Birdwalking Spot

At Hornell, N. Y. last week two seagulls flopped helplessly to earth in the business district, their wings so coated with ice they could not fly. Thawed out by a game warden, they were soon sent on their way. Also last week, the misadventure which overtook two of Nature's best flying mechanisms overtook one of Man's best flying mechanisms 200 miles as the gull flies southwest of Hornell. Just outside of Pittsburgh, a twin-motored Douglas DC2 crippled by ice flopped helplessly to earth killing 13 people in 1937's third major air disaster.

The plane was a Transcontinental & Western airliner which had taken off from Camden, N. J. in perfect mechanical condition with ten passengers, two pilots and a hostess, bound for Pittsburgh's Allegheny Airport. At the wheel was 32-year-old Captain Frederick Lawrence Bohnet, a TWA veteran. The sky was overcast but the weather relatively smooth. Flying above the clouds Capt. Bohnet brought his big ship to Pittsburgh without trouble. At 6:33 p. m. he crossed the airport "cone of silence" at 5,000 ft. out of sight of ground. He was ordered to circle once while another plane came in. "Okay," he replied. For four minutes, as required, he flew west, gradually mushing down through the clouds. The ceiling was about 800 ft. and he broke through it in a slow wheeling turn over the little town of Clifton about three minutes after telling the field he was "okay."

At that point he was spotted by another TWA pilot, Capt. A. M. Wilkins, flying in from the west at 700 ft. ready to land as soon as Bohnet was down. Wilkins saw the silvery monoplane about three miles ahead and 200 ft. lower in level flight. To his surprise he overtook it fast. When only a mile behind, Wilkins cut his speed in order not to pass Bohnet. Simultaneously he noticed that Bohnet was having trouble. Though the air was clear, with no turbulence whatever, the plane ahead was wallowing. A wing would go down five degrees, then wobble back as the other wing dipped. The wallow grew worse. While Wilkins and his co-pilot watched in stricken silence, Capt. Bohnet's plane rolled over on one side as if about to bank, went completely out of control and dived 500 ft. straight down. Wilkins, an old friend of Bohnet, looked away at the last instant, but his co-pilot saw the ship smash into the ground, break into a twisted wreck like a disemboweled fish.

Capt. Wilkins, his voice high with horror, immediately radioed the alarm, then brought his own ship safely in. Meanwhile a dozen other witnesses had swarmed over the wreck. Apparently Capt. Bohnet had killed his engines at the last moment. There was no fire, though gasoline soaked the ground for yards. Telescoped by the terrific blow, the cockpit and cabin were a hash of metal splinters and mangled bodies. All the passengers had been catapulted to the front, all killed instantly. By the time airline officials got there, the crowd had pulled most of the grisly mess apart, taken out the corpses. Only part of the fuselage not mashed beyond recognition was the tail. There, in the jumble of mail pouches, suitcases and parcels, investigators found the private flight log of pretty little Doris Hammons, one of TWA's pioneer hostesses. The last words she had written were: "Sadness must always be for the living. When a ship sets sail it is the eyes of those who watch from shore that are blinded with tears."

Ground witnesses at once began spinning their usual inaccurate stories, but for the first time in years investigators of an air-crash had an expert witness to rely on --Capt. Wilkins. Reaching the scene in a few minutes with his story fresh in their minds, TWA's experts looked at once at the wings, which were sheared off but not smashed. On the leading edge they found traces of where ice had been shaken off by the deicers. Progressing to the ailerons, they discovered a long ridge of ice on the leading edges, not dislodged even by the crash and still an inch and one-half thick though the temperature on the ground was above freezing. That night TWA officially blamed the crash on iced ailerons. Investigators from the Bureau of Air Commerce said nothing but it was taken as tacit agreement when they allowed the wrecked ship to be burned.

One of winter air's greatest perils, icing was supposed to have been conquered by three recent inventions: 1) slinger rings which dribble anti-freeze solution over the propeller blades in flight; 2) heaters which warm and dry the air in the carburetor intake ; 3) rubber overshoes on the leading edges of wing and tail surfaces which pulsate by compressed air, break the ice away as fast as it forms. Until last week ice had never been known to form on ailerons. ,They are the big flaps in the trailing edges of the wings, separated from the wing itself by a four-inch slot. They are used in banking and when one lifts the other drops. They work like rudders on a boat--by the air pressure against them. In Douglas planes the ailerons are the "balanced" type--airfoils which get their efficiency from the smooth play of air across them. The ridge of ice that built up on the leading edge of Capt. Bohnet's ailerons did not jam them, but did change the airfoil shape, thus altering the flow of air across the ailerons to a rough burble which robbed them of their efficiency. As a result, Capt. Bohnet had no control of his wings, could not get out of his turning dive once the plane wobbled into it.

Other transports in the vicinity reported icing conditions but nothing out of the ordinary. Apparently Bohnet's plane passed through a particularly saturated cloud, a spot of "bird-walking weather,"-- just as he dropped through the overcast.

There he picked up the unique coat of ice in a very few seconds. Last week TWA and Douglas both went to work immediately to devise a de-icer for ailerons. "Meanwhile," said TWA's Vice President J. B. Walker, "whenever there are icing conditions, we'll keep our planes on the ground."

*Weather so bad that even birds walk the ground.

This file is automatically generated by a robot program, so reader's discretion is required.