8 August 1929

Aviation, , , , , , , ,
Dr. Hugo Eckener (1868–1954)

8 August 1929: The rigid airship Graf Zeppelin, LZ 127, under the command of Dr. Hugo Eckener, departed Lakehurst Naval Air Station, New Jersey, heading east across the Atlantic Ocean on an around-the-world flight. The flight was sponsored by publisher William Randolph Hearst, who had placed several correspondents aboard.

Graf Zeppelin was named after Ferdinand Adolf Heinrich August Graf von Zeppelin, a German general and count, the founder of the Zeppelin Airship Company. The airship was constructed of a lightweight metal structure covered by a fabric envelope. It was 776 feet (236.6 meters) long. Contained inside were 12 hydrogen-filled buoyancy tanks, fuel tanks, work spaces and crew quarters.

A gondola mounted underneath contained the flight deck, a sitting and dining room and ten passenger cabins. The LZ-127 was manned by a 36 person crew and could carry 24 passengers.

LZ 127 was powered by five water-cooled, fuel injected 33.251 liter (2,029.1 cubic inches) Maybach VL-2 60° V-12 engines producing 570 horsepower at 1,600 r.p.m., each. Fuel was either gasoline or blau gas, a gaseous fuel similar to propane. The zeppelin’s maximum speed was 80 miles per hour (128 kilometers per hour).

The route of the flight was from Lakehurst NAS to the LZ 127 home base at Friedrichshafen. Germany. After refueling, it continued across Europe, Russia and Siberia, non-stop to Tokyo, Japan, where it moored and refueled at the Kasumigaura Naval Air Station. This leg crossed 7,297 miles (11,743 kilometers) in 101 hours, 49 minutes. After five days in Japan, Graf Zeppelin headed east across the Pacific Ocean to Mines Field, Los Angeles, California. This was the first ever non-stop flight across the Pacific Ocean. The distance was 5,986 miles (9,634 kilometers) and took 79 hours, 54 minutes. The transcontinental flight from Los Angeles back to the starting point at Lakehurst NAS, 2,996 miles (4,822 kilometers), took 51 hours, 13 minutes.

The total elapsed time for the circumnavigation was 21 days, 5 hours, 31 minutes. The route covered 20,651 miles (33,234 kilometers). The actual flight time was 12 days, 12 hours, 13 minutes, an average of 68.786 miles per hour (110.7 kilometers per hour).

Airship Graf Zeppelin, LZ 127. (Alexander Cohrs)

Graf Zeppelin made 590 flights and carried more than 13,000 passengers. It is estimated that it flew more than 1,000,000 miles. After the Hindenburg accident, it was decided to replace the hydrogen buoyancy gas with non-flammable helium. However, the United States government refused to allow the gas to be exported to Germany. With no other source for helium, in June 1938, Graf Zeppelin was deflated and placed in storage.

© 2020, Bryan R. Swopes

7 August 1971, 20:45:53 UTC, T plus 295:11:53.0

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Apollo 15 descends to the Pacific Ocean with two functional parachutes. (NASA)

7 August 1971: At 6:45 a.m., local time, 287 nautical miles (531 kilometers) north of Honolulu, Hawaii, the Apollo 15 command module Endeavour “splashed down” after twelve days in space. On board were Colonel David Randolph Scott, Mission Commander; Major Alfred Merrill Worden, Command Module Pilot; and Lieutenant Colonel James Benson Irwin, Lunar Module Pilot. All three were United States Air Force officers and NASA astronauts.

During the descent following reentry, one of the three main parachutes fouled. This did not cause any problems, though, as only two were necessary.

The spacecraft landed approximately 5.3 nautical miles (9.8 kilometers) from the primary recovery ship, the amphibious assault ship USS Okinawa (LPH-3).

