What happened
On a scheduled domestic flight traveling from Pittsburgh to Dayton, TWA Flight 553 was operating under IFR flight rules and radar surveillance. As the DC-9 approached the Dayton terminal area, air traffic controllers transferred radar control from Indianapolis ARTCC to Dayton RAPCON. During the descent process, the controller instructed the crew to descend to 3,000 feet and turn to a heading of 230 degrees. Shortly after this instruction was acknowledged, the controller identified an unidentified radar target ahead of the flight and issued a traffic advisory regarding a slow-moving aircraft at the 12 o'clock position.
Fourteen seconds following the advisory, the radar signatures of the two aircraft merged and subsequently disappeared from the screen. The second aircraft involved was a Beechcraft Baron B-55 operating as a business flight from Detroit to Springfield, Ohio. This aircraft had departed Detroit City Airport under special VFR conditions without a filed flight plan. While the pilot of the Beechcraft had previously communicated with his company regarding an upcoming landing, no further air traffic control contact was recorded for this aircraft.
The collision occurred at 11:53:50 hours at an altitude of approximately 4,525 feet, roughly 25 nautical miles northeast of Dayton Municipal Airport. The impact caused both aircraft to crash, with the wreckage of the commercial jet located in a nearby wooded area. The accident resulted in 26 fatalities, representing all occupants aboard both aircraft.
Findings
Investigation into the accident determined that the primary cause was the failure of the crew operating the DC-9 to visually identify and avoid the Beechcraft Baron B-55. Several contributing factors were identified, including environmental and physiological conditions affecting visibility. Additionally, the high speed of the commercial aircraft limited the crew's ability to detect the other plane. The investigation also noted that the existing air traffic control system was not equipped to manage the separation of controlled and uncontrolled flight traffic effectively.