Helicopter pilot flying into IIMC can result in spatial disorientation
a/k/a somatogravic illusion
NTSB looks to simulator training to address
Industry provides one
This is the initial words of an NTSB announcing its findings as to the probable cause of Kobe Bryant’s helicopter tragic crash. The Board made the following findings as to the FAA:
“1.Require the use of appropriate simulation devices during initial and recurrent pilot training for Title 14 Code of Federal Regulations Part 135 helicopter operations to provide scenario-based training that addresses the decisionmaking, skills, and procedures needed to recognize and respond to changing weather conditions in flight, identify and apply mitigation strategies for avoiding adverse weather, practice the transition to the use of flight instruments to reduce the risk of spatial disorientation, and maintain awareness of a variety of influences that can adversely affect pilot decision-making.
- Convene a multidisciplinary panel of aircraft performance, human factors, and aircraft operations specialists to evaluate spatial disorientation simulation technologies to determine which applications are most effective for training pilots to recognize the onset of spatial disorientation and successfully mitigate it, and make public a report on the committee’s findings.”
The Report repeats prior recommendations that the FAA require that “ all existing turbine-powered, nonexperimental, nonrestricted-category aircraft that are not equipped with a flight data recorder or cockpit voice recorder.” Equipping these aircrafts with this equipment has been a subject of considerable regulatory and legislative debate. These prior blogs have discussed the relevant issues.
Chairman Robert Sumwalt ‘s presentation mentioned “the pilot’s spatial disorientation”, what is known in the technical literature as somatogravic illusion. It is a complex processing of stimuli to the pilot’s brain from the otolith organs (part of the vestibular apparatus), visual cues and aviation’s most relied upon (but not so reliable) sensor-the seat of the pants. Not all of those indicia of flight can be replicated in a multiple axis simulator.
Almost as though he was prescient, the Chairman’s call for such technology received almost immediate responses from the USHST and industry. The trade association announced a new set of recommended practices. Also AT Systems, in conjunction with the US Army, is developing a onboard visual simulation system. An instructor can portray IIMC conditions through an iPad during flight.
U.S. Helicopter Safety Team Issues a “Blueprint” for Confronting IIMC and Pilot Spatial Disorientation
Feb 16th, 2021
United States Helicopter Safety Team
Inadvertent Instrument Meteorological Conditions leading to pilot spatial disorientation continue to be a leading cause of fatal helicopter accidents. From 2000 to 2019 in the United States, 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 U.S. Helicopter Safety Team. “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.”
In response to this situation, the U.S. Helicopter Safety Team has developed a new Recommended Practices document focusing on “Spatial Disorientation Induced by a Degraded Visual Environment” and offering training and decision-making solutions.
“We are proposing a shift in the way we discuss, train and react to deteriorating or unplanned weather conditions,” added Mayhew.
The Recommended Practices document focuses on these training and decision-making actions:
- Avoidance of IIMC
- Preflight planning that includes enroute 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 preflight analysis, the preponderance of evidence can make that risk management decision straightforward and data-based.
Preflight Planning that Includes Enroute Decision Processes – Enroute Decision Triggers can be defined as a pre-determined set of conditions that “trigger” a decision point in the flight. When a preset decision trigger is reached, the pilot executes a predetermined action that was planned, briefed, and reviewed while at the planning table. The enroute decision triggers should be planned early in the preflight planning process to prevent other factors to impact them. These decisions should be planned and discussed for every flight – not just the flights where you anticipate weather to be an issue.
In-Aircraft Training that Simulates a Lack of Visibility – To be best prepared for a degraded visual environment, the USHST recommends a framework on which to build a comprehensive training program. This includes a no-visibility simulation while in-aircraft, simulators that offer visual illusion training and simulations that expose pilots to visual illusions and affect their vestibular system.
Program/Device May Be Ideal For Reduced Visibility Training
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. The USHST document also discusses techniques such as stabilized power, U.S. Army AHTTA training and the PAB method.
This USHST Recommended Practice document is intended to provide an initial framework for future comprehensive training packages aimed at reducing helicopter accidents stemming from spatial disorientation.
It is one of several significant safety initiatives developed by the USHST to reduce the number of fatal accidents.
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