CEN19LA074 · Cessna 172 S

The flight instructors/student pilots of two Cessna airplanes, N565SP and N52243, were each returning from local instructional flights. The N565SP pilot contacted the tower and reported being near the southern tip of a lake, about 10 miles south of the airport; the tower controller instructed the pilot to enter a left downwind for runway 17. About 45 seconds later, the N52243 pilot contacted the tower and reported being 7 miles south of the airport; the tower controller also instructed that pilot to enter a left downwind for runway 17. Radar data indicated that, about this time, the airplanes were within about 0.1 nautical mile laterally and 100 ft vertically of each other. The flightpaths of the airplanes remained in close proximity for about the next 58 seconds (1.6 miles), with the airplanes' altitudes remaining within 100 ft of each other.

About 30 seconds after the N52243 pilot contacted the tower, the N565SP pilot requested verification of the assigned transponder code. During the tower controller's transmission response, an audible conflict alert could be heard in the control tower cab. The controller did not issue a safety alert or advise either airplane's pilots that another airplane was in the same proximity. About 20 seconds later, the controller instructed the N52243 pilot to start a turn toward the northeast corner of the lake. The airplanes then collided, and the N52243 pilot declared an emergency. The N565SP pilot subsequently transmitted that an airplane had "hit us from the back" and that there had been a collision. The pilots of both airplanes maintained control of the airplanes and landed; both airplanes sustained substantial damage during the collision.

Day visual meteorological conditions prevailed. Title 14 Code of Federal Regulations 91.113 requires that, when weather conditions permit, "vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft." The pilots of both airplanes did not maintain an effective traffic scan as they entered the traffic pattern, nor did they exercise the vigilance necessary to see and avoid the other airplane. In addition, Federal Aviation Administration Joint Order 7110.65 indicates that a controller should give first priority to "separating aircraft and issuing safety alerts." The tower controller did not recognize the proximity of the airplanes to each other, provide a safety alert to the pilots of either airplane, or establish a landing sequence that provided proper airplane spacing to the runway.

Verbatim NTSB analysis and probable cause from the NTSB dataset