The Federal Aviation Administration (FAA) has identified a potential safety issue involving ram air turbine (RAT) forward fittings on certain Boeing 787-9 and 787-10 aircraft. The agency received reports from multiple suppliers indicating that some RAT forward fittings may have been manufactured with substandard titanium.
According to the FAA, the titanium in question could be Grade 1 or 2 commercially pure unalloyed titanium, which does not meet the strength, fatigue, and damage tolerance requirements of aerospace-grade Grade 5 Ti-gAI-4V alloy. The FAA warned that if these parts are not addressed, they could fail when the RAT is deployed, possibly resulting in loss of backup hydraulic and electric power for the aircraft.
In a statement included in its proposed directive, the FAA said: “A proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-9 and 787-10 airplanes. This proposed AD was prompted by reports of multiple supplier notices of escapement (NOEs) indicating that ram air turbine (RAT) forward fittings were possibly manufactured with an incorrect titanium alloy material.”