ERA18LA055 · Cessna 182 Q

The commercial pilot of the Piper airplane reported that he had recently performed maintenance on the smoke generator. Before the flight, the Piper pilot coordinated with the pilot of a Cessna to fly adjacent to his airplane to verify whether the Piper's smoke system was operating. After departure, the Piper pilot flew on the right side of and parallel to the Cessna, and both pilots acknowledged each other visually. The Cessna pilot subsequently verified that the Piper's smoke system was operating normally with a "thumbs up" signal, and the Piper pilot then broke off to the right, and the Cessna pilot continued straight ahead.

After clearing for traffic, the Piper pilot then performed a check of the oil system and mixture control, which required inverted flight. He rolled the airplane inverted, verified the system operation, and then rolled the airplane upright, at which point its right wing collided with the Cessna's left wing. The Cessna pilot saw the Piper strike his airplane while in a descent. The Piper pilot stated that he never saw the Cessna and thought he was experiencing a flight control problem after the collision. Both airplanes returned to the departure airport and landed without further incident. The Piper's right wing and aileron and the Cessna's left wing were structurally damaged. The Cessna pilot was flying straight ahead, and the Piper pilot was maneuvering; therefore, the Piper pilot was responsible for ensuring that the area was clear before initiating the inverted maneuver. Given the described geometry of the collision, the Piper pilot likely did not adequately clear for traffic before beginning the inverted flight maneuver, which he should have done, and failed to see the Cessna before impacting its left wing.

Verbatim NTSB analysis and probable cause from the NTSB dataset