Air medical helicopter operations continue to improve on safety with a focus on simulator training, night vision goggles and technology for navigation and terrain awareness. So why do we still have accidents due to loss of control in instrument meteorological conditions (IMC)?
There continue to be many accidents that fall into this category. Loss of control after entering low visibility conditions has proven to be fatal in many helicopter accidents.
To start with, let’s go back to basics. IMC can be dangerous as outside visual reference is lost without preparation to transition to an instrument flight rules (IFR) flight. We may not realize just how much we rely on visual cues from outside, but we find out very quickly when the visual cues are no longer there. The ‘inadvertent’ part of these kinds of accidents makes it even worse, because we weren’t expecting the lack of visibility. Therefore, we may not be prepared to respond to the situation. This is a very dangerous condition that often leads to tragedy.
Feeling the pressure
Preflight preparation, including an accurate weather assessment, is critical to making a good decision. There are tools and resources to make this easier but still the decision to go sometimes outweighs the reality of the danger. So why the decision to go? Perhaps the weather forecast seemed better at first glance, but most often it is the pressure to take the mission. The pressure can come from a variety of sources. Pressure can be self-induced by the desire to fulfill a lifesaving mission. Complacency can also feed this pressure because there may be an attitude that ‘it can’t happen to me’.
In a recent accident report from the National Transportation Safety Board (NTSB) in the US, pressure to go was linked to a poor safety culture. A corporate culture that puts performance and profit before safety can lead to poor decisions based on job security and keeping the management satisfied. Safety culture always starts at the top, and if incorporated into a solid safety management system (SMS) will often lead to safe procedures based on data and lessons learned. The NTSB reported that the accident was an inadvertent entry into IMC (IIMC) with multiple fatalities; and that the company culture was to pressure crews to accomplish as many missions as possible with little oversight on policies and procedures.
If we use this as a case study, the facts take a lack of safety culture to the extreme. The pilot did not get a shift change briefing, weather briefing, do a risk assessment or start the helicopter. The flight was accepted by the pilot going off shift without a thorough weather briefing. He started the aircraft for the incoming pilot who took off in the dark without NVGs and flew into snow showers and crashed. There are so many wrong decisions that it must go back to a culture that allowed that.
Follow the rules
Most operations have a more standardized culture with oversight. Can IIMC still happen? Yes. If any of the procedures are missed there can be a break in the chain that can cause an accident. The more that are missed, the greater the chances. If a pilot doesn’t get a complete weather briefing and check for any other programs turning down the flight, the risk is greater. If the pilot does not do a risk assessment or a crewmember does not express concerns about weather or fatigue or other questionable issues, the risk increases. It falls back to a safety culture allowing the informed decision-making process and situational awareness that can reduce the risk.
Practise, practise, practise
Training for the possibility of IIMC is also important. The most effective training requires an honest self-appraisal. These are the facts:
- Most helicopter flights are done under visual flight rules (VFR) – it is the nature of most missions.
- Instrument skills are perishable. The expiration date of these skills varies by the level of experience and ratings; however, these skills are perishable and will expire for everyone that does not practice. If not practiced often, the skills become weak at best.
- Weak skills, combined with an unplanned encounter, can be fatal.
There are several ways to practice all the necessary flying skills with varying degrees of effectiveness. The most effective is using a simulator where you can practice to all levels of IMC conditions with little or no risk to person or aircraft. Many pilots say that training in a simulator can be very humbling because they are often not as proficient as they thought they were, and this is especially true for IIMC situations. In other emergencies such as power loss or hydraulic failure, we have learned procedures that can almost be classified as muscle memory because we train the same procedures, with the same checklist, each time. In the case of IIMC, muscle memory seems to fade as visual cues are lost. The sudden realization that you can’t see can lead to questions like ‘I don’t know what to do because I can’t see the results of what I am doing’, and ‘am I climbing, descending, banking’?
Some muscle memory for IIMC can be learnt in a simulator with concentrated practice or in aircraft training with a view limiting device. Training in an aircraft can be effective if the pilot truly uses a view limiting device as designed. Training in an aircraft does have some limitations. Under normal circumstances, you can’t actually fly in IMC conditions during training, so the inadvertent part is not accurate when you have to take time to put on a hood in order to train. The training does allow you to practice flying by instruments and sharpen your scan which can be crucial to surviving a real encounter.
The solutions are really not complicated. If VFR cannot be assured, then the pilot and aircraft must be able to make a safe IFR transition. If that is not possible, the flight should not happen. Safety culture starts at the top and allows for decisions based on safe operation, crew readiness and situational awareness. Air medical operations can be safe, and good decisions really do #makeadifference!