Overview
• Operator: Biman Bangladesh Airlines
• Aircraft Model: Boeing 737-800
• Registration: S2-AFM
• Flight Number: BG-388
• Route: Dhaka (DAC) → Bangkok (BKK)
• Date: 28 February 2025
• Occupants: Not specified
• Casualties: None
• Nature of Incident: Cabin pressurization failure, emergency descent, return to Dhaka
Incident Summary
A Biman Bangladesh Boeing 737-800 operating flight BG-388 from Dhaka to Bangkok experienced a cabin pressurization failure during the climb.
The aircraft had reached FL250 when the crew identified an issue with cabin pressurization.
The passenger oxygen masks deployed, prompting the crew to initiate an emergency descent to FL100.
The crew decided to return to Dhaka, where the aircraft landed safely approximately 110 minutes after departure.
Sequence of Events
Pre-Incident Conditions:
• The aircraft departed from Dhaka normally.
• No pressurization issues were reported during pre-flight checks.
Incident During Climb:
• While climbing through FL250, the crew identified a cabin pressurization issue.
• Passenger oxygen masks deployed as the cabin altitude exceeded safety limits.
• The crew stopped the climb and immediately descended the aircraft to FL100.
Decision to Return:
• The aircraft was flying over Myanmar at the time of the incident.
• The crew coordinated with ATC to return to Dhaka rather than continuing to Bangkok.
• The aircraft landed safely at Dhaka approximately 110 minutes after departure.
Aftermath:
• Passengers were rebooked onto other flights to Bangkok.
• Engineers began an inspection to determine the cause of the pressurization failure.
• No injuries were reported among passengers or crew.
Investigation & Findings
Possible Causes of the Incident:
While the official cause is still under investigation, potential factors include:
1. Faulty Cabin Pressure Controller: Malfunction in the aircraft’s automatic pressurization system.
2. Outflow Valve Malfunction: A failure in the valves controlling cabin pressure.
3. Leak in the Pressurization System: Structural issues causing an inability to maintain cabin pressure.
4. Sensor Failure: Incorrect data being fed to the pressurization system, causing it to malfunction.
Impact of the Incident:
• No injuries reported.
• Potential mechanical issues requiring further investigation.
• Flight disruption, requiring rebooking of passengers.
• Investigation by Biman Bangladesh Airlines and aviation authorities.
Analysis & Safety Recommendations
For Airlines & Flight Crews:
• Enhanced monitoring of cabin pressurization systems during climb.
• Review of maintenance records to check for any past pressurization-related anomalies.
• Cabin crew training for emergency descent scenarios to ensure efficient mask deployment and passenger safety.
For Airports & Aviation Authorities:
• Investigation into maintenance and service logs for the affected aircraft.
• Implementation of additional pressurization system checks before departure.
• ATC coordination for emergency descents and diversion procedures.
Conclusion
This incident highlights the critical importance of aircraft pressurization systems and rapid crew response in emergencies.
The Biman Bangladesh crew handled the situation efficiently, ensuring the safety of passengers and crew by descending to FL100 and returning to Dhaka.
An investigation is ongoing to determine the root cause, which will inform future safety measures.
Disclaimer
“This report is based on available information as of 4 March 2025. While every effort has been made to ensure accuracy, the completeness of the details cannot be guaranteed. If you are the rightful owner of any referenced materials and wish them removed, please email takedown@cockpitking.com.”
