Never Again: Big bang

It was a 100-degree-Fahrenheit day, and it took us a long time to climb to our cruising altitude of 13,500 feet. Over Hells Canyon, I reached for the radio to switch frequencies from Salt Lake Center to Seattle Center. There was a very loud bang and the airplane started to shake and rattle so violently I was not able to grab the radio knob. I started a shallow turn to the east, keying the mic to inform the controller, in a rather shaky voice, that we would be diverting to McCall Municipal Airport (MYL) because our engine was running a little rough.

My engine-failure checklist started with reducing power. The next item—enriching the fuel mixture—caused the engine to stop, so I followed advice I have been told many times: If something you did makes the engine quit, reverse your action. I pulled the mixture back until the engine returned to a very unstable life. I tried switching to the left and right magnetos with the same result. On both magnetos the engine returned to its original shaking and rattling 1,000 rpm.

With the checklist completed, I established best glide speed and headed for McCall. When I pushed the Garmin 296 GPS nearest-airport button, it told me that we had enough altitude at our current glide speed to make McCall.

We were over Oxbow Airport, deep in Hells Canyon. The prospect of spiraling to that short runway with a steep rock face approach into the canyon wall quickly nixed that option. The next runway option was New Meadows, a gravel strip with a hump in the middle and rock cliffs at either end of the runway—options not favorable without any chance for a go-around. We were committed to McCall. At about that time the air traffic controller gave me the temporary tower frequency at McCall. I had been monitoring the temporary McCall tower for a few minutes on the second radio because the airport was very busy with air tankers fighting fires, and I wanted to make sure I was out of their way.

By now I had the power adjusted so the shaking subsided to where I could grab the intercom knob and switch radios after thanking the controller for his help and declining the offer to declare an emergency.

I contacted McCall Tower and declined to declare an emergency for the second time that day. I gave my location and altitude, and the tower replied by closing the airspace and airport to all other traffic. When we passed over the second mountain range of the day with a violently shaking engine, making one-third power, the lake and McCall Airport were welcome sights.

I still had 8,500 feet of altitude when I reported the airport in sight. I would be landing on Runway 34, and we were still more than 3,476 feet above the runway. I told the tower controller we would circle over the lake to get to pattern altitude. The tower reminded me the airport was mine and I could circle over the airport instead. That was good advice, I thought, while turning on a left downwind for Runway 34.

I didn’t dare touch the power, so I deployed all the flaps, hearing my instructor’s voice from 25 years ago: “Don’t deploy the flaps until you know, you know, you can make the runway.”

We landed without incident. We taxied to the tiedown area, and the engine quit with a terrible screech. We soon learned the reason from a mechanic at the airport. The inside half of an exhaust valve, banging in the cylinder after the other half departed through the exhaust pipe somewhere in Hells Canyon, finally got a grip on the cylinder wall, which stopped the piston.

When we were safely clear of the airplane, I asked Joe if he had been scared. “Not so much after the initial bang,” he said. “You seemed to keep your cool.” We eventually caught a ride with a friend to Boise.

Looking back, I was glad for the Garmin 296 nearest-airport and glide-ratio features. Now I never fly my Cessna 310 without an iPad running Garmin Pilot. I don’t climb fast, and I lean the aircraft on a hot day. I still fly the Cherokee, but never over inhospitable terrain. If I do need to travel over the mountains, I make sure I have plenty of altitude to find a suitable place to land in an emergency. I won’t hesitate to declare an emergency in the future; it was nice to have the help and support of the controllers during a tense time in the cockpit. Even though I didn’t declare an emergency, we landed without incident, thanks to the controllers who treated the situation as an emergency.

Author Wilford Darcy Maag of Caldwell, Idaho, has a private pilot certificate with multi-engine rating. He has logged 2,500 hours.