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.
Mikoyan Design Bureau E-155MP 83/1 (OKB Mikoyan)Alexander Vasilyevich Fedotov
16 September 1975: Alexander Vasilyevich Fedotov, Mikoyan Experimental Design Bureau’s chief test pilot, took the Product 83 prototype, E-155MP 83/1, for its first flight.
Project 83 was a two-seat, twin-engine, Mach 2.8+ interceptor, designed as a successor to the Mikoyan-Gurevich MiG 25 “Foxbat” and would be designated the MiG 31. The Soviet Ministry of Defense assigned odd numbered designators to fighter-type aircraft, while NATO, the North Atlantic Treaty Organization, gave them identifying names beginning with the letter F. NATO calls the MiG 31 “Foxhound.”
The E-155MP is 22.69 meters (77 feet, 5 inches) long with a wingspan of 13.46 meters (44 feet, 2 inches) and overall height of 5.15 meters (16 feet, 11 inches). Its empty weight is 20,800 kilograms (45,856 pounds), normal takeoff weight 40,600 kilograms (89,508 pounds) and maximum takeoff weight of 46,000 kilograms (101,413 pounds).
Mikoyan Design Bureau E-155MP, 83/1, first prototype of the MiG-31 Foxhound. (Mikoyan Experimental Design Bureau)
The aircraft is powered by two low-bypass-ratio Soloviev Design Bureau D-30 F6 turbofan engines, producing 91.00 kN (20,458 pounds of thrust), each, and 152.00 kN (34,171 pounds thrust), each, with afterburners.
The E-155MP had a maximum speed of Mach 2.82 (2,995 kilometers per hour/1,861 miles per hour) at 17,500 meters (57,415 feet) and 1500 (932 miles per hour) at low altitude. The prototype’s service ceiling was 20,000 meters (65,617 feet), and it had a range of 2,150 kilometers (1,336 miles).
The aircraft is unsuitable for air combat manuevering. The airframe is limited to a load factor of 5 Gs.
Mikoyan Design Bureau E155MP 83/1 (OKB Mikoyan)
The production MiG 31 is armed with one Gryazev-Shipunov GSh-6 23 23mm six-barrel rotary cannon with 260 rounds of ammunition. Four Vympel R-33 long-range air-to-air missiles are carried in fuselage recesses, and various combinations of short and medium range missiles can be carried on pylons under the wings.
The MiG 31 was in production from 1979 until 1994. Beginning in 2010, a modernization program to bring the up to the MiG 31BM configuration. It is believed that approximately 400 MiG 31 interceptors are in service.
A Russian Air Force MiG 31. (Dmitriy Pichugin via Wikipedia)
Alexander Vasilievich Fedotov born 23 June 1932 at Stalingrad, Russia (renamed Volgograd in 1961). He graduated from the Air Force Special School at Stalingrad, and in 1950, entered the Soviet Army. Fedotov attended the Armavir Military Aviation School of Pilots at Amravir, Krasnodar Krai, Russia, graduating in 1952, and then became a flight instructor. In 1958 he attended the Ministry of Indutrial Aviation Test Pilot School at Zhukovsky. He was a test pilot for the Mikoyan Experimental Design Bureau from 1958 to 1984. In 1983, Alexander Fedotov was promoted to the rank of Major General in the Soviet Air Force.
On 22 July 1966, Fedotov was honored as a Hero of the Soviet Union. He was named an Honored Test Pilot of the Soviet Union, 21 February 1969. He was qualified as a Military Pilot 1st Class. Fedotov was twice awarded the Order of Lenin, and also held the Order of the Red Banner and the Order of the Red Banner of Labor.
During his career as a test pilot, Major General Fedotov had been forced to eject from an airplane three times. He had also set 15 Fédération Aéronautique Internationale world records for speed, altitude and time to altitude. One of these, FAI Record File Number 2825, in which he flew a Mikoyan E-266M to 37,650 meters (123,534 feet), 31 August 1977, remains the current record. The FAI has also honored him three times with The De la Vaulx Medal (1961, 1973 and 1977), and in 1976 awarded him the FAI’s Gold Air Medal.
Major General Alexander Vasilyevich Fedotov and his navigator, Valerie Sergeyvich Zaytevym, were killed when the second MiG 31 prototype, number 83/2, crashed during a test flight. Neither airman was able to eject.
