The Most Important Step in our Emergency Procedures
In the first post I presented the two most important sentences in our flight manual, “The most important single consideration is helicopter control. All procedures are subordinate to this requirement.”
In the second post, I described IIMC or “lost visual cues” as the most critical emergency procedure based on its frequency and potential severity.
Accordingly, the most important steps in our emergency procedures are to “announce IIMC” (or “lost visual cues”) and “establish an instrument scan.”
Because we often operate in a flight regime that is low (near obstacles and terrain/water) and slow (on the backside of the power curve – where there is less autopilot functionality, power requirements are high, rates of descent increase rapidly, and the aircraft is susceptible to yaw), it is imperative that we practice our basic instrument scan on the backside of the power curve as well (not necessarily low to the water, terrain, or obstacles – in fact, I encourage you to mitigate the drill with some altitude to increase safety margins in the event of a power loss). Throughout my career, I have donned a vision limiting device (hood), turned off the autopilot/AFCS (to require an accelerated scan) and practiced transitioning between a hover, or air taxi, and forward flight using the instruments. This simple and efficient drill provides invaluable training.
Early in my career Dan Able, a former Air Station Commanding Officer, made the statement, “if you are a Coast Guard Aviator and you’ve never experienced IIMC (lost visual cues), stand by you will.” This remark was made after one of his crews was surprised by IIMC while prosecuting a SAR case in fog, over water, in the dark, early morning hours. I was one of the aviators who spelled the crew after the event. The rescue swimmer said the recovery was so low that rotor wash entered the cabin as the helicopter recovered from an unintentional descent. I have repeated Dan Able’s comment to many other young aviators. If you remain proficient in a low and slow basic instrument scan, it may save your crew’s life.
