Unsecured insulation blanket to blame for emergency descent on Geraldton-bound Qantas flight
An incorrectly installed insulation blanket was to blame for a Geraldton-bound Qantas plane dropping more than 15,000 feet in six minutes, causing oxygen masks to be activated and passengers to be terrified.
The Perth to Geraldton QantasLink Fokker 100 flight on August 10 last year was cruising at 26,000 feet when an excessive cabin altitude warning sounded, alerting the crew that something was wrong.
Oxygen masks were deployed and the pilot made an emergency descent to 9000 feet. The flight continued to Geraldton.
According to the Australian Transport Safety Bureau’s investigation, an engineering inspection found an insulation blanket had “migrated from its location”, becoming wedged in one of the pressurisation system’s two air outflow valves, which affected the aircraft’s ability to maintain cabin pressure.
An ATSB report concluded the insulation blanked had likely “not been properly secured to the aircraft‘s structure” during recent heavy maintenance.
On the aircraft, insulation blankets in the same area as outflow valves were able to dislodge and move if not correctly secured, ATSB acting director transport safety Vik Chaudhri said.
“The investigation found that while the aircraft manufacturer’s instructions detailed that during maintenance installation blankets could be removed ‘as necessary’, those instructions did not reference the insulation blanket installation procedure,” Mr Chaudhri said.
“This resulted in insulation blankets not being properly secured to the structure.”
After the incident, passengers told how startled they were by the mid-air emergency. One passenger sitting in the front row told the Geraldton Guardian the crew was to be commended.
“The crew did a fantastic job … The pilot asked if there were any questions,” he said in August.
“Everybody was quite impressed.”
Qantas subsidiary Network Aviation conducted a fleet-wide inspection of its Fokker 100 fleet in response to the incident, identifying a “number” of aircraft with incorrectly installed insulation blankets.
Virgin Australia and Alliance Airlines have since carried out their own inspections for incorrectly installed insulation blankets.
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