Major General Alexander Vasilyevich Federov, Hero of the Soviet Union
North American Aviation NA-246 Sabreliner prototype, N4060K, during its first flight, 16 September 1958. (North American Aviation, Inc.)
16 September 1958: At Palmdale, in the high desert of southern California, the prototype North American Aviation, Inc., Model NA-246 Sabreliner, N4060K, took off on its first flight. The test pilots were James O’Connor (“J.O.”) Roberts, Jr., and George Mace. Following the flight, Roberts said, “The airplane handled exceptionally well in every maneuver we tried.”
The Sabreliner had been designed and built at North American’s expense to meet the U.S. Air Force specification for the UTX, a twin-engine jet that would be primarily used as a trainer for Air Force pilots in non-flying assignments but who needed to remain proficient. It could also be used as a passenger and cargo transport.
The NA-246 was flown by two pilots and could carry up to four passengers in “club seating.”
In October 1958, the Air Force ordered the Model 265 Sabreliner into production, designated T-39A-1-NA (Serial numbers 59-2868 to -2871). This aircraft could carry up to 7 passengers. In 1962, a commercial variant of the T-39A, the Model 265 Sabreliner, was certified by the Federal Aviation Administration.
North American Aviation Model 256, N4060K, during its first flight, 16 September 1958. (North American Aviation, Inc.)
The T-39A was 44 feet (13.411 meters) long, with a wingspan of 44 feet, 6 inches (13.564 meters) and overall height of 16 feet (14.874 meters). The wings were swept at 28°. It had an empty weight of approximately 9,250 pounds (4,196 kilograms) and maximum takeoff weight of 17,760 pounds (8,056 kilograms).
The Model 246 prototype was powered by General Electric J85 turbojet engines which produced about 2,000 pounds of thrust (8.90 kilonewtons). The the production T-39A used Pratt & Whitney J60-P-3 engines, rated at 3,000 pounds (13.34 kilonewtons) for takeoff.
The T-39A had a maximum allowable airspeed (VMO) of 350 knots, indicated (KIAS) (403 miles per hour/648 kilometers per hour) from Sea Level to 21,100 feet (6,431 meters). Above that altitude, speed was restricted to 0.77 Mach.
North American Aviation T-39A-1-NA, 62-4478, at the National Museum of the United States Air Force.. (U.S. Air Force)
The prototype was issued an Airworthiness Certificate by the Federal Aviation Administration 25 April 1958. The registration was cancelled 30 June 1970.
James O’Connor Roberts, Jr. (Test & Research Pilots, Flight Test Engineers)
James O’Connor Roberts, Jr., was born 17 April 1924 at Washington, D.C. He was the second son of James O’Connor Roberts, an attorney employed by the United States government, and Leah Irene Harris Roberts. He attended the Peddie School in Highstown, New Jersey, and Yale University, where he was a member of the Kappa Phi Sigma (ΚΦΣ) and Chi Psi (ΧΨ) fraternities.
Roberts enlisted in the United States Army Air Forces as an aviation cadet in February 1943.¹ He had blond hair and blue eyes, was 5 feet, 10½ inches (1.79 meters) tall and weighed 145 pounds (65.8 kilograms). He graduated from pilot training 7 January 1944 and was commissioned as a second lieutenant.
Second Lieutenant James O. Roberts, Jr., married Miss Evelyn Meryle Foss Johnson 19 January 1944 at the Walter Reed Memorial Chapel in Washington, D.C. The ceremony was officiated by Chaplain George F. Cotton. They would have four sons. (Mrs. Roberts later died and he remarried.)
Lieutenant Roberts was assigned to the Aleutian Islands where he flew the Curtiss-Wright P-40 Warhawk.
Following World War II, Lieutenant Roberts returned to Yale to complete his studies, graduating in 1946. He majored in Sociology.
North American Aviation F-86A-5-NA Sabre 48-273, 335th Fighter-Interceptor Squadron, 4th Fighter-Interceptor Group, in the markings of the Silver Sabres Aerobatic Team, at Langley Air Force Base, circa 1950. (U.S. Air Force)
Remaining in the Air Force after the war, he transitioned to the North American P-51 Mustang and the Lockheed P-80 Shooting Star. Assigned to the 4th Fighter Group at Andrews Air Force Base, he was a member of the USAF Champion Gunnery Team and the Silver Sabres Aerobatic Team, flying “slot” and solo. The team flew the North American Aviation F-86A Sabre.
