I had the opportunity to practice some emergency skills yesterday. I was flying a route I fly often, from McBride CAV4 to Grand Forks CZGF, via Kinbasket and Arrow lakes. I was southbound over the Mica dam about 1500' AGL (were lots of small weather cells keeping me from staying higher) when the engine suddenly started vibrating heavily and the nose dipped due to loss of power. I was at about 130mph, so I immediately trimmed up (trade airspeed for altitude) for best glide. I had highway 21 below me, but I didn't relish the idea of an off-airport landing. I changed prop speed and throttle, mixture and carb heat to try and find any improvement.
Ultimately, I ended up at near full speed and throttle which provided sufficient thrust to maintain altitude. Once the plane was stabilized, and the vibration wasn't threatening to break the plane, I decided to continue ahead, keeping the highway within gliding range. The Mica Creek strip was ahead, but I soon saw that it had a couple of feet of snow on it so that was not an option.
I tried calling Pacific Radio, and tried the local frequencies, but could not raise anyone. I always keep one radio on 121.5, so I broadcast a PanPan call which was picked up by AC214. They relayed my call to Vancouver Centre. Once they were passing out of range, WJ177 picked up the communications and continued to relay my status as I made the 60 mile journey to Revelstoke (the nearest field).
I made a straight-in approach on Rwy12 - as soon as I idled down for the decent the engine threatened to depart the AC so I tried to shut it down completely, but it continued to windmill and I didn't want to mess up my approach trying to stop it by pitching up. I made an uneventful landing, and almost made the taxiway. I was met by two RCMP cars and a fire truck. Everyone was pleased that they were not needed.
Things I thought might be helpful to pass on:
- Make best use of any airspeed above best glide speed by climbing
- Maintain best glide, even if the engine is still running at some power, it will buy you distance, or as I did, get you to a good landing spot, it will always get you the most time to maximize your landing choices
- In the mountains, especially when low down, radio range is poor. Don't be afraid to make use of the jets with a clear signal path to you - that is why they monitor 121.5. I didn't request emergency vehicles, but I was glad to see them and they were happy not be needed. If things had not turned out well, help would not have been far away, and they were looking in the right place because the jet pilots had been able to pass on my location and intentions
- Don't get flustered or panicked - you make better rational decisions when you are calm. Even at 1500', I had at least two minutes to determine whether I was landing on the road, or if I could maintain altitude. Two minutes is a looong time in that situation!