Page:CAB Accident Report, Mid-Air Collision on 30 September 1959.pdf/5

Rh Considering the relative speeds of the two aircraft, with the Cessna being somewhat faster, the Board believes the two aircraft could maintain this position throughout the traffic pattern until turning onto the final approach. The fact that the Aeronca was on the inside during the turns onto the base and final approach, and therefore traveling the shorter distance, was compensated for by the relatively faster speed of the Cessna. The two 90-degree turns that each made, served to close the gap between the two aircraft and placed the Cessna under the Aeronca on final approach just prior to collision.

The Aeronca pilot stated that because the air was rougher than usual, he was flying at a slightly higher airspeed which tended, to give his aircraft better landing characteristics. When both aircraft were on final approach the tower operator instructed the Cessna pilot by radio not to land. The Cessna pilot acknowledged these instructions and was observed to level off. It was at this point that the collision occurred. Since the Cessna pilot was not told why he was not to land, it can logically be assumed that having received this instruction he leveled the nose of his aircraft and applied power for an aborted landing. The Cessna pilot, having altered his glide angle to level flight and increased his airspeed, overtook and collided with the Aeronca which was descending. The damage to the aileron of the Aeronca and the rudder of the Cessna attests to the fact that the Cessna was moving faster than the Aeronca at the moment of collision.

The tower operator stated an alternating green and red warning light was given the Aeronca pilot while the aircraft was on the downwind leg and while turning on the base leg, and a steady red light was directed toward the Aeronca until the aircraft collided. Whether or not a warning light or a signal to give way or whether such signals were directed to the right aircraft is questionable. The portable traffic lamp was checked immediately after the accident and determined to be in proper working order. It is possible that a warning light was given while both aircraft were on the downwind leg. With both pilots at this time concentrating on the landing end of the runway and with the tower positioned off to the rear of each pilot's left shoulder, it is reasonable to assume that a light given while the aircraft were in this position could have been missed by both pilots. When both aircraft turned onto base leg, their positions would have enabled their pilots to see the warning light if given, which, according to the tower controller, was meant for the pilot of the Aeronca which he believed was the second aircraft.

When the two aircraft turned onto final approach, the possibility of either pilot seeing a light signal from the tower is greatly increased. Yet neither pilot took action indicative of his having seen a light signal. It is reasonable to assume that had the Cessna pilot seen a red warning light shining in his direction he would have used his radio to inquire whether it was meant for him. Had the Aeronca pilot seen the light he would have discontinued his approach and circled to the left.

It is entirely possible that the reason for neither pilot seeing a light was because the tower operator directed the light to the second aircraft, which was the Cessna 140, while mistakenly thinking it was the Aeronca L-16. Since the Cessna pilot was receiving his instructions by radio, it is unlikely that he would be observant of a light signal from the tower.