The Apollo 15 flight crew disembarks the Sikorsky SH-3G recovery helicopter (Bu. No. 149930) aboard USS Okinawa (LPH-3), 21:25 UTC, 7 August 1971. Left to right, Scott, Worden, Irwin. (NASA)

Apollo 15 was the ninth manned mission of the Apollo Program, and the fourth to land on The Moon. The total duration of the flight was 12 days, 7 hours, 11 minutes, 53.0 seconds.

This was the first mission that the crew were not quarantined after returning to Earth.

The Apollo 15 command module is displayed at the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Ohio.

Apollo 15 command module (CSM-112) at the National Museum of the United States Air Force. (U.S. Air Force)

© 2017, Bryan R. Swopes

7 August 1963

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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 via Burbank Aviation Museum)

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

7 August 1951

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William Barton Bridgeman. (Boris Artzybasheff/TIME Magazine)

7 August 1951: Douglas Aircraft Company test pilot William Barton Bridgeman flew the rocket-powered U.S. Navy/NACA/Douglas D-558-2 Skyrocket, Bu. No. 37974 (NACA 144), to a record speed of Mach 1.88 (1,245 miles per hour/2,034 kilometers per hour) at Muroc Dry Lake (later Edwards Air Force Base) in the high desert of southern California.

The D-558-2 was airdropped at 34,000 feet (10,363 meters) from a Navy P2B-1S Superfortress, Bu. No. 84029 (a U.S. Air Force Boeing B-29-95-BW Superfortress, 45-21787, transferred to the Navy and heavily modified as a drop ship) flown by another Douglas test pilot, George Jansen.

Douglas D-558-II Skyrocket, Bu. No., 37974, NACA 144, is dropped from the Boeing P2B-1S Superfortress, Bu. No. 84029, NACA 137. (NASA)

In his autobiography, Bridgeman described the flight:

We are at 34,000 feet. My cue. Ten cold minutes preparing the ship for flight. The trap door springs and releases the captive Skyrocket swollen with explosive propellants. She blasts into flight.

Thirty seconds and I am supersonic. Sixty-eight thousand feet and this is it. Over the rim. Easy. The electrically controlled stabilizer flies her now. It takes over for me. At .6 G I push over just enough to get my speed. I am on the ragged edge between .6 G and .8 G. It is working! Everything is going according to my plan. It is so easy this time. Surely I cannot be breaking my last record without having to pay for it. The Machmeter is moving up, fluttering toward the Number 2. . . the rockets sputter and the fuel is gone. That’s all she wrote.

Late that afternoon the official speed attained by the Skyrocket reduced from data and film came out  of the aerodynamicists’ office. Mach 1.88.

—The Lonely Sky, William Bridgeman, Castle and Company LTD, London, 1956, Chapter XXII at Page 260.

NACA 144, a Douglas D-558-II Skyrocket, Bu. No. 37974, parked on Muroc Dry Lake. (NACA E-1441)

Bill Bridgeman had been a Naval Aviator during World War II, flying the Consolidated PBY Catalina and PB4Y (B-24) Liberator long range bombers with Bombing Squadron 109 (VB-109), “The Reluctant Raiders.” Bridgeman stayed in the Navy for two years after the end of the war, then he flew for Trans-Pacific Air Lines in the Hawaiian Islands and Southwest Airlines in San Francisco, before joining the Douglas Aircraft Company as a production test pilot. He flew new AD Skyraiders as they came off the assembly line at El Segundo, California. Bridgeman soon was asked to take over test flying the D-558-2 Skyrocket test program at Muroc Air Force Base.

Screen Shot 2016-08-07 at 11.13.14

The D-558-II Skyrocket was Phase II of a planned three phase experimental flight program. It was designed to investigate flight in the transonic and supersonic range. It was 46 feet, 9 inches (14.249 meters) long with a 25 foot (7.62 meter) wing span. The wings were swept back to a 35° angle. The Skyrocket was powered by a Westinghouse J34-WE-40 11-stage axial-flow turbojet engine, producing 3,000 pounds of thrust, and a Reaction Motors LR8-RM-6 four-chamber rocket engine, which produced 6,000 pounds of thrust. The rocket engine burned alcohol and liquid oxygen.