4th Fighter-Interceptor Group North American Aviation F-86A Sabres at Suwon, Korea, June 1951. (U.S. Department of Defense VIRIN: HD-SN-99-03072)
The 4th Fighter-Interceptor Group deployed to Korea in 1950. On 22 December 1950, Captain Roberts was flying one of eight F-86As in an air battle against fifteen Mikoyan-Gurevich MiG-15 fighters. Roberts shot down one of the six MiGs destroyed in the battle. No Sabres were lost. He later shot down a second MiG-15.
Major Roberts resigned from the Air Force in March 1952 and joined North American Aviation as an engineering test pilot. He was involved in testing the F-86H fighter bomber variant of the Sabre, the F-100A Super Sabre, and the F-107A. Roberts was a founding member of the Society of Experimental Test Pilots.
Roberts retired from North American after thirty years.
James O’Connor Roberts, Jr., died at Salinas, California, 6 September 2008, at the age of 84 years.
¹ The Department of Veterans Affairs gives an enlistment date of 17 April 1937.
The prototype VS-300 helicopter clears the ground for the first time, 14 September 1939. Igor Sikorsky is at the controls. His right foot rests on the anti-torque pedal. (Sikorsky Historical Archives)
14 September 1939: At Stratford, Connecticut, Igor Sikorsky made the first tethered flight of the Vought-Sikorsky VS-300 prototype helicopter. The duration of the flight was just 10 seconds but demonstrated that the helicopter could be controlled.
The Vought-Sikorsky VS-300 was the first successful single main rotor, single tail rotor helicopter.
The three-bladed main rotor had a diameter of 28 feet (8.534 meters) and turned approximately 255 r.p.m. The rotor turned clockwise as seen from above (the advancing blade is on the left). This would later be reversed. A counter-weighted single blade anti-torque rotor with a length of 3 feet, 4 inches (1.016 meters) is mounted on the left side of the monocoque beam tail boom in a pusher configuration and turns counter-clockwise as seen from the helicopter’s left (the advancing blade is above the axis of rotation).
Vought-Sikorsky VS-300 under construction, 8 September 1939. (Sikorsky Historical Archives)
In the initial configuration, the VS-300 was powered by an air-cooled, normally-aspirated, 144.489-cubic-inch-displacement (2.368 liter) Lycoming O-145-C3 horizontally-opposed, four-cylinder, direct-drive engine with a compression ratio of 6.5:1. It was rated at 75 horsepower at 3,100 r.p.m., using 73-octane gasoline. It was equipped with a single Stromberg carburetor and dual Scintilla magnetos. The dry weight of the O-145-C3 was 167 pounds (75.75 kilograms). Later in the VS-300’s development, the Lycoming was replaced by a 90-horsepower Franklin 4AC-199 engine.
On 19 December 1939, the VS-300 was rolled over by a gust of wind and damaged. It was rebuilt, however, and developed through a series of configurations. It made its first free (untethered) flight 13 May 1940.
Test flights continued for several years. After 102 hours, 32 minutes, 26 seconds of flight, the VS-300 was donated to the Henry Ford Museum, Dearborn, Michigan.
Igor Sikorsky adjusts his fedora while at the controls of the VS-300. (Sikorsky Historical Archives)
The Gloster G.37, prototype of the Gloster Gladiator Mk.I (Gloster Aircraft Co., Ltd.)
12 September 1934: Hawker Aircraft Company test pilot Flying Officer Phillip Edward Gerald Sayer made the first flight of the Gloster G.37, a prototype fighter for the Royal Air Force, designed to reach a speed of 250 miles per hour (402 kilometers per hour) while armed with four machine guns. The flight took place at Gloster’s private airfield at Brockworth, Gloucestershire.
The Gladiator was designed by Gloster’s chief designer, Henry Philip Folland.
The Gladiator was a single-place, single-engine, single-bay biplane, with fixed landing gear. The airplane was primarily of metal construction, though the aft fuselage, wings and control surfaces were fabric covered.
