12 May 1953: A Boeing B-50A-5-BO Superfortress, 46-011, modified to carry a Bell X-2 supersonic research rocketplane, was engaged in a captive test flight at 30,000 feet (9,144 meters) over Lake Ontario, between Canada and the United States. The number two X-2, 46-675, was in the bomb bay.
The bomber was equipped with a system to keep the X-2’s liquid oxygen tank filled as the cryogenic oxidizer boiled off. With Bell’s Chief of Flight Research, test pilot Jean Leroy (“Skip”) Ziegler, in the bomb bay above the X-2, the system operation was being tested.
There was an explosion. The X-2 fell from the bomber and dropped into Lake Ontario, between Trenton, Ontario, Canada, and Rochester, New York, U.S. A. Skip Ziegler and an engineer aboard the bomber, Frank Wolko, were both lost. A technician, Robert F. Walters, who was in the aft section of the B-50 with Wolko, was badly burned and suffered an injured eye.
The B-50’s pilots, William J. Leyshon and David Howe, made an emergency landing at the Bell Aircraft Corporation factory airport at Wheatfield, New York (now, the Niagara Falls Internatonal Airport, IAG). The bomber was so heavily damaged that it never flew again.
Heavy fog over the lake hampered search efforts. Neither the bodies of Ziegler and Wolko or the wreckage of the X-2 were found.
After a series of explosions of early rocketplanes, the X-1A, X-1-3, X-1D and the X-2, investigators discovered that leather gaskets which were used in the fuel system had been treated with tricresyl phosphate (TCP). When this was exposed to liquid oxygen an explosion could result. The leather gaskets were removed from the other rocketplanes and the explosions stopped.
The X-2 was a joint project of the U.S. Air Force and NACA (the National Advisory Committee on Aeronautics, the predecessor of NASA). The rocketplane was designed and built by Bell Aircraft Corporation of Buffalo, New York, to explore supersonic flight at speeds beyond the capabilities of the earlier Bell X-1 and Douglas D-558-II Skyrocket. Two X-2s were built.
In addition to the aerodynamic effects of speeds in the Mach 2.0–Mach 3.0 range, engineers knew that the high temperatures created by aerodynamic friction would be a problem, so the aircraft was built from stainless steel and K-Monel, a copper-nickel alloy.
The Bell Aircraft Corporation X-2 was 37 feet, 10 inches (11.532 meters) long with a wingspan of 32 feet, 3 inches (9.830 meters) and height of 11 feet, 10 inches (3.607 meters). Its empty weight was 12,375 pounds (5,613 kilograms) and loaded weight was 24,910 pounds (11,299 kilograms).
The X-2 was powered by a throttleable two-chamber Curtiss-Wright XLR25-CW-1 rocket engine that produced 2,500–15,000 pounds of thrust (11.12–66.72 kilonewtons)
Rather than use its limited fuel capacity to take off and climb to altitude, the X-2 was dropped from a modified heavy bomber as had been the earlier rocketplanes.
The launch altitude was 30,000 feet (9,144 meters). After the fuel was exhausted, the X-2 glided to a touchdown on Rogers Dry Lake at Edwards Air Force Base.
The X-2 reached a maximum speed of Mach 3.196 (2,094 miles per hour/3,370 kilometers per hour) and maximum altitude of 126,200 feet (38,466 meters).
Bell X-2 46-675 on its transportation dolly at Edwards Air Force Base, California, 1952. (NASA)
12 May 1938: Three Boeing B-17 Flying Fortress four-engine bombers of the 49th Bombardment Squadron, 2nd Bombardment Group, departed Mitchel Field, Long Island, New York in heavy rain and headed eastward over the Atlantic Ocean. Their mission, assigned by Major General Frank M. Andrews, commanding General Headquarters, U.S. Army Air Corps, was to locate and photograph the Italian passenger liner, SS Rex, then on a transatlantic voyage to New York City. The purpose was to demonstrate the capabilities and effectiveness of long-range bombers.
The flight was led by Major Caleb V. Haynes, commanding officer of the 49th Bombardment Squadron, flying B-17 number 80. The 2nd Bomb Group commanding officer, Lieutenant Colonel Robert Olds, was aboard Haynes’ B-17, along with an NBC radio crew to broadcast news of the interception live across the country. Reporters from the New York Times and the New York Herald Tribune were aboard the other airplanes.
The planning of the interception and in-flight navigation was performed by First Lieutenant Curtis E. LeMay. Position reports from SS Rex were obtained and forwarded to LeMay as the aircraft were taxiing for takeoff. The flight departed Mitchel Field at 8:45 a.m. They encountered heavy rain, hail, high winds and poor visibility, but at 12:23 p.m., the Flying Fortresses broke out of a squall line and the passenger liner was seen directly ahead. They flew alongside the ship at 12:25 p.m., 620 nautical miles (1,148.24 kilometers) east of Sandy Hook, New York. They were exactly on the time calculated by Lieutenant LeMay. The B-17s made several passes for still and motion picture photography while NBC broadcast the event.
