Loss of pressurization Serious incident Boeing 737-4Q3 JA8525,
ASN logo
ASN Wikibase Occurrence # 177428
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:Tuesday 30 June 2015
Type:Silhouette image of generic B734 model; specific model in this crash may look slightly different    
Boeing 737-4Q3
Owner/operator:Japan Transocean Air
Registration: JA8525
MSN: 26605/2752
Fatalities:Fatalities: 0 / Occupants: 37
Aircraft damage: Minor
Category:Serious incident
Location:55 km east-northeast of Tanegashima island, Kagoshima prefecture -   Japan
Phase: En route
Nature:Passenger - Scheduled
Departure airport:Okinawa-Naha Airport (OKA/ROAH)
Destination airport:Osaka-Kansai International Airport (KIX/RJBB)
Investigating agency: JTSB
Confidence Rating: Accident investigation report completed and information captured
Japan Transocean flight 002 from Naha-Okinawa to Kansai, a Boeing 737-4Q3, suffered cabin pressure problem. Both systems were inoperative. The flight crew dropped the cabin oxygen masks, and made a emergency descent from 11000 m (FL360) to 10000 ft. The plane continued to the destination, and a safe landing was carried out at KIX. No injury were reported.

It is highly probable that the serious incident occurred because the supply from the both Bleed Air systems were stopped, abnormal decompression was occurred in the cabin.
As for the stoppage of the both Bleed Air supply, it is highly probable that PRSOV was closed because the Bleed Air temperature was rising and exceeding the specified values in a state of occurrence of failures due to the cracks in the both systems of 450 ºF
Thermostat, and malfunctions were generated due to deteriorations at the both systems of Pre-cooler Control Valve

Accident investigation:
Investigating agency: JTSB
Report number: 
Status: Investigation completed
Duration: 2 years and 3 months
Download report: Final report



History of this aircraft

Other occurrences involving this aircraft
7 April 2015 JA8525 Japan Transocean Air 0 New Ishigaki Airport (ISG/ROIG) min
Bird strike

Revision history:

30-Jun-2015 14:07 isamuel Added
04-Aug-2023 17:17 harro Updated

Corrections or additions? ... Edit this accident description

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314