Engine Reliability



Engine Reliability in a dangerous flight environment.

It has been a year since I began flying med-evac Helicopters and it has been an exciting experience. In this article I thought that I would recap a few of my thoughts and experiences of this past year as I look forward to another great year of helicopter flying, albeit in the private sector. The vast majority of my helicopter experience has been piloting Rotorway Experimental helicopters. For many years I dreamed of flying the “big” helicopters and last year I got that opportunity.

I had always thought that turbines were the power plant of choice for helicopters. Aside from my hours instructing in Jet Execs, I had limited experience with this type of power plant. Common thinking is that Turbines are far more reliable than their certified piston counterparts, in turn the certified piston engines are far more reliable than those uncertified engines found in most experimental helicopters.

As a Part 135 certified med-evac pilot, I was finally going to be flying one of my favorite helicopters. This helicopter, with it’s big turbine engine, would take me anywhere with near absolute reliability, or so I thought. My new employer started me out flying day shifts and within a few months I was flying night shifts as well. My “hitch” consisted of 7 straight 12+ hour shifts.

Following my 7 days of flying med-evac missions I would usually leave for 7 straight days of Rotorway or R22 flight instructing. The med-evac flights were usually conducted over vast stretches of oak tree forests, lakes, and vast wilderness areas. I knew that I was flying with a reliable turbine engine, and that perception reduced the pucker factor of these flights considerably. Often during these flights I would look at the terrain below and know that I would never attempt to fly an experimental helicopter over these areas due to their less reliable power plants.

I was often told that flying an experimental helicopter was one of the most risky forms of flying. After I started flying med-evac helicopters I realized that the thousands of hours that I have accumulated flying hundreds of different Rotorway helicopters was relatively safe in comparison. I often would launch from our med-evac base and fly off into the dark with only rough GPS coordinates provided by dispatch. While I was en route I was told what to look for on the ground to help locate the scene upon arrival. Sometimes the scene was easy to find by the myriad of flashing emergency lights, other times I was looking for a solitary porch light flicking on and off to signal the location of the remote residence where I was to land.

Power lines and towers are very difficult to see at night while one is making an approach into a dark LZ lit only by the night scanner beacon on the helicopter. It could take only a single lapse in concentration or one error in judgment by the pilot and the entire crew and patient could meet an untimely end. Many times the local weather reporting stations were over 50 miles from our scenes so I had to determine wind direction and visibilities once I arrived overhead, and do that in complete darkness. The element of danger was real and often palpable.

After around 6 months flying med-evac the Bell 206L1 Long Ranger that I had been flying experienced a complete engine failure. This occurred over a heavily forested area while transporting a patient to a local hospital. I was flying the night shift and this happened during the day shift. Fortunately the pilot was able to auto rotate into a small field barely making it over the tree tops before sliding it onto the rough ground of the small clearing. The medical crew thought that they were going to die and braced for the crash that did not happen. The medical crew and patient were taken by ground ambulance to the Mountain Home, AR hospital that they had been flying to in order to complete the patient transport. A company mechanic later arrived at the broken helicopter by ground.

That same night directly after shift change I flew with the same medical crew in a replacement 206L over that same area and we were all hoping that this engine was in better shape than the one that had just quit. I was glad that my autorotation skills were current. We had been directed to land next to the downed helicopter in the small clearing so that the mechanic could remove all of the medical equipment from the downed ship and install it into the replacement ship that I was flying.

We arrived in the general area by the GPS coordinates given by dispatch but it was totally dark and a moonless night. I called the mechanics cell phone and asked him to turn on the anti-collision light on the grounded helicopter, which he did and I located it's position. It was a tight approach putting a second Bell 206 Long Ranger into that tiny field next to the broken one but I did and we transferred all of the required equipment.

During the following week our regular base 206L (Rocket 88) was in the shop getting a new engine and I was flying a freshly refurbished replacement Long Ranger. On the night following the engine-out of our base helicopter, I got a call to fly to the scene of an injury accident out in a mountainous part of Arkansas. There was no moon visible, and the area had no ground lights because it was located in a portion of the vast Mark Twain national forest. I had only rough GPS coordinates to get the crew to the scene. An engine failure during this flight would have been disastrous.

As we approached the scene of the accident the only ground reference that I had was the single red emergency light on the roof of the ambulance. The night was extremely humid so the search light only illuminated the water vapor in the air much like turning on the high beams of your cars headlights in the fog. Visibility was nil until I was within 200 feet of the ground at which point I could start to make out surface features.

It is a real challenge to drop into a black hole in a helicopter at night while knowing there is steep terrain, mountain peaks, power lines and tall trees below that cannot be seen and the possibility of an unlighted tower. While making my final approach I reflected on the recent engine failure of our base helicopter. I would have been flying that helicopter this night if the engine held out a few more hours before giving up.

All went well, we landed and loaded up the injured party and readied for takeoff. Again my crew and I had to put our full faith in the engine to get us out of the scene and to the nearest trauma center. This engine did it's job and we completed our mission.

We do put an awful lot of faith in the engines that power our helicopters. Turbine engines are very reliable as are piston engines. We need to remember that all engines can fail at some point. In the EMS world we are called on to fly in less than favorable conditions at night, and into places that we wouldn't consider taking our experimental helicopters. The reason we make those flights is that the mission is different. Someone’s life is at stake and it is the job of the med-evac crew to pick them up and transport them to the nearest trauma facility.

During the past year my base experienced at least 3 partial power(engine) losses necessitating canceling missions that placed the helicopter into the maintenance shop. We also had that one complete engine failure. Our base flew approximately 2,000 hours last year . I know that seems unusually high failure rate for a turbine engine but that is what happened to our base ship. It is important to note that we need to do everything within our power to make sure that the engine, electrical, and mechanical systems on our helicopters are installed and maintained properly so that we do not experience an in-flight failure. For this reason there are several groups that are exploring optional engine and drive systems for the Rotorway helicopter. Stay tuned, great things are on the horizon.


Orv Neisingh

Sho-Me Helicopters, LLC