G3, Investigations, Reporting and Tracking
U.S. Army Combat Readiness Center
Fort Rucker, Alabama
Looking back on two recent non-combat, rotary-wing, fatal aviation mishaps reveals several commonalities. Primarily, there was no emergency that should have precluded the flight crews from executing, at a minimum, safe precautionary landings. Having said that, had either flight crew reacted to the actual emergency procedure (EP) as presently written, they both could have — and should have — been able to execute a single-engine landing as soon as practicable.
A UH-60L flight crew was executing a real-world MEDEVAC mission effectively at sea level when one of the aircraft engines experienced an internal component failure. This put the crew in a single-engine failure response scenario. After identifying that there was a single-engine emergency, the flight crew incorrectly executed the EP for the appropriate engine failure. While the aircraft was on the bottom side of the single-engine flight envelope, it was still flyable. Had the crew executed the proper response to the single-engine failure, they could have made a precautionary landing or returned to base and performed a roll-on landing. Either way, the mission was probably not going to be accomplished, but the fatal mishap would not have occurred either.
This mishap highlighted improper identification and crew interaction to an actual EP. It led the aviation community to take an internal look at the methodology and response to an EP as well as the initial and sustainment training of EPs. Expect changes to the identification, reaction and response to EPs from the currently taught and evaluated method.
A UH-60L crew was executing a limited maintenance test flight (LMTF) for a component replacement and verification. To verify the aircraft’s airworthiness, the LMTF required the maintenance test pilot (MTP) to manipulate the power control lever (PCL) for the engine not being checked; the purpose of this was to place a greater load on the engine actually being checked. The MTP set up this maintenance task to standard and provided the flying pilot with the appropriate maneuver, abort criteria, limitation, emergency (MALE) briefing prior to initiating the action.
As the MTP retarded the No. 2 PCL, his attention was focused primarily inside the aircraft, monitoring the engine instruments. During the second portion of the maintenance task, the crew received an actual No. 1 engine failure indication. The engine experienced an external component failure, putting the flight crew in a single-engine failure scenario. Unlike the mishap above, this crew experienced their engine failure when their non-failed engine, the No. 2 engine, PCL was at or near idle. Their immediate action steps prior to responding to the single-engine failure were addressed in the MALE brief. However, the flight crew executed those steps incorrectly, which ultimately resulted in a rapid decay of the aircraft rotor system and an extreme rate of decent.
Following the actual failure of the No. 1 engine, the aircraft was still in a flyable condition. Had the crew responded appropriately to the engine failure by following the MALE briefing and recovering from the maintenance task, the aircraft would have been able to maintain single-engine flight. This means continued flight was possible and the aircrew would have been able to return to home station, where they could have executed a roll-on landing.
After reading both of these mishap scenarios, do you know how you would respond to an actual EP? If you have never experienced a single-engine failure in a dual-engine aircraft, do you really know? Then ask yourself this: How would your co-pilot respond? You may know how you would want them to react, but it’s impossible to say for sure until you are in that position. Both of these flight crews departed their home stations to execute missions for which they were fully qualified to conduct. When an emergency presented itself, their responses are what ultimately resulted in four fatalities, several significant injuries and the loss of two flyable aircraft.
Remember that being a professional requires you to know your duties and responsibilities as the flying and non-flying pilot. Emergencies generally do not give you an indication they are about to occur. Proper identification and response is critical. Sometimes this response requires immediate action steps and other times it does not. Be professional and ask yourself how you will respond.