HEMS operations in adverse weather conditions
The No 1 rule of aeromedical helicopter operations is that all crew go home at the end of the shift. In the first of four features, Aeromedical Pilot Mike Biasatti recalls some of his stickier moments in the right-hand seat during 20 years flying helicopter EMS operations in the US
Every six months for almost 20 years it’s been a condition of my continuing employment as an aeromedical pilot for one of the largest aeromedical operators in the US that I take a Part 135 Check Ride to evaluate my knowledge of various aspects of aircraft operations. This includes weather, flight rules, aeromedical factors, aircraft specific questions, performance, ATC procedures and anything else contained in the FAA Practical Test Standards (PTS). In addition to a verbal examination, a flight test is required to determine my ability to successfully perform the required maneuvers at a commercial pilot standard.
Every examination always began with the same edict – the success or failure of my check ride and resultant continued employment was dependent on my ability to demonstrate mastery of the aircraft with the successful outcome of each task performed never seriously in doubt. I often joked (in my internal voice) where the line between 'in doubt' and 'seriously in doubt' was, but the PTS was clear in the expectation and so was I.
As I approach and reflect on my twentieth year of flying helicopter EMS operations in the US, I can recall a few flights where my compliance with that PTS edict was called into question. In any operation there is always room for improvement and in my opinion the sign of a true professional is a commitment to never stop learning and improving. With that in mind, over the next four issues I’d like to share some of my 'oh sh%t' moments, where the successful outcome of a maneuver came into doubt, what I learned, and what I would do – and now do – differently. All risk assessment values taken into account with these conditions allow me to follow the number-one rule of aeromedical helicopter operations – all crew go home at the end of the shift.
The call came in around 02:00hrs to fly about 60 nautical miles west to a remote hospital and pick up a patient needing rapid transfer to hospital with an orthopedic surgeon. This would be our third flight of the night. A quick look at the radar showed a fair collection of thunderstorms about 20 nautical miles south of our flight path, slowly moving south and away from our course out and back. The wind at our base and the destination hospital was particularly strong at the surface (20 knots with gusts to 30 knots), but nothing we hadn’t routinely flown in before. This flight took place some years ago when weather information was not what it is today. The most thorough source of weather intelligence at that time was a call to the Flight Service Station on a landline phone (no smart phones back then), but I had the radar depiction and a collection of METAR reports (Meteorological Aerodrome Reports) to guide my decision to accept the flight. No portion of the route was going to require an instrument flight rules (IFR) leg, so in hindsight I may have allowed that to influence my decision to not seek out a more complete weather briefing – first mistake.
That night, the crew I had (flight nurse and flight medic) were very experienced, having flown EMS for many years. As we arrived at the helicopter, the medic commented about the wind but didn’t express being uncomfortable with departing on the flight. After I completed all preflight and run-up checks, we lifted off and headed west. Immediately the aircraft was getting tossed around. We began our climb up to cruise altitude, which took unusually long with a continuous series of up and downdrafts. The medical crew received their patient report after we’d been airborne for about 10 minutes. Their patient had a spinal injury and the discussion ensued as to whether the flight conditions were appropriate for that particular person, given the strong winds and moderate turbulence we were constantly experiencing.
Abort the flight
Aircraft control was considerably challenging, attempting to maintain course and altitude. Travelling at about 2,000ft AGL unaided (it would be another 10 years before NVGs became available to the civilian market) over unlit (albeit flat) terrain, the medical crew made the decision to abort the flight. As I started to turn the aircraft to return to base, the helicopter began to roll on its side instead of bank and start to turn. Right then the aircraft experienced a downdraft, the significance of which was lost on me visually, but the severity of which I was made immediately aware of aurally as the TCAS (Terrain Collision Awareness System) began screaming in my ear – ‘WARNING TERRAIN, WARNING TERRAIN, WARNING TERRAIN’.
From our 2,000ft AGL cruising altitude, in what felt like an instant, this audible warning indicated we were now within 300ft of the ground. I raised the collective, applying full power in an attempt to climb. Cyclic inputs to turn continued to result in the aircraft leaning more. At this point I, too, felt like a passenger.
