Graf Zeppelin over the airship hangars at Friedrichshafen. (The Lothians collection)
18 September 1928: The rigid airship, Graf Zeppelin, LZ 127, made its first flight at Friedrichshafen, Germany.
Graf Zeppelin was named after Ferdinand Adolf Heinrich August Graf von Zeppelin, a German general and count, the founder of Luftschiffbau Zeppelin GmbH (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.
A dining room aboard Graf Zeppelin.
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).
During the next nine years, Graf Zeppelin made 590 flights, including an around the world flight, 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.
In his excellent history of the Royal Air Force leading up to the Battle of Britain, Duel of Eagles, Group Captain Peter Wooldridge Townsend, CVO, DSO, DFC and Bar, describes how Germany used Graf Zeppelin for reconnaissance missions, occasionally overflying the British Isles in poor weather due to “navigational errors.” The airship was scouting for radar sites and RAF radio frequencies. (This airship may have been Graf Zeppelin II, LZ 130.)
Both airships were scrapped and their duralumin structures salvaged.
Roland Rohlfs after setting an FAI altitude record of 9,241 meters (30,318 feet) at Garden City, New York, 20 July 1919. The airplane is the Curtiss 18T-2 Wasp, Bu. No. A3325. (San Diego Air and Space Museum Archives)
18 September 1919: Curtiss Engineering Corporation test pilot Roland Rohlfs set a Fédération Aéronautique Internationale (FAI) World Record for Altitude when he flew a Curtiss 18T-2 Wasp triplane, U.S. Navy Bureau of Aeronautics serial number A3325, to an altitude of 9,577 meters (31,421 feet) over Roosevelt Field, Long Island, New York.¹ Contemporary sources, however, reported that Rohlfs’ peak altitude was 34,610 feet (10,549 meters).
This record broke Rohlfs’ previous FAI World Record for Altitude of 9,241 meters (30,318 feet) set at Garden City, New York, 30 July 1918.²
Aero Club of America officials check altitude-recording barographs with Roland Rohlfs after a record-setting flight. (San Diego Air and Space Museum Archives)
Rohlfs took off at 12:06 p.m. and reached his peak altitude 1 hour, 15 minutes later. The air temperature was -43 °F. (-41.7 °C.). He touched down after 1 hour, 53 minutes.
The Curtiss 18T Wasp was a two-place single-engine triplane fighter designed and built for the United States Navy at the end of World War I. A3325 had been loaned to the U.S. Army to set an airspeed record of 163 miles per hour (262 kilometers per hour), before being returned to Curtiss for additional testing. It was fitted with a set of longer wings and redesignated 18T-2. The second 18T, A3326, retained the standard 32’–½” (9.766 meters) wings and was redesignated 18T-1.
The Curtiss 18T-2 was 23 feet (7.010 meters) long with a wingspan of 40 feet, 7½ inches (12.383 meters). It weighed 1,900 pounds (862 kilograms). The airplane was powered by a water-cooled, normally-aspirated, 1,145.11-cubic-inch-displacement (18.765 liter) Curtiss-Kirkham K-12 60° single-overhead-cam V-12 engine which produced 375 horsepower at 2,250 r.p.m., and 400 horsepower at 2,500 r.p.m. The K-12 drove a two-bladed fixed-pitch propeller through a 0.6:1 gear reduction.
Roland Rohlfs and the Curtiss 18T-2 take off from Roosevelt Field, Long Island, New York, at 12:06 p.m., 18 September 1919. (San Diego Air and Space Museum Archives)
A3325 later crashed during a test flight. Its sistership, A3326, suffered a crankshaft failure and was destroyed. The Curtiss 18T was never placed in series production.
Captain Rudolph William Schroeder with the Bristol fighter which he flew to a world record altitude, 18 September 1918. Note the gap between to bottom of the fuselage and the lower wing. (U.S. Air Force)
18 September 1918: Captain Rudolph William Schroeder, United States Army Air Service, the Chief Test Pilot of the Engineering Division at McCook Field, Fairfield, Ohio, flew a Bristol F.2B fighter to set two Fédération Aéronautique Internationale (FAI) World Records.¹ ²
Aerial Age Weekly reported:
CAPTAIN SCHROEDER ESTABLISHES WORLD ALTITUDE RECORD
THE Contest Committee of the Aero Club of America has homologated the world’s altitude record made by Captain R. W. Schroeder, in a Bristol fighter equipped with a 300 H. P. Hispano-Suiza motor, of 28,900 feet above sea level, during a flight on September 18, 1918, at Wilbur Wright Field, Fairfield, Ohio, near Dayton.
Nothing was more fitting. While the Allies’ aviators overseas are beating the Germans on the various fronts, an American aviator, Captain R. W. Schroeder, U.S. Air Service, beats the German aeroplane altitude record.
Captain Schroeder left the ground at 1:45 P. M., September 18, 1918. and reached his highest point if 105 minutes, which would have been at about 3:30 P. M. It took him about twenty minutes to descend, landing about 200 miles from where he started, at about 3:50 P. M.