Colonel Olds would rise to the rank of Major General and command 2nd Air Force during World War II. He was the father of legendary fighter pilot Brigadier General Robin Olds. Major Hayes served in various combat commands and retired at the rank of Major General in 1953.
Curtis LeMay would be a Major in command of the 305th Bombardment Group, a B-17 unit, at the beginning of World War II. He personally led many combat missions over Europe, and would command the 4th Bombardment Wing and then the 3rd Air Division. By the end of the war, he was in command of the XXI Bomber Command based in the Marianas Islands. From 1948 to 1957, General LeMay commanded the Strategic Air Command, then served as Vice Chief of Staff of the Air Force. From 1961 to 1965, LeMay was Chief of Staff.
At the time of the interception of the Rex, there were only 12 B-17s in the Air Corps inventory: the original Y1B-17 development aircraft. By the end of production in 1945, 12,731 B-17 Flying Fortresses had been built by three aircraft manufacturers.
The Boeing B-17 (Model 299B, previously designated Y1B-17, and then YB-17) was a pre-production service test prototype. Thirteen had been ordered by the Air Corps. It was 68 feet, 4 inches (20.828 meters long with a wingspan of 103 feet, 9⅜ inches (31.633 meters) and the overall height was 18 feet, 4 inches (5.588 meters).
The YB-17 was powered by four air-cooled, supercharged 1,823.129-cubic-inch-displacement (29.876 liter) Wright Aeronautical Division Cyclone R-1820G5 (R-1820-39) nine-cylinder radial engines with a compression ratio of 6.45:1. The R-1820-39 had a Normal Power rating of 805 horsepower at 2,100 r.p.m. at Sea Level, and 930 horsepower at 2,200 r.p.m. for Takeoff, burning 92-octane gasoline. A long carburetor intake on top of the engine nacelles visually distinguishes the YB-17 from the follow-on YB-17A. The engines drove three-bladed Hamilton Standard constant-speed propellers through a 16:11 gear reduction. The R-1820-39 was 3 feet, 9-7/16 inches (1.154 meters) long and 4 feet, 6¼ inches (1.378 meters) in diameter. It weighed 1,198 pounds (543.4 kilograms).
The YB-17 had an empty weight of 24,465 pounds (11,097 kilograms), gross weight of 34,880 pounds (15,821 kilograms) and maximum takeoff weight of 42,600 pounds (19,323 kilograms). The maximum speed was 256 miles per hour (412 kilometers per hour) at 14,000 feet (4,267 meters). Its service ceiling was 30,600 feet (9,327 meters) and the maximum range was 3,320 miles (5,343 kilometers).
The YB-17 could carry 8,000 pounds (3,629 kilograms) of bombs. Defensive armament consisted of five air-cooled Browning .30-caliber machine guns.
12 May 1902: Aeronaut Augusto Severo de Albuquerque Maranhão and engineer Georges Saché lifted off aboard the semi-rigid airship Pax, which Severo had designed, at Vaugirard, Paris.
This was Severo’s second airship. He had designed and built a larger craft, Bartolomeu de Gusmão, eight years earlier in Brazil. It had been destroyed by gusty winds. After raising enough to build a new ship, he went to Paris. His new airship was a semi-rigid keel-and-girder type. The envelope was silk but it was given some rigidity by a structure of bamboo.
The craft was approximately 30 meters (98.4 feet) long and 12.4 meters (40.7 feet) in diameter. The volume of the hydrogen gas used for buoyancy was about 2,330 cubic meters (82,283 cubic feet). A gondola was suspended below.
Though he had planned to power the craft with electric motors and batteries, time and money forced Severo to substitute internal combustion engines. Pax was propelled by two Société Buchet engines, with a 24-horsepower engine driving a 6 meter (19.7 feet), two-bladed propeller in a pusher configuration at the rear, and a second, 16 horsepower engine driving a 5 meter (16.4 feet) propeller in tractor configuration at the front of the airship. The propellers turned at 50 r.p.m.
Augusto Severo had designed both of his airships with a new method which increased their stability in flight. The gondola, rather than being suspended by ropes or cables, was rigidly attached to the envelope above with a structure of bamboo. This structure continued inside the envelope from front to rear and formed a trapezoid. This prevented the oscillation that was common with a more flexible arrangement.
Very early on the morning of 12 May 1902, Augusto Severo took his new airship on its first flight. It soon reached approximately 1,200 feet (365 meters). It then exploded, caught fire and fell to the ground near Monteparnasse Cemetery. The descent took approximately 8 seconds. Both men were killed.
A contemporary newspaper article reported the accident:
M. SEVERO AND HIS ASSISTANT KILLED.
TERRIBLE SCENE IN MID-AIR
At an early hour one morning recently all Paris was startled by the report that M. Severo, the Brazilian deputy, and his assistant, M. Sachet, had been killed while making an excursion in the steerable balloon Pax.
