ATSB TRANSPORT SAFETY REPORT
Aviation Occurrence Investigation AO-2008-053
Preliminary
Depressurisation
475 km north-west of Manila, Philippines
25 July 2008
Boeing Company 747-438, VH-OJK
Published by: Australian Transport Safety Bureau
Postal address: PO Box 967, Civic Square ACT 2608
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© Commonwealth of Australia 2008.
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ISBN and formal report title: see ‘Document retrieval information’ on page v.
DOCUMENT RETRIEVAL INFORMATION
Report No.
AO-2008-053
Publication date
August 2008
No. of pages
38
ISBN
978-1-921490-65-1
Publication title
Depressurisation, 475 km North-West of Manila, Philippines
Boeing Company 747-438, VH-OJK
Prepared by
Australian Transport Safety Bureau
PO Box 967, Civic Square ACT 2608 Australia
www.atsb.gov.au
Reference No.
INFRA - 08244
Acknowledgements
The diagrams presented within Attachments A and B of this report were provided courtesy of the Boeing Company.
Abstract
On 25 July 2008, at 0922 local time, a Boeing Company 747-438 aircraft (registered VH-OJK)
with 365 persons on board, departed Hong Kong International airport on a scheduled passenger
transport flight to Melbourne, Australia. Approximately 55 minutes into the flight, while the
aircraft was cruising at 29,000 ft (FL290), a loud bang was heard by passengers and crew,
followed by the rapid depressurisation of the cabin. Oxygen masks dropped from the overhead
compartments shortly afterward, and it was reported that most passengers and crew commenced using the masks. After donning their own oxygen masks, the flight crew carried out the ‘cabin altitude non-normal’ checklist items and commenced a descent to a lower altitude, where supplemental breathing oxygen would no longer be required. A MAYDAY distress radio call was made on the regional air traffic control frequency. After levelling the aircraft at 10,000 ft, the flight crew diverted to Ninoy Aquino International Airport, Manila, where an uneventful visual approach and landing was made. The aircraft was stopped on the runway for an external
inspection, before being towed to the terminal for passenger disembarkation.
Subsequent inspection of the aircraft by the operator’s personnel and ATSB investigators,
revealed an inverted T-shaped rupture in the lower right side of the fuselage, immediately beneath the wing leading edge-to-fuselage transition fairing (which had been lost during the event). Items of wrapped cargo were observed partially protruding from the rupture, which extended for approximately 2 metres along the length of the aircraft and 1.5 metres vertically.
After clearing the baggage and cargo from the forward aircraft hold, it was evident that one
passenger oxygen cylinder (number-4 from a bank of seven cylinders along the right side of the
cargo hold) had sustained a sudden failure and forceful discharge of its pressurised contents into
the aircraft hold, rupturing the fuselage in the vicinity of the wing-fuselage leading edge fairing.
The cylinder had been propelled upward by the force of the discharge, puncturing the cabin floor
and entering the cabin adjacent to the second main cabin door. The cylinder had subsequently
impacted the door frame, door handle and overhead panelling, before falling to the cabin floor and exiting the aircraft through the ruptured fuselage.
The investigation is continuing.
THE AUSTRALIAN TRANSPORT SAFETY BUREAU
The Australian Transport Safety Bureau (ATSB) is an operationally independent
multi-modal bureau within the Australian Government Department of
Infrastructure, Transport, Regional Development and Local Government. ATSB
investigations are independent of regulatory, operator or other external
organisations.
The ATSB is responsible for investigating accidents and other transport safety
matters involving civil aviation, marine and rail operations in Australia that fall within Commonwealth jurisdiction, as well as participating in overseas investigations involving Australian registered aircraft and ships. A primary concern is the safety of commercial transport, with particular regard to fare-paying passenger operations.
The ATSB performs its functions in accordance with the provisions of the Transport Safety Investigation Act 2003 and Regulations and, where applicable, relevant international agreements.
Purpose of safety investigations The object of a safety investigation is to enhance safety. To reduce safety-related risk, ATSB investigations determine and communicate the safety factors related to the transport safety matter being investigated.
It is not the object of an investigation to determine blame or liability. However, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner.
Developing safety action Central to the ATSB’s investigation of transport safety matters is the early identification of safety issues in the transport environment. The ATSB prefers to
encourage the relevant organisation(s) to proactively initiate safety action rather than release formal recommendations. However, depending on the level of risk associated with a safety issue and the extent of corrective action undertaken by the relevant organisation, a recommendation may be issued either during or at the end of an investigation.
The ATSB has decided that when safety recommendations are issued, they will focus on clearly describing the safety issue of concern, rather than providing instructions or opinions on the method of corrective action. As with equivalent overseas organisations, the ATSB has no power to implement its recommendations.
