valid private pilot certificate and had accumulated a total of 122 flying hours.
The field elevation of North Philadelphia Airport is 120 feet; the recommended traffic is left, to be flown at an altitude of 1,000 feet above the ground.
The pilot of the Aeronca said that after returning to the airport he was on his third or fourth touch-and-go approach to runway 15 and had not received any light signals from the tower since receiving a green light for the original takeoff. Several aeronautically experienced groundwitnesses, who were seated on a bench directly in front of the tower at the time, observed the aircraft making touch-and-go landings. According to these witnesses, both aircraft were observed to be in close proximity to one another while they were on their down-wind, base, and final approach. These witnesses place the Aeronca inside of, ahead of, and at approximately the same altitude as the Cessna when observed on the downwind leg.
After clearing the Cessna via radio for landing on runway 15, the tower operator located the aircraft visually on the downwind leg. He also observed another aircraft which he identified as the Aeronca, which, he states, was outside of, above, and behind the Cessna. He did not observe the Aeronca practicing touch-and-go landings prior to this time.
The following testimony was given by the two tower operators on duty: An alternate green and red warning light[1] was given to what they believed to be the Aeronca while it was on the downwind leg and while the aircraft was turning onto the base leg. No instructions or advisories were issued via radio to the Cessna pilot as he traversed the downwind and base leg. The light was changed to steady red[2] which was directed toward the Aeronca until the aircraft collided. No subsequent radio contacts were made with the Cessna pilot, following the initial issuance of landing instructions, until just prior to the collision when the Cessna pilot was told, "Do not land." An exchange of conflicting traffic or reason for cancellation of the original landing clearance was not given to the pilot of the Cessna. The Cessna then acknowledged the message, leveled off, and continued straight ahead.
According to the Aeronca pilot, no lights from the tower were observed by him at any tine during this approach, nor during any of his previous approaches and touch-and-go landings. The only light signals transmitted by the tower during his previous touch-and-go landings was the green light for the original take-off clearance.
The midair collision occurred approximately 500 feet from the approach end of the runway 15 while both aircraft were lined up on their final approach. The Cessna was directly below and a little to the right of the Aeronca. The Aeronca