Captain Schroeder i sin charge of all Performance Tests at the Wilbur Wright Station and his duties require him to go to 21,000 and 22,000 feet quite often, and he generally goes without oxygen. In this record climb, he got well up to 25,000 feet without oxygen. He used no anti-freezing mixture and his maximum water temperature was 85 degrees centigrade at the start minimum and of 60 degrees centigrade at the highest altitude. The temperature of the air was 32 degrees centigrade below zero.
The reports, including the two barograph charts, duly calibrated and corrected: the performance curves, and the temperature record were certified to by Lieut. George B. Patterson, O. I. C. Performance Test Reports and the instruments were calibrated by the Bureau of Standards, and adjusted locally at the McCook Field Laboratory and personally installed on the aeroplane by Lieut. Patterson.
The previous American altitude record was made by Caleb Bragg at Mineola, L. I., September 20, 1917, in a Wright Martin, Model V machine, when he reached an altitude of 20,250 feet, and the last world’s record of the International Aeronautic Federation made by G. Legagneux in France on the 28th of December, 1913, was 6,120 meters (20,258 feet). In July, 1914, a German aviator was reported as having flown to 26,200 feet, but the record was never submitted for homologation.
This world’s record, made by Captain Ruddy W. Schroeder, is the first world’s aeroplane altitude record held by an American since the world’s altitude record made by Lincoln Beachey, at Chicago, Ill., during the International Meet, August 20, 1911, when he reached the height of 11,642 feet (3,548 meters).
Under the rules of the International Aeronautic Federation, the international aeronautic body which controls all aeronautic sports and gives the necessary official records, a pilot must hold the International Aviator’s certificate to have his record recognized. This certificate is issued in the United State by the Aero Club of America, which is the federation’s sole representative in this country. Captain Schroeder held the the F. A. I. certificate at the time he made the record, therefore his record will be accepted by all the countries affiliated with the International Aeronautic Federation and the Pan-American Aeronautic Federation, which represents twenty Latin American republics.
Under the rules of the Federation to establish an altitude record it is necessary to best the old record by at lease 100 meters. Captain Schroeder, therefore, beat the record by a good margin and has gone higher the the highest mountain, with the exception of the highest peak in the Himalaya, which rises 29,002 feet.
Captain Schroder is a veteran of the aeronautic movement. He is an old time member of the Aero Club of Illinois and well known for his ability as an aviator and aeronautic engineer.
—AERIAL AGE WEEKLY, Vol. VIII, No. 5, 14 October 1918
Bristol F.2B C823. (BAE Systems)
The Bristol F.2B was a two-place single-engine two-bay biplane fighter, designed by Captain Frank Sowter Barnwell, O.B.E., A.F.C., and built by the British and Colonial Aeroplane Co., Ltd., Filton and Brislington, Bristol, England, and several other manufacturers. More than 3,800 were produced and some considered it to be the best two-place fighter of the First World War.
The F.2B was 25 feet, 9 inches (7.849 meters) long. Both upper and lower wings had a span of 39 feet, 3 inches (11.979 meters) and a chord of 5 feet, 6 inches (1.676 meters). The total wing area was 405 square feet (37.63 square meters). Both wings had an angle of incidence of 1½°, and 3½° dihedral. There was no sweep. The lower wing was staggered 1 foot, 5 inches (0.432 meters) behind the upper wing. In order to give the gunner a better range of fire, the lower wing was not attached to the bottom of the fuselage. This had the effect of lowering the upper wing while maintaining a vertical gap of 5 foot, 5 inches (1.651 meters).
The gross weight of the F.2B was approximately 2,810 pounds (1,275 kilograms).
Bristol F.2A
The Bristol Fighters were powered by Rolls-Royce Falcon engines. The F.2B was equipped with the Falcon III. The Falcon was a water-cooled, normally-aspirated 867.080-cubic-inch-displacement (14.209 liters) single-overhead camshaft 60° V-12 engine. The Falcon III had a compression ratio of 5.3:1 and had a Sea Level rating of 288 horsepower at 2,300 r.p.m. The propeller gear reduction ratio was 0.589:1.
The F.2B had a maximum speed of 125 miles per hour (201 kilometers per hour) at Sea Level, and 113 miles per hour (182 kilometers per hour) at 10,000 feet (3,048 meters). The fighter could climb to 10,000 feet in 11.5 minutes, and to 15,000 feet (4,572 meters) in 21.5 minutes.
The United States was interested in producing its on version of the F.2B, to be powered by the American Liberty V-12 engine instead of the Rolls-Royce Falcon III V-12. The Royal Air Force sent two F.2Bs to McCook Field to be used as “pattern aircraft.” These were assigned project numbers P30 and P37.³
The Engineering Division at McCook Field found that the Liberty was too heavy to be practical when installed in the Bristol F.2, and other engine types were considered. One of the pattern aircraft was modified to accept a 300 horsepower Hispano-Suiza V-8 engine.
P37 was the project number assigned to the second of the two Bristol F.2B fighters evaluated at Wright Field in 1918.
