A Saab 340 turboprop airliner was unable to pressurise due to two sections of broken door seal, which were misidentified by flight crews as cosmetic damage, an Australian Transport Safety Bureau investigation has found.
On 25 March 2023, the Link Airways operated Saab 340B took off from Canberra Airport for a scheduled passenger flight to Sydney.
During the climb, the flight crew noticed a higher than normal cabin altitude of 6,500 ft.
In response, they descended the aircraft, and remained below 10,000 ft for the remainder of the flight, and landed without incident at Sydney.
“The ATSB found two sections of broken door seal seat meant the aircraft’s pressurisation system was not able to maintain normal cabin altitude in flight,” ATSB Director Transport Safety Stuart Macleod explained.
“One broken section was found after the last flight the day before, but it was incorrectly assessed as a piece of cosmetic trim by the off-going flight crew, and reported as such to the maintenance organisation and a licenced aircraft maintenance engineer.”
The morning of the incident, the on-coming flight crew noted an additional section of broken door seal seat, but misidentified it as the previously reported cosmetic defect, and the aircraft was assessed as serviceable for flight.
“Communication between aircrew and maintenance engineers is critical to the continuing airworthiness of aircraft,” Mr Macleod said.
“Follow-up questioning, demonstration, or the use of photos or video should be employed to ensure accurate and effective communication.
“In addition, when recording defects or rectifications in aircraft technical logs, to minimise ambiguity aircrew and maintenance engineers should include as much detail as practical.”
Read the report: Cabin pressurisation fault, Saab 340B, VH-VEZ, 20 km south-west of Goulburn, New South Wales on 25 March 2023