There were three D-558-2 Skyrockets. Between 4 February 1948 and 28 August 1956, they made a total of 313 flights. The Skyrocket flown by Bill Bridgeman to Mach 1.88 is in the collection of the Smithsonian Institution National Air and Space Museum.

NACA 144, a Douglas D-558-II Skyrocket, on display at the National Mall Building, Smithsonian Institution. (NASM)
NACA 144, a Douglas D-558-II Skyrocket, on display at the National Mall Building, Smithsonian Institution. (NASM)

© 2020, Bryan R. Swopes

7 August 1941

Aviation, , , , , , , , , ,
A prototype Grumman XTBF-1 torpedo bomber. (Ray Crupi Collection)

7 August 1941: Grumman Aircraft Engineering Corporation chief engineer and test pilot, Robert Leicester (“Bob”) Hall, took the XTBF-1, a prototype torpedo bomber, for its first flight. He quickly returned to the airfield. The airplane was seriously over-weight, its center of gravity was too far aft, and it was unstable in the yaw axis.

The first XTBF-1, U.S. Navy Bureau of Aeronautics serial number (“Bu. No.”) 00373, was modified to correct these faults. The engine mount was revised, moving the engine farther forward. A triangular fillet was added to the top of the fuselage in front of the vertical fin, and the weight was reduced.

Grumman XTBF-1 Bu.No. 00373. Note the dorsal fillet. (Northrop Grumman)

On 28 June 1942, 00373 caught fire during a test flight. Its crew safely bailed out but the prototype was destroyed.

The second prototype XTBF-1 was sent to the National Advisory Committee for Aeronautics Langley Memorial Aeronautical Laboratory at Hampton, Virginia, for testing in the 30- × 60-foot Full Scale Tunnel.

The second Grumman XTBF-1 prototype in the NACA Full Scale Tunnel. (NASA)

Before the airplane’s first flight, the U.S. Navy had ordered 286 production aircraft. In October 1941, the type was officially named “Avenger.” The first production airplane, Bu. No. 000393, made its first flight on 15 December 1941.

A flight crew boards a Grumman TBF-1 Avenger torpedo bomber, circa late 1941–early 1942. (Rudy Arnold Collection, Smithsonian Institution, National Air and Space Museum NASM-XRA-0780)

The Grumman Model 40, designated TBF-1 Avenger by the United States Navy, was a single engine torpedo bomber designed to operate from aircraft carriers. Initially it had a four-man crew: pilot, navigator, radio-operator/gunner and ball turret gunner. The TBF was 40 feet, 11½ inches (12.484 meters) long with a wingspan of 54 feet, 2 inches (16.510 meters) and height of 16 feet, 4¼ inches (4.991 meters).

Grumman TBF Avenger three-view illustration with dimensions. (U.S. Navy)

The XTBF-1 was powered by an air-cooled, supercharged, 2,603.943-cubic-inch-displacement (42.671 liters) Wright Cyclone 14 GR2600B698 (R-2600-8) two-row, fourteen-cylinder radial engine with a compression ratio of 6.9:1. The R-2600-8 was rated at 1,500 horsepower at 2,400 r.p.m., and 1,700 horsepower at 2,800 r.p.m. at Sea Level for Takeoff. The engine drove a 13 foot, 1 inch diameter ( meters), three-bladed Hamilton Standard constant speed propeller through a  0.5625:1 gear reduction unit. The R-2600-8 was 5 feet, 4.91 inches (1.649 meters) long, 4 feet, 6.26 inches (1.378 meters) in diameter, and weighed 1,995 pounds (904.9 kilograms).

A Grumman TBF-1 Avenger, mid-1942. (Hans Groenhoff Collection, Smithsonian Institution, National Air and Space Museum NASM-HGC-906)

© 2020, Bryan R. Swopes