The production Gladiator Mk.I was 27 feet, 5 inches (8.357 meters) long with a wingspan of 32 feet, 3 inches (9.830 meters) and overall height of 11 feet, 9 inches (3.581 meters). It had an empty weight of 3,217 pounds (1,459 kilograms) and gross weight of 4,594 pounds (2,084 kilograms).
Gloster G.37 prototype, right profile
The G.37 was equipped with a left-hand tractor, air-cooled, supercharged, 1,519.083 cubic-inch-displacement (24.893 liters) Bristol Mercury IV-S2 nine cylinder radial engine. With a compression ratio of 5.3:1, the IV-S2 was rated at 505 horsepower at 2,250 r.p.m., and 540 h.p. at 2,600 r.p.m., both at 13,000 feet (3,962 meters). It developed a maximum 560 horsepower at 2,600 r.p.m. at 16,000 feet (4,877 meters). The engine had a take-off power rating of 530 horsepower at 2,250 r.p.m., at Sea Level (3-minute limit). The IV-S2 drove a two-bladed fixed-pitch propeller through a 0.655:1 gear reduction. This engine weighed 920 pounds (417 kilograms).
The G.37 was repowered with a Bristol Mercury VI-S engine, which had a 6:0:1 compression ratio and a 0.5:1 gear reduction ratio. This engine produced a maximum of 636 horsepower at 2,750 r.p.m. at 15,500 feet.
The prototype was armed with two synchronized, air-cooled Vickers .303-caliber machine guns, firing forward through the propeller arc, and two .303-caliber Lewis guns mounted under the bottom wing.
With the upgraded engine and armament, the G.37 reached 242 miles per hour (389 kilometers per hour).
The Gloster Gladiator Mk.I with an enclosed cockpit and a Bristol Mercury IX engine had a maximum speed of 257 miles per hour (414 kilometers) per hour) at 14,600 feet (4,450 meters).
This production Gloster Gladiator Mk.I, K6131, shows the cockpit enclosure. (This airplane, the second production Gladiator Mk.I, was damaged beyond repair when it ran out of fuel near RAF Church Fenton, 26 March 1938.) (Royal Air Force)Gloster Gladiator Mk.I L8032. (SDASM)
The Gladiator Mk.I entered service with the Royal Air Force in February 1937. It was the last biplane fighter to do so, and was the first fighter with an enclosed cockpit. Beginning with No. 72 Squadron, eight fighter squadrons were equipped with the type, though by the beginning of World War II, these were being phased out by more modern airplanes like the Hawker Hurricane and Supermarine Spitfire.
A total of 737 Gloster Gladiators, Mk.I and Mk.II, were built. In addition to the Royal Air Force, there were operated by several other countries in Europe, the Mediterranean and the Middle East.
Prototype Gloster Gladiator G.37 in flight, now marked K5200. A .303-caliber Lewis machine gun is visible under the right wing. (Royal Air Force)Phillip E.G. Sayer, O.B.E. (Flight)
Phillip Edward Gerald Sayer was born at Colchester, England, 2 February 1905. He was the second of three children of Edward James Sayer, a retired British Army officer and Ethel Jane Hellyar Sayer.
Sayer was granted a short service commission in the Royal Air Force as a Pilot Officer on probation, 30 June 1924. His rank was confirmed 23 May 1925. He was promoted to Flying Officer 30 March 1926. Flying Officer Sayer was transferred to the R.A.F. Reserve, 2 March 1929.
In 1930, Gerry Sayer joined Hawker Aircraft Company as a test pilot. When Hawker took over Gloster Aircraft Co., Ltd. in November 1934, he was appointed Chief Test Pilot of Gloster.
Flight Lieutenant Sayer completed his service and relinquished his commission, 2 March 1937. He was permitted to retain his rank.
On 15 May 1941, Sayer made the first flight of the Gloster-Whittle E.28/39, a prototype jet fighter.
Chief Test Pilot Phillip Edward Gerald Sayer, Esq., was appointed an Officer of the Most Excellent Order of the British Empire (OBE) in the New Years Honours list, 30 December 1941.
Gerry Sayer was flying a Hawker Typhoon from RAF Acklington, 22 October 1942, to the Druridge Bay gunnery range. He never returned.
