EASA AD US-2026-13-51: Power Plant - Engine Mount System - Inspection

What to do

Operators of Gulfstream GVIII-G700 and GVIII-G800 airplanes must perform the required inspections and any necessary corrective actions before further flight, as specified in the Gulfstream Alert Customer Bulletins dated June 16, 2026. No special flight permits are allowed, and any deviations from required steps must be approved via an Alternative Method of Compliance. Compliance is effective immediately upon receipt of the directive.

Summary

Emergency Airworthiness Directive FAA AD 2026-13-51 addresses a critical safety issue affecting Gulfstream Aerospace Corporation Model GVIII-G700 and GVIII-G800 airplanes. The directive focuses on inspecting the engine mount system, specifically the engine thrust strut mounts, due to reports of broken hollow pin caps caused by missing or displaced sleeve bushings. This condition risks structural failure of the engine mount system and possible in-flight engine separation.

What changed

FAA AD 2026-13-51 introduces an immediate inspection requirement for the upper surfaces of the engine mount at the forward and aft thrust strut mount interfaces on both left and right engines. It mandates verifying proper installation of sleeve bushings, nuts, washers, and cotter pins, and requires corrective actions before further flight if discrepancies are found. This is a new emergency directive rather than an amendment to existing regulations.

Why it matters

This directive is critical for aviation professionals because an improperly installed engine thrust strut can compromise the structural integrity of the engine mount system, potentially leading to engine separation and loss of airplane control. Operators, maintenance, and compliance teams must prioritize these inspections to ensure flight safety and regulatory compliance. Failure to comply could result in grounding of affected aircraft and increased operational risk.