeing XP-936 No. 3 in flight. This airplane would be designated P-26, serial number 32-414. It is the airplane flown by Lieutenant Robert Kinnaird Giovannoli, 8 March 1936. (Boeing)

The Y1P-26 was powered by an air-cooled, supercharged, 1,343.804-cubic-inch-displacement (22.021 liter) Pratt & Whitney R-1340-21 (Wasp S2E), a single-row, nine-cylinder radial engine. The P-26A and P-26C were powered the Pratt & Whitney R-1340-27 (Wasp SE), while the P-26B used a more powerful, fuel-injected R-1340-33 (Wasp D2). Each of these engines were direct drive and had a compression ratio of 6:1. The engine was surrounded by a Townend Ring which reduced aerodynamic drag and improved engine cooling.

The R-1340-21 had a Normal Power rating of 600 horsepower at 2,200 r.p.m. at 6,000 feet (1,829 meters); 500 horsepower at 2,200 r.p.m. at 11,000 feet (3,353 meters); and 500 horsepower at 2,000 r.p.m. for takeoff. It required 87-octane gasoline. The –21 had a diameter of 3 feet, 3.44 inches (1.307 meters) and weighed 715 pounds (324 kilograms).

The R-1340-27 had a Normal Power and Takeoff power rating of 570 horsepower at 2,200 r.p.m., to 7,500 feet (1,524 meters), using 92-octane gasoline. The –27 was 3 feet, 7.25 inches (1.099 meters) long, 4 feet, 3.50 inches (1.308 meters) in diameter and also weighed 715 pounds (324 kilograms).

The R-1340-33 was rated at 575 horsepower at 2,200 r.p.m. to 10,000 feet (3,048 meters), and 600 horsepower at 2,120 r.p.m. for Takeoff, with 87-octane gasoline. It was 3 feet, 10.75 inches (1.187 meters) long, with the same diameter as the –27. It weighed 792 pounds (359 kilograms).

The engines drove a two-bladed, Hamilton Standard adjustable-pitch propeller.

19th Pursuit Squadron commanding officer’s Boeing P-26 in flight over Oahu, Territory of Hawaii, 6 March 1939. (NASM)

The pursuit had a maximum speed of 227 miles per hour (365 kilometers per hour) at 10,000 feet (3,048 meters), and a service ceiling of 28,900 feet (8,809 meters).

As a pursuit, the P-26 was armed with two air-cooled Browning M1919 .30-caliber machine guns, synchronized to fire forward through the propeller arc.

Boeing built 136 production P-26s for the Air Corp and another 12 for export. Nine P-26s remained in service with the Air Corps at the beginning of World War II.

A Boeing P-26, A.C. 33-56, in the Full-Scale Wind Tunnel at the National Advisory Committee for Aeronautics Langley Memorial Aeronautical Laboratory, 1934. This “Peashooter,” while assigned to the 6th pursuit Squadron, ditched north of Kaluku, Oahu, Hawaii, 14 December 1938. (NASA)
Leslie Ralph Tower

Leslie Ralph Tower was born at Sisseton, South Dakota, 21 January 1903. He was the first of three children of Ralph R. Tower, a farmer who would later serve as a state senator for Montana, and Mayme Amanda Johnson Tower, a Swedish immigrant.

Les Tower attended high school at Polson, Montana, graduating in 1922. He then attended the University of Washington, where he studied engineering. He was a member of the Radio Club.

Tower enlisted in the United States Army as an aviation cadet, training at Brooks and Kelly airfields in Texas. He then served with the 2nd Bombardment Squadron at Langley Field, Virginia.

In 1925 Tower started working for Boeing as a draftsman, but soon began test flying new airplanes, which included the B-9 bomber and the Model 247 commercial airliner. He also demonstrated and delivered Boeing airplanes around the world.

On 20 August 1935, Tower and Louis Wait flew the Model 299 from Seattle to Dayton, approximately 2,100 miles, in 9 hours, 3 minutes, averaging 233 miles per hour (375 kilometers per hour).

Les Tower was aboard the XB-17 as an observer during the 30 October flight. He saw that the control locks had not been released and tried to reach them, but was unable. In the fire that followed the crash, Tower suffered severe burns to his face, right arm and both legs.¹

The wreck of the Boeing Model 299, NX13372, burns after the fatal crash at Wright Field, 30 October 1935. (U.S. Air Force)

Leslie Ralph Tower died of his injuries 19 November 1935 at Miami Valley Hospital in Dayton. His remains were transported by train, escorted by Army airplanes, and were buried at Lakeview Cemetery, Polson, Montana.

¹ Leslie Tower was pulled from the burning wreckage of the XB-17 by Lieutenant Robert Kinnaird Giovannoli, who was awarded the Soldier’s Medal for his actions. Lieutenant Giovannoli was killed 8 March 1936 when he right wing of his Boeing P-26 pursuit, serial number 32-414, came off in flight over Logan Field, near Baltimore, Maryland. That airplane appears in the second photograph, above.

© 2025, Bryan R. Swopes