It is a matter for the body to which an ATSB recommendation is directed (for example the relevant regulator in consultation with industry) to assess the costs and benefits of any particular means of addressing a safety issue.
About ATSB investigation reports: How investigation reports are organised and definitions of terms used in ATSB reports, such as safety factor, contributing safety factor and safety issue, are provided on the ATSB web site www.atsb.gov.au.
1
FACTUAL INFORMATION
The information contained in this preliminary report is derived from the initial investigation of the occurrence. Readers are cautioned that there is the possibility that new evidence may become available that alters the circumstances as depicted in the report.
The information contained in this preliminary report is derived from the initial investigation of the occurrence. Readers are cautioned that there is the possibility that new evidence may become available that alters the circumstances as depicted in the report.
History of the flight
At 0922 local time (0122 UTC1) on 25 July 2008, a Boeing 747-438 aircraft, registered VH-OJK, departed Hong Kong International Airport on a scheduled passenger transport service to Melbourne, Australia. On board the aircraft (operating as flight number QF30) were 346 passengers (including four infants), 16 cabin crew and three flight crew (captain, first officer and second officer).
The flight crew reported that the departure and climb-out from Hong Kong was normal, with the aircraft established at the assigned cruising altitude of 29,000 ft (FL290) by 0942 (0142 UTC).
At 1017 (0217 UTC), the captain and first officer reported hearing a ‘loud bang or cracking sound’ with an associated airframe jolt. At that time, the autopilot disconnected, and the first officer, who was the pilot flying at the time, assumed manual control of the aircraft. Multiple EICAS2 messages were displayed, including warnings regarding the R2 door status and cabin altitude.3 The second officer, who was in the forward crew rest position, returned to the first observer’s crew seat and all flight crew donned oxygen masks before completing the ‘cabin altitude nonnormal’ checklist. At that time, the aircraft was approximately 475 km to the northwest of Manila, Philippines.
The cabin crew reported that shortly after the bang was heard, oxygen masks fell from most of the personal service units in the ceiling above passenger seats and in the toilets. Most passengers started using the oxygen masks soon after they dropped. All cabin crew, who were engaged in passenger service activities at the time, immediately located oxygen masks to use. Some crew located a spare passenger mask and sat in between passengers, while others went to a crew jumpseat at an exit, and one used a mask in a toilet.
Approximately 20 seconds after the event, the captain reduced the thrust on all four engines and extended the speed brakes. The first officer commenced the descent while the captain declared a MAYDAY4 on the Manila flight information region (FIR) radio frequency.
At 1024 (0224 UTC), the aircraft reached, and was levelled at an altitude of 10,000 ft, where the use of supplementary oxygen by passengers and crew was no longer required.
1 Universal Time, Coordinated (previously Greenwich Mean Time, GMT).
2 Engine Indication and Crew Alerting System.
3 The altitude corresponding to the air pressure inside the aircraft cabin.
4 International call for urgent assistance.
At 1017 (0217 UTC), the captain and first officer reported hearing a ‘loud bang or cracking sound’ with an associated airframe jolt. At that time, the autopilot disconnected, and the first officer, who was the pilot flying at the time, assumed manual control of the aircraft. Multiple EICAS2 messages were displayed, including warnings regarding the R2 door status and cabin altitude.3 The second officer, who was in the forward crew rest position, returned to the first observer’s crew seat and all flight crew donned oxygen masks before completing the ‘cabin altitude nonnormal’ checklist. At that time, the aircraft was approximately 475 km to the northwest of Manila, Philippines.
The cabin crew reported that shortly after the bang was heard, oxygen masks fell from most of the personal service units in the ceiling above passenger seats and in the toilets. Most passengers started using the oxygen masks soon after they dropped. All cabin crew, who were engaged in passenger service activities at the time, immediately located oxygen masks to use. Some crew located a spare passenger mask and sat in between passengers, while others went to a crew jumpseat at an exit, and one used a mask in a toilet.
Approximately 20 seconds after the event, the captain reduced the thrust on all four engines and extended the speed brakes. The first officer commenced the descent while the captain declared a MAYDAY4 on the Manila flight information region (FIR) radio frequency.
At 1024 (0224 UTC), the aircraft reached, and was levelled at an altitude of 10,000 ft, where the use of supplementary oxygen by passengers and crew was no longer required.
1 Universal Time, Coordinated (previously Greenwich Mean Time, GMT).
2 Engine Indication and Crew Alerting System.
3 The altitude corresponding to the air pressure inside the aircraft cabin.
4 International call for urgent assistance.
EL TEXTO COMPLETO LO PODRAN BAJAR DE AQUI, ES BIEN LARGUITO...
GRACIAS EDUARDO POR LA GENTILEZA!!!
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