What happened
On 28 January 2005, a British Aerospace HS.748 Series 2A, registration G-BGMN, was performing a cargo flight from Ronaldsway Airport to East Midlands Airport. The aircraft had been loaded overnight at Ronaldsway by contracted staff. During the takeoff roll at East Midlands, the left over-wing emergency escape hatch detached from the fuselage.
While the crew initially believed the loss of pressurization was due to a known deferred defect in the aircraft's system, ground personnel later alerted the commander that the hatch was missing. Upon inspection, the crew found mail bags protruding from the empty hatch aperture. The hatch was eventually located near the runway at East Midlands Airport, showing significant damage to its lower corners.
The investigation
The AAIB investigation focused on the circumstances leading to the hatch's detachment. The investigation established that the aircraft was operating with a deferred technical defect regarding its pressurization system. Because the front access door was restricted to emergency use only, the crew had to use it to enter the aircraft, which was the only available access point for a fully loaded freighter.
Investigators examined the loading process at Ronaldsway, finding that the protective covers intended to prevent the accidental operation of the hatch handles were not properly secured. The investigation also reviewed the operator's safety management system, noting deficiencies in the training and oversight of contracted loading personnel at outstations.
Findings
- The primary cause of the incident was that protective covers for the hatch handles were not attached prior to loading.
- Movement of the cargo during the loading process likely caused the hatch handle to shift into the 'open' position.
- The lack of written loading instructions and inadequate training for ground staff contributed to the failure to secure the handles.
- The aircraft was operating with a deferred defect in the pressurization system, which led the crew to overlook the possibility of a structural failure during the initial climb.
- There were significant deficiencies in the operator's oversight and audit of contracted loading services at outstations.