When aircraft artisans at Corpus Christi Army Depot, Texas, recently identified a non-conforming honeycomb seal in a Black Hawk engine, it set in motion a series of events designed to keep the Army’s Black Hawk and Apache fleets safe from a potentially devastating mechanical failure.
Initial efforts to isolate the faulty component led U.S. Army Aviation and Missile Command aviation safety specialists to work with the Combat Capabilities Development Command Aviation & Missile Center (CCDC AvMC) to conduct a hazard assessment of the situation.
“Because of the potential for in-flight engine failure, members from AMCOM, AvMC and Program Executive Office-Aviation worked together to generate a Safety of Flight (SOF) message for the entire Army Aviation enterprise,” said Chief Warrant Officer 5 Mike Cavaco, AMCOM’s Aviation Branch Maintenance Officer.
Safety of Flight messages are high-priority notifications pertaining to any defect or hazardous condition of an Army-fielded system that can cause personal injury, death, or damage to the system. SOF messages can restrict specific performance capabilities, operational limits, or require immediate maintenance actions for a variety of reasons that could include material defect conditions. Depending on the severity of the defect, the entire fleet or a portion of the fleet could be grounded.
"When the non-conforming seal fails, other internal engine components overheat and will eventually fail, potentially resulting in a catastrophic event,” said CCDC AvMC senior engineer Keith Jones.
In the event that a safety message is issued requiring the grounding of aircraft, the already heavy maintenance workload increases due to the urgency of the situation. The process of crafting the safety message is important and involves collaboration between subject matter experts to ensure the maintainers receive a clear message. Those developing safety messages must also consider the additional maintenance burden is minimized in the field and the corrective action the maintainers take is effective in getting the fleet back to a high state of safety and readiness.
“The SOF message process averted at least one mishap this summer,” said Kevin Pulliam, Tech Chief, T700/T55 Product Office, Aviation Turbine Engines Project Office. Whether you write the SOF message or read the SOF message, these are some of the most important words you may touch in your career.”
In this case, a non-conforming seal assembly was identified and a message requiring immediate action was sent out to Army Aviation units. The SOF required the removal and disassembly of the suspect engines for visual inspection and repair (if needed) before the aircraft could be returned to flying status.
Because of this SOF, a number of suspect parts were found. According to Cavaco, although numerous engines had to be inspected, it was worth the effort to find the suspect seals.
By going through the clearly defined SOF message process in accordance with AR 750-6, Army Equipment Safety and Maintenance Notification, the hard work and effort expended across the Black Hawk and Apache maintenance crews to quickly comply with this SOF message averted what could have been a catastrophic event had an engine failed in flight.
“The emergency SOF message is a critical force protection measure to forestall a potential catastrophe. The SOF process is essential for continued airworthiness of Army aircraft." said CCDC AvMC’s Director for Airworthiness, Keith Darrow.
Whether a message is issued for information that may assist in system operation, a required special maintenance action to enable aircraft performance, or for an immediate intervention that could potentially save lives, the importance of communicating and executing through this process is clear. Feedback on how to improve the process is welcome. All comments related to improving the safety message process can be directed to the AMCOM Safety point of contact on any recently issued safety or maintenance message.