Accident Overview
A midair collision occurred less than one mile northwest of the approach end of runway 14 during a VOR/DME approach. The airplanes involved were a Merlin and an AA-5A. Both aircraft were operating in conditions of low ceiling and fog, as reported by a pilot weather report (pirep) of 500 feet over the field with two miles visibility and 'zilch' over the water.
Sequence of Events
Prior to the final approach fix (FAF) on the VOR/DME approach, the Merlin was cleared by air traffic control to change to the unicom frequency. The pilot of the Merlin contacted unicom and requested an airport advisory. The unicom operator provided the pirep information. Shortly after this exchange, the pilot of the AA-5A called on unicom, turning final. The unicom operator relayed the same advisory to the AA-5A pilot and further advised that another aircraft was inbound for runway 14. The collision occurred after these communications.
Communication Practices
The Aeronautical Information Manual (AIM) contains recommendations for radio communications in such scenarios. AIM paragraph 157 recommends that VFR inbound flights broadcast when entering downwind and final. AIM paragraph 363 recommends that, when making an IFR approach to an airport not served by a control tower or flight service station, and after ATC advises to change to the advisory frequency, pilots should broadcast their intentions, including the type of approach, position, and when over the FAF inbound.
Findings
The official investigation reported the probable cause as a midair collision during an IFR circling approach due to inadequate visual lookout by both flight crews. Additional findings include unavailable control tower, unavailable radar approach/departure, low ceiling, fog, and inadequate air/ground communications from both crews.
Occupants and Damage
All three occupants in each airplane—six total—were killed in the collision. The source does not specify the registration, operator, or exact date and time of the accident.