Taiwan’s Aviation Safety Council recommends enhanced training and record-keeping enforcement after concluding that improper maintenance precipitated a 2016 incident on China Airlines Flight 25.
The independent investigation organization found that abnormal cabin pressure prompted the Boeing 737-800 flight crew to make an emergency descent back to Guam shortly after takeoff. It was subsequently discovered that a broken gear pin rendered the outflow valve inoperable, an anomaly that went unnoticed because maintenance personnel were not adequately familiar with proper troubleshooting procedures. Logbook entry audits revealed that “many troubleshooting operations in the Technical Log Book were [conducted] according to the Aircraft Maintenance Manual rather than the recommended procedures consistent with the Fault Isolation Manual.”
In its report, the council recommended that transport category operators enhance Fault Isolation Manual training, and ensure that inspection teams review records for appropriate references.