The U.S. Federal Aviation Administration (FAA) has issued a Special Airworthiness Information Bulletin (SAIB) relating to certain converted cargo versions of the Boeing 757-200. This recommendation follows an incident in 2021 in which the main cargo door of a DHL Boeing 757 Freighter opened in flight.
On February 13, 2021, a DHL Boeing 757-200 PCF (Precision Conversions Freighter) took off from Leipzig/Halle Airport at 05:31 a.m. local time, bound for Frankfurt. Shortly after takeoff, at an altitude of about 1.530 meters, the crew encountered problems with the pressurized cabin and decided to return to the departure airport. After a safe landing, it was discovered that the front cargo door had opened during the climb. DHL later confirmed that "light parts of the cargo door frame" were torn off during the flight. The aircraft in question, originally delivered as a passenger aircraft in 1992 and converted to a freighter in 2011, was taken out of service after the incident.
Similar incidents in the past
A similar incident occurred in Russia in 2014. A Boeing 757-200 PCF operated by Yakutia Airlines took off from Magadan in extremely cold temperatures of up to -25 degrees Celsius. After takeoff, the cargo door opened due to icing on the locking mechanisms, which led to a drop in cabin pressure. The plane returned safely to the departure airport. Investigations revealed that snow and ice had prevented the door sensors from functioning properly.
The conversion of Boeing 757-200 passenger aircraft to cargo aircraft includes the installation of a hydraulically operated main cargo door and mechanical locks to secure the door during flight. In addition, proximity sensors are installed to indicate to the crew whether the door is correctly closed and locked. These sensors are designed to ensure that the door is properly secured before takeoff.
FAA recommendations
In the bulletin published on February 21, 2025, the FAA recommends that operators of the affected aircraft perform specific inspection and maintenance on the main cargo door every 5.000 flight cycles. Recommended actions include:
- Cleaning the viewing windows and mirrors: Removal of dirt, debris and other contaminants that may impair visibility of the locking mechanisms.
- Checking the locks and locking pins: Ensure that there is no paint damage or wear that could indicate mechanical problems.
- carrying out functional tests: Checking the door in the “open”, “closed” and “locked and secured” states to ensure correct functionality.
The FAA places particular emphasis on cold weather operations. It recommends removing ice and snow from around the cargo door and its mechanisms and performing additional inspections after exposure to freezing fog or icing conditions. These precautions are designed to prevent icing from interfering with the proper operation of the locking mechanisms.
Historical Perspective on Cargo Door Incidents
There have been several serious accidents related to cargo doors in the history of aviation. A tragic example is the crash of a Turkish Airlines McDonnell Douglas DC-10 in 1974 near Paris. After takeoff, the cargo door opened, causing an explosive depressurization and causing the aircraft to crash, killing all 346 passengers. Another incident occurred on United Airlines Flight 1989 in 811, when the forward cargo door of a Boeing 747 opened during climb. The resulting depressurization resulted in the loss of nine passengers who were sucked out of the aircraft. These events underscore the critical importance of proper maintenance and inspection of cargo doors.
reactions of the industry
The release of the FAA bulletin has generated mixed reactions in the aviation industry. While some operators welcome the recommendations as a necessary precautionary measure, others have expressed concerns about the additional maintenance effort and associated costs. Some airlines have already begun adjusting their maintenance protocols accordingly to comply with the FAA's recommendations and ensure the safety of their fleets.
The FAA emphasizes that the bulletin is a recommendation and not a mandatory directive. Nevertheless, many operators are expected to implement the suggested measures to minimize the risk of similar incidents in the future. Continuous inspection and maintenance of safety-critical components remains a key aspect of cargo aircraft operations, especially older models such as the Boeing 757-200.