When equipped with the Hispano-Suiza V-8 engine, the modified F.2B had an empty weight of 1,733 pounds (786 kilograms), and maximum of 2,630 pounds (1,193 kilograms). It had a maximum speed of 128 miles per hour (206 kilometers) per hour at Sea Level; 105 miles per hour (169 kilometers per hour) at 10,000 feet, 100½ miles per hour (162 kilometers per hour) at 13,000 feet, and 97½ miles per hour (157 kilometers per hour) at 15,000 feet. With the Hispano, the F.2B could climb to 1,000 feet in 1 minute, 10 seconds, 10,000 feet in 15 monutes, 5 seconds, 15,000 feet in 28 minutes and 50 seconds.
Three-view illustration for the Bristol F.2B. (Flight)
¹ FAI Record File Number 15463: 9,455 meters (31,020 feet)
² FAI Record File Number 15671: 9,455 meters (31,020 feet)
³ A source states that P30 carried the RAF identification number C949, and that P37, C4729.
Enterprise rollout at Palmdale, California, 17 September 1976. (Roger Ressmeyer/CORBIS)
17 September 1976. Enterprise (OV-101), the prototype Space Shuttle Orbital Vehicle, was rolled out at the Rockwell International plant at Palmdale, California.
X-15 56-6670 is carried under the right wing of NB-52A 52-003. Scott Crossfield is in the cockpit of the rocket plane. (NASA)
17 September 1959: After previously making one glide flight, North American Aviation Chief Engineering Test Pilot Albert Scott Crossfield made the first powered flight of an X-15 hypersonic research rocket plane.
Carried aloft under the right wing of an eight-engine Boeing NB-52A Stratofortress bomber, USAF serial number 52-003, the first of three North American Aviation X-15s, 56-6670, was airdropped from 35,000 feet (10,668 meters) over Rosamond Dry Lake, west of Edwards Air Force Base. Launch time was 08:08:48.0 a.m., Pacific Daylight Savings Time (15:08.48.0 UTC).
Scott Crossfield prepares for a flight in the North American Aviation X-15A. Crossfield is wearing a conformal (face seal) helmet with his David Clark Co. MC-2 full-pressure suit. (NASA/North American Aviation, Inc.)
The X-15 was designed to use the Reaction Motors XLR-99 rocket engine, but early in the test program that engine was not yet available so two smaller XLR-11 engines were used. This was engine the same type used in the earlier Bell X-1 rocket plane that first broke the sound barrier in 1948. Though producing just one-fourth the thrust of the XLR-99, it allowed the functional testing of the X-15 to proceed.
The X-15’s two Reaction Motors XLR11 engines. (NASA)
Scott Crossfield wrote:
Two minutes after launch I reached 50,000 feet and pushed over in level flight. Then I dropped the nose slightly for a speed run, meanwhile maneuvering the ship through a series of turns and rolls, conscious of a deep rumbling noise of the rocket and a great rush of wind on the fuselage. It was obvious the black bird was in her element at supersonic speeds. She responded beautifully. I stared in fascination at the Mach meter which climbed from 1.5 Mach to 1.8 Mach and then effortlessly to my top speed for this flight of 2.3 Mach or about 1,500 miles and hour. Then, because I was under orders not to take the X-15 wide open, I shut off three of the rocket barrels. As I slowed down, I recalled the agony at Edwards many years before when we had worked for months pushing, calculating, polishing and who knows what else to achieve Mach 2 in the Skyrocket. Now with the X-15 we had reached that speed in three minutes on our first powered flight and I had to throttle back.
—Always Another Dawn, The Story Of A Rocket Test Pilot, by A. Scott Crossfield with Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960. Chapter 39 at Pages 362.
X-15A 56-6670 drops from the wing of the B-52 mothership. The vapor trail is from hydrogen peroxide that powers the aircraft power systems. Note the roll to the right as the X-15 drops from the pylon. (NASA)
The X-15 dropped 2,000 feet (610 meters) while Scott Crossfield ignited the two XLR-11 engines and then started “going uphill.” During the 224.3 seconds burn duration, the X-15 reached Mach 2.11 (1,393 miles per hour/2,242 kilometers per hour) and climbed to 52,300 feet (15,941 meters), both slightly higher than planned.
Problems developed when the rocket engine’s turbo pump case failed, and fire broke out in the hydrogen peroxide compartment, engine compartment and in the ventral fin. Crossfield safely landed on Rogers Dry Lake at Edwards Air Force Base. The duration of the flight was 9 minutes, 11.1 seconds. Damage to the rocket plane was extensive but was quickly repaired. 56-6670 flew again 17 October 1959.
Chief Engineering Test Pilot A. Scott Crossfield climbs out of the cockpt of a North American Aviation X-15A hypersonic research rocketplane. (Der Spiegel)
Over the next nine years the three X-15s would make 199 flights, setting speed and altitude records nearly every time they flew, and expanding NASA’s understanding of flight in the hypersonic range. The first two X-15s, 56-6670 and 56-6671, survived the program. 670 is at the Smithsonian Institution National Air and Space museum and 671 is at the National Museum of the United States Air Force.
Test pilot Albert Scott Crossfield with X-15 56-6670 attached to the right wing pylon of NB-52A 52-003 at Edwards Air force Base. (North American Aviation Inc.)