The nurse who was riding up-front asked in a panicked tone what was happening and in my very best calm tone I said to give me a minute, asking him to change a com radio frequency for me. Essentially I was trying to distract him while I determined the best course of action. I think (and this was a long time ago) my exact words were 'give me a second while I regain my composure'.
Feeling as if continued attempts to turn the aircraft would result in the same previously experienced rolling moments, and knowing that an uncontrolled airport was about 10 nautical miles straight ahead, I continued on and advised we’d be landing there to reassess everything.
As we neared the airport and performed the approach, I landed on the runway. The paramedic who was riding in the back asked why we had landed on the runway, to which I responded ‘give me a few minutes’; I had a severe case of white-knuckle syndrome.
After a few minutes, we hovered to the ramp and shut down. I contacted our dispatch and advised them we’d be on the ground until the sun came up in about three hours’ time The medic slept on the flight board, the nurse on the ramp next to the helicopter and I just paced for the entire three hours. Finally, as the sun rose we lifted to return to base in what was a relatively uneventful leg. As I entered the base after landing, the local news was on and the meteorologist was referencing last night’s wind. All I remember hearing were the words ‘anomaly’ and ‘wind shear’.
Investigate thunderstorm activity
In the many years that have passed since that evening, I’ve discussed the flight with various training captains, instructor pilots and more experienced pilots to learn from what happened and be better equipped to recognize the factors that probably caused the conditions we experienced. The hope is I’ll avoid that situation again and handle it better if I ever find myself flying in those conditions in the future.
Collectively, the things I’d do differently would include taking the time to further investigate any thunderstorm activity within 20-plus nautical miles, but even go one step further and widen that separation to 30 or even 40 miles. In the case of a multi-cell thunderstorm cluster, perhaps require even greater separation. In hindsight, my glance at the radar before accepting the flight was probably part arrogance, as well as not having been exposed to such severe weather in past flying.
Later, I looked at the radar images from the time when I accepted the flight and what I dismissed as a single thunderstorm moving away from my course was in fact a collection of air mass thunderstorms that covered several counties. Advisory Circular 00-24C refers to it as a Thunderstorm Cluster (Multi Cell).
Surface weather is helpful in assessing safety and suitability of a flight request, but I now keep in mind that we aren’t spending a majority of our flight-time at the surface. A further investigation of things like Winds Aloft, CWA (Centre Weather Advisory), SIGMETS (Significant Meteorological Information), Convective SIGMETS, and any PIREPS (Pilot Reports) could have yielded a greater degree of understanding of the weather risks associated with the convective weather depicted on the radar. Even today, I find that after accepting a VFR flight and departing based on METAR reports, flight visibility and reported surface visibility can vary significantly.
Electronic Flight Bag
Today, the abundance of weather tools available in the cockpit while on the ground is amazing. Most aeromedical operators in the US as part of an Electronic Flight Bag (EFB) issue the pilots with iPads with a full complement of weather resources. None is more impressive than ForeFlight, an amazing compilation of the most complete, intuitive weather software that they never stop improving upon. For young pilots, the challenge isn’t having real-time access to weather information now, it’s committing to putting in the time to learn how to effectively use these amazing tools and properly interpret what they are telling you. Learning takes time, and to consider oneself a professional in any field one must never stop learning.
Number-one rule satisfied
As for the course of action I took of landing and waiting for sunrise to re-evaluate – well, at the time I was the junior pilot on staff and my actions were previously unheard of at the program I was working, so as you can imagine there was some mild hazing, along with a newly earned nickname, but all good natured. Even as I look back after all these years, I’m confident in the decision to park the aircraft until the sun came up.
The old saying rings true today as it did back then: 'I’d rather be on the ground wishing I were flying, than flying wishing I were on the ground'. That night I was certainly the latter wishing to be the former. When all was said and done, I complied with rule number one – my crew and I went home after our shift, just a little later than normal.