M. Severo and his mechanician left the balloon shed, which is behind the Montparnasse Railway Station, at half-past five in the morning in the Pax. The Brazilian, in his eagerness to make the free ascent, had slept alongside the balloon for the last few nights, waiting until the weather should be entirely propitious.
At daybreak he decided that the favourable moment had arrived. Workmen were hastily summoned, the last preparations completed, and the motors started. The Pax left the shed of M. Lachambre for her first free voyage in the air.
The Brazilian deputy, who was naturally of a gay and genial temperament, was delighted with the ideal morning. He and M. Sachet got the machinery ready, while M. Lachambre and his assistants held on the guide-rope, until Pax should be clear of the surroundings.
As M. Severo cried “Let go!” amid much fluttering of handkerchiefs the Pax rose quietly and steadily, and the calm, blue sky seemed to promise a pleasant excursion.
For the first few minutes all went well, and the motors seemed to be working satisfactorily. The airship answered the helm readily and admiring exclamations rose from the crowd. “Let’s follow her,” cried those on bicycles and motor-cars, and immediately a mad race commenced in the direction taken by the balloon.
But as the Pax rose higher she was seen to fall off from the wind, while the aeronaut could be seen vainly endeavouring to keep her head on.
Then M. Severo commenced throwing out ballast, and M. Lachambre, anxiously watching the balloon from his premises remarked that something had evidently gone wrong.
THE AIRSHIP IN FLAMES.
All this time the Pax was gradually soaring higher and higher, until, just as the balloon was over the Montparasse cemetery, at the height of probably 2000ft, a sheet of flame was seen to shoot up from one of the motors, and instantly the immense silk envelope, containing 9000 cubic feet of hydrogen gas, was enveloped in leaping tongues of fire.
The aeronauts were distinctly seen to be gesticulating despairingly, but no mortal aid could reach them.
As soon as the flames came in contact with the gas, a tremendous explosion followed, an din an instant all that was left of the beautiful airship fell with lightning swiftness to the earth.
“I shall never be able to forget the awful sight,” said a spectator; “it made me dizzy, and I was compelled to turn my head away. When I looked again everything had disappeared, and all the people in the street were running towards the spot where the balloon had fallen.
“When I reached the Avenue du Maine the Pax, mangled beyond description, was lying across the street almost at the corner of the Rie de la Gaite, and the two ill-fated passengers lay dead amid the ruins. M. Severo had fallen on his feet. The upper part of his face was uninjured, but blood was flowing from his mouth an dears. The lower part of his body was crushed and horribly mutilated.
“Near him was Sachet, who had fallen on his face, which was dreadfully burned and congested. His hands, and, in fact, his whole body were covered with blisters where he had been burned, and he had also sustained several fractures. It was a gruesome sight, and it must have been a fearful death.”
A TERRIFIC REPORT.
“The noise of the explosion,” declared one spectator, “made me jump out of bed. I thought of Martinique and wondered if out turn had come, and when I ran to the window, there were two men lying, crushed beneath the remainder of the balloon.”
Another bystander told how Mme. Severo, wife of the aeronaut, whom he had laughingly kissed only twenty minutes before he met his death, fell unconscious to the ground as she witnessed the calamity which overtook her husband.
Poor woman! He had embarked his all in the airship which carried him to his death, and now she is left with seven children and no resources.
M. SANTOS DUMONT’S OPINION.
“I cannot tell you how very sorry I feel at what has happened, ” says M. Santos Dumont, “but I am not greatly surprised. M. Severo did not know anything about airships. He had only been up once or twice in his balloon, and was quite incapable of managing it. The fact that he commenced throwing out ballast when the balloon was going up showed how little he knew.
“Then his escape-valve was only about three yards from the motor, and my opinion is that, as in going up the balloon dilates and the gas must escape through the valve, in so escaping it came in contact with the motor, which was far too near the balloon, and that caused the explosion. Or if the valve did not work, the balloon may have burst and the gas immediately took fire; but a balloon must be built very stupidly to catch fire.
“From the construction of the Pax, however, it seems to me as if it had been made on purpose to kill somebody.”
M. Severo was thirty-eight years old and a member of the Brazilian Parliament. After the catastrophe his watch was found flattened in his waistcoat pocket. It had stopped at 5.40 a.m., the moment of the accident. The body will be taken to Rio Janeiro for interment. His fellow victim, the mechanic Sachet, was only twenty-five years of age and unmarried.
The balloon which began and ended its career in disaster was cigar-shaped, 100ft long, and 36ft in diameter. It was driven by screw fore and aft.
— The Star, Christchurch, New Zealand, Monday 30 June 1902, No. 7411, Page 2, Column 7. (The photographic images are from other sources and were not a part of the newspaper article.)