Background
A Piper PA-30 and a Cessna 150H collided in flight while in the traffic pattern at Clearwater Airpark (KCLW). Visual meteorological conditions prevailed at the time of the accident. Examination of both airplanes revealed no preimpact failure or malfunction of the flight controls, and the Cessna's engine showed no abnormalities.
Sequence of Events
The pilot of the Piper reported that after canceling his IFR clearance, the controller warned him of numerous traffic near Clearwater. The pilot acknowledged, changed his radio to 123.0 MHz (the CTAF for KCLW), and began monitoring for traffic. He crossed the center of the airport from east to west at 1,500 feet. Once on the west side, he made a left turn and started descending to traffic pattern altitude, announcing his intentions to enter a left crosswind for runway 16. The flight turned onto the downwind leg, and he announced that on the radio. He reported no traffic observed up to that point.
When the flight was approximately two-thirds down the downwind leg, the passenger shouted "look out." The Piper pilot looked right and saw an airplane so close he could not react before the collision. He lost control momentarily, then glimpsed the aircraft to his left.
A witness east of the crash site reported seeing a Cessna fly over his location south-southeast bound, then bank right toward a north-northwesterly direction. He also observed the Piper flying briefly in a southeasterly direction, then bank left toward a north-northwesterly direction.
An individual on the ground at the destination airport heard the Piper pilot make repetitive radio calls on the CTAF, announcing his intention to land on runway 16. The same individual, who personally knew the Cessna pilot, reported hearing him announce crossing midfield at KCLW. The Cessna pilot did not report altitude or intention, and no other radio calls from the Cessna were heard. No record of communications from the Cessna pilot to any FAA Air Traffic Control Facility existed.
Radar data after the collision showed the Piper flew downwind, base, then final approach to runway 16. The Cessna crash site was near the last radar target.
Post-Accident Examination
Examination of the Piper revealed paint transfer and damage to the right wing, vertical stabilizer, and upper surface of the left horizontal stabilator. Paint transfer was noted on the bottom fuselage skin of the Cessna near the landing gear attach point area. The Piper's No. 1 communication transceiver was set to 123.00 MHz and operated satisfactorily when tested postaccident. The Cessna's only communication transceiver was set to 123.00 MHz; during postaccident testing it operated momentarily, but impact damage precluded continued testing.
The AIM indicates to enter the traffic pattern at a 45-degree angle to the runway on the downwind leg, but the source does not state whether this was a factor.
No probable cause was stated in the source.