Piper J3C N10510 and Piper PA28 N9221D accident near Winter Haven, Florida

Probable cause

The failure of both flight crews to see and avoid each other while operating in the airport environment.

NTSB analysis

A float-equipped J3C was returning to its seaplane base for a water landing after a local flight. A PA-28 was performing power-off 180° landing maneuvers at an airport adjacent to the seaplane base. Shortly after the PA-28 pilot announced a left turn to the base leg over the airport common traffic advisory frequency (CTAF), the airplanes collided nearly head-on at 465 ft above ground level.

Postaccident examination of both airplanes revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.

The J3C was not equipped with a radio, nor was it required to be. With no radio in the J3C, neither they nor the crew in the PA-28 would have had any attentional cueing that would have alerted them to the other airplane. Neither airplane was equipped with avionics that would allow for an in-cockpit traffic display and only the PA-28 was equipped with ADS-B out.

Review of video evidence from a nearby residence revealed that, given the two flight paths and the nearly head-on impact, the front-seat pilot of the J3C and the right-seat flight instructor of the PA-28 should have been able to detect the other airplane. Both crews efforts to detect the other likely would have been made more difficult by the complex background of sky and ground.

The PA-28 flight instructor’s postaccident toxicology testing results indicated that she had used the antihistamine medication cetirizine. Based on the cetirizine levels measured in cavity blood and tissue, it is possible that she may have been experiencing some associated sedation at the time of the accident. Although sedation can adversely affect vigilance, there is no clear evidence that this was a factor in the collision, which plausibly could have occurred in the absence of impairment.

Ethanol was detected at a very low level in a postmortem cavity blood specimen from the PA-28 pilot receiving instruction. Ethanol was not detected in his urine. These results indicate that some or all of the detected ethanol may have been from postmortem production, and that ethanol effects did not likely contribute to the accident.

The J3C was not equipped with a radio, nor was it required to be, and was therefore not self-announcing or able to receive transmissions on CTAF. With no radio in the JC3, neither they nor the crew in the PA-28 would have had any attentional cueing that would have alerted them to the other airplane. Neither airplane was equipped with avionics that would allow for an in-cockpit traffic display and only the PA-28 was equipped with ADS-B out. Had both flight crews had access to two-way radios and in-cockpit traffic displays, with ADS-B in and out, they likely would have been better able to see and avoid the impending collision.

Text from the NTSB. Open the NTSB docket for ERA23FA142 for the full record.