Page:CAB Accident Report, Mid-Air Collision on 30 September 1959.pdf/3

Rh continued to descend after the Cessna leveled off and initial impact occurred between the forward left wingtip of the Cessna and the underside of the Aeronca right aft lift strut midway at the strut brace position. The Cessna proceeded under the Aeronca's wing and the leading edge of the Cessna's vertical stabilizer contacted the Aeronca's right aileron, bending the Cessna‘s stabilizer and rudder 90 degrees to the right to a flat position. Both aircraft momentarily locked together and entered a bank to the left. The Aeronca managed to turn inside the Cessna and pull up. According to the pilot of the Aeronca, the Cessna then pulled up and struck the Aeronca a second time, this time in the area of the right wing struts. A dent was also made in the underside of the leading edge of the right wing. The Cessna pilot lost control of his aircraft and it plunged to the ground. Collision impact caused binding of the Aeronca‘s right aileron and subsequent partial loss of control. However, the pilot succeeded in landing on runway 15 with no further damage. Ground impact of the Cessna occurred 75 feet from the approach end of runway 15 and 375 feet to the left of the runway 15 centerline.

Weather at the time was scattered clouds at 4,000 feet, high broken clouds; visibility 15 miles; temperature 83°F; surface winds from the south-southeast at 13 knots.

A witness driving an auto stopped on a boulevard approximately 2,500 feet from the end of runway 15 and observed the aircraft pass over his position just prior to the impact. He stated that at this point the Cessna was directly below and to the right of the Aeronca with a vertical separation of approximately 200 feet. All witnesses, including the North Philadelphia Airport tower personnel, agree on that relative position of the two aircraft just prior to impact.

The damage sustained by the Aeronca L-16A was confined to the right wing, the right aileron, and the right lift struts. The right aileron had been stuckstruck [sic] at the trailing edge by the vertical fin of the Cessna. This buckled the diagonal ribs nearest the trailing edge of the aileron, scuffed but did not tear the aileron fabric, and loosened and damaged the internal wing structure forward of the right aileron. No evidence of inflight contact was found on the tail surfaces, fuselage, or landing gear of the Aeronca.

The inflight damage to the Cessna was confined to minor damage to the left wing near the tip, and severe damage to the aft fuselage and tail. The left wingtip damage consisted of a tear in the upper fabric and deformation of the internal rib structure. The shape of this damage matched closely with the shape of the aft jury strut bracket attach bolt and nut from the right wing of the Aeronca. The vertical stabilizer was broken at its base and bent approximately 90 degrees to the right and was generally wrinkled; a leading edge dent appeared 18 inches below the tip. The major portion of the left side of the fin had scratches running up and slightly aft. No evidence of inflight contact between the two aircraft was found on any other part of the Cessna.

The North Philadelphia Airport Control Tower is an FM tower which operates on a 24-hour basis. It is staffed by a chief controller and three air traffic control specialists, all of whom had control tower operator certificates with senior ratings. No scheduled air carriers land or take off from North Philadelphia Airport, and traffic consists mostly of light single and twin-engine transient or locally based aircraft. The tower makes no recordings of radio transmissions or receptions.