What happened
On August 28, 2014, a Cessna C560XL, operated by Speedwings Executive Jet GmbH, departed from runway 23 at Geneva Airport. Shortly after the takeoff, the flight crew observed smoke appearing within both the cockpit and the passenger cabin. In response to the developing situation, the crew declared an emergency. Following a visual approach, the aircraft successfully returned to the airport and landed on runway 23 approximately six minutes after the initial departure.
The investigation
Investigators examined the aircraft to determine the source of the smoke. The inspection revealed local scorch marks on the carpeted floor, specifically located near an air conditioning duct outlet in the cabin. The investigation focused on the environmental control unit to identify why hot air had been released into the cabin area.
Findings
Technical analysis established that a faulty temperature switch within the environmental control unit was responsible for the incident. This malfunction caused hot air to be blown into the cockpit and cabin, which resulted in the emission of smoke. It was noted that a service bulletin regarding the replacement of this specific switch had been issued in December 2009.