What happened
On the morning of the accident, Wings West Airlines Flight 628 was operating a scheduled commuter service from Los Angeles to San Francisco, with planned stops in Santa Maria and San Luis Obispo. At 11:10, the flight departed from the gate at San Luis Obispo under clear weather conditions with visibility reaching 15 miles. Shortly after departing runway 29, the crew contacted Los Angeles ARTCC at 11:16 to report a climb through 2,700 feet while operating under IFR toward San Francisco.
At 11:17:23, air traffic controllers cleared the aircraft to climb and maintain 7,000 feet. However, at 11:17:38, the aircraft collided head-on with a Rockwell Commander N112SM at an altitude of 3,400 feet. The second aircraft, N112SM, had departed from Paso Robles Airport as part of a training flight carrying two pilots. At the time of the impact, the single-engine plane was operating under VFR in the area near San Luis Obispo.
Findings
Investigations determined that the pilots of both aircraft failed to adhere to recommended communication and traffic advisory protocols outlined in the Airman’s Information Manual. Specifically, they did not utilize proper practices for uncontrolled airports to signal their presence or assist controllers in providing timely advisories. The failure to follow established communication and traffic advisory practices was a primary factor.
Other contributing elements included the inherent physiological constraints of human vision and reaction speed, as well as the limited window available for the controller to identify radar data and issue warnings. Additionally, an airline policy requiring pilots to keep one radio tuned to a company frequency at all times was noted as a contributing factor.