Inadvertent Instrument Meteorological Conditions (IIMC) leading to pilot spatial disorientation continue to be a leading cause of fatal helicopter accidents. From 2000 to 2019 in the US, there were 130 fatal accidents directly linked to the issue of spatial disorientation. These accidents occurred regardless of pilot experience and they cut across all industries, including emergency medical services, law enforcement, tour operations, utility flights, corporate flying and personal / private flights.
“For decades, studies, articles, research papers, and discussions have been published theorizing why accidents related to degraded visual environments consistently occur and it has been hard to find clear answers that can slow or stop these tragic accidents,” explained Nick Mayhew, industry Co-Chair of the USHST. “In part, the accidents stem from failed planning, lack of understanding, or poor decision-making. All pilots have the option to turn down a flight before launch, turn around, proceed to an alternate, or land in a safe place if the weather deteriorates below company or personal minimums, yet we continue to see these types of accidents.”
The Recommended Practices document focuses on training and decision-making actions:
- Avoidance of IIMC
- Pre-flight planning that includes en route decision processes
- In-aircraft training that simulates a lack of visibility
- Training of recovery techniques and committing to instruments
Avoidance of IIMC
Avoidance is the best defense. There are several tools at a pilot’s disposal to ensure they put themselves, the crew, and the safety of their passengers in the best position for a successful flight. Often, that may be opting to delay or cancel the launch based on conditions present or anticipated during the flight. These decisions can be difficult to make, but when a pilot conducts a thorough pre-flight analysis, the preponderance of evidence can make that risk management decision straightforward and data-based.
Training of Recovery Techniques and Committing to Instruments
The best techniques for survival of spatial disorientation encounters is to avoid them. However, with proper training, pilots can be more successful in trusting instruments. For pilots to trust their instruments, they have to train the brain to disregard the vestibular illusions experienced during spatial disorientation. This is accomplished by simultaneously exposing a pilot to visual and vestibular illusions in training. This exposure will provide the brain the training it requires to function in ‘fast brain’ and successfully disregard the conflicting illusions and focus on the instruments.
More information about the USHST, the International Helicopter Safety Foundation, its reports, safety tools, Reel Safety audio-visual presentations, and YouTube safety videos can be obtained on the USHST website and on its Facebook pages.