EASA Issues Warning on Malfunctioning Doors of Converted Boeing 757 Freighters
The European Union Aviation Safety Agency (EASA) has issued a warning urging operators of certain Boeing 757 freighter conversions to ensure compliance with two service bulletins, emphasizing the importance of verifying that cargo doors are securely latched before takeoff to prevent potential in-flight openings.
In a safety information bulletin (SIB) released on June 23, EASA references two incidents where main cargo doors opened during flight. The most recent occurrence involved a DHL-operated 757 in February 2021, when the main door unexpectedly opened during climb-out from Leipzig/Halle Airport in Germany. The crew promptly declared an emergency and safely returned to the airport.
A preliminary investigation by Germany’s Federal Bureau of Aircraft Accident Investigation (BFU) revealed that the hinges connecting the door to the fuselage were not locked prior to departure. The ongoing probe is examining two potential causes: a hydraulic system malfunction that impeded proper door closure, or ice contamination affecting sensors responsible for indicating whether the door is securely locked. BFU mentioned a similar scenario that transpired in Russia in 2014 during severe winter weather, but no further details or investigation updates were provided.
EASA’s bulletin specifically pertains to Boeing 757-200s that underwent conversion from passenger to freighter configuration under EASA Supplemental Type Certificate (STC) 10015539 issued in 2014. The bulletin highlights two service bulletins released by STC holder Precision Conversions. One, issued in July 2006, outlines modifications to the collective locking system, while the other, released in October 2022, covers changes to the door indication system.
Affected operators are urged to ensure that the design improvements described in the service bulletins have been implemented on their aircraft. If not already done, the changes should be promptly implemented. EASA also emphasizes the importance of maintaining the view ports used to verify closed latches in good condition, without any scratches or significant defects. Additionally, aids such as a color-contrasted lock pin tip and functioning mirrors for viewing latches inside the closed door should be in proper working order.
BFU’s report does not provide specific details regarding pre-flight activities related to door closure. Following the incident, DHL issued safety actions for its fleet of 757-236 converted freighter aircraft. These actions require crews to visually inspect latches from outside through the eight ports and ensure proper locking and positioning of the locking pins. Flight crews are advised to closely monitor cargo door indications before flight to ensure complete closure and secure locking.
Sources: AirGuide Business airguide.info, aviationweek.com, boeing.com