The crew of a Cessna Citation X (VH-RCA) has been praised by the Australian Transport Safety Bureau for dealing well with a windshield crack at very high altitude.
The just-published ATSB report on the 15 January incident records that the aircraft, carrying two pilots and five passengers, had just levelled at 45,000ft (13,700m) about 90min after take-off from Faleolo airport, Samoa, bound for Sydney, Australia, when the "windscreen heat inoperative" warning came on, and 2min later, the outer ply fractured with a loud bang. The crew switched off the windscreen heating switches and carried out the emergency depressurisation drill, donning oxygen masks and deploying cabin oxygen, and began an emergency descent while turning toward Nadi, Fiji, and issuing a mayday call.
During the descent the pilot monitoring briefed the passengers and prepared them for a possible ditching. There was no actual depressurisation, and the crew levelled the aircraft at 14,000ft and downgraded the emergency to a pan call.
The aircraft landed safely at Nadi with no injuries resulting from the incident.
On 26 January the aircraft was ferried to Sydney, where examination of the windscreen by the ATSB showed there had been water ingress at the top of the screen which had affected a soldered electrical joint connecting the electrical busbar to the windscreen heating film. This had degraded, damaging the connection, allowing short-circuiting and a heat build-up, and creating thermal stress on the screen. The ATSB notes that this fault had been detected before and was subsequently dealt with by a manufacturer's modification that has been made available.
The ATSB praised the crew for preparing for a depressurisation although one did not actually take place, and for making a timely diversion.