The Federal Aviation Administration (FAA) has issued a new airworthiness directive (AD) targeting specific Gulfstream Aerospace Corporation models, the GVII-G500 and GVII-G600. This regulatory measure stems from a critical safety concern raised after the discovery of a failed rear engine mount on one of these aircraft during a preflight inspection. The malfunction, notably visible as engine misalignment, necessitates immediate attention.
According to the FAA, the directive mandates rigorous inspections of the engine mount points located within the pylons and engine nacelles to identify any “non-conforming hardware installation.” The checks are crucial to ensure that all components adhere to safety standards and to facilitate any necessary repairs. Moreover, the aircraft maintenance manual (AMM) is to be updated to integrate revised procedures for engine removal and installation, aiming to prevent future occurrences of such safety risks.
The issue first came to light on January 31, 2024, when a Model GVII-G600 exhibited a partially disengaged rear engine mount, spotted due to misalignment near the pylon area adjacent to the thrust reverser. Detailed examination revealed that the upper, aft engine mount fastener had nearly dislodged, attributed to the absence of a vital secondary locking device—a “cotter pin”—which resulted in the retaining nut separating from the strut attachment bolt.
Further investigation revealed this oversight occurred during a post-production engine change, where the cotter pin was not installed, and the securing hardware was improperly fastened. This lapse was linked to maintenance personnel not adhering strictly to the AMM procedures and not consulting with production engine installation experts as required.
Subsequent evaluations by Gulfstream uncovered more instances of non-conforming engine mount installations across other aircraft. While these were not deemed critical, they underscored ongoing issues with quality control in both production and maintenance processes. These findings have prompted a reevaluation of existing procedures and highlighted the need for stricter adherence to established guidelines.
The FAA has identified discrepancies in both the production processes and the AMM, particularly concerning missing hardware details and inconsistent graphics that could lead to misinterpretations during maintenance operations. The directive, which impacts 247 registered aircraft in the U.S., underscores the FAA’s commitment to maintaining rigorous safety standards and addressing potential vulnerabilities before they compromise safety.