A battlefield repair

Something is wrong with my engine. It sounds all right: A steady roar, deafening without a headset. It feels all right: The vibrating of the airframe rattles my bones in a steady, consistent way. Oil pressure is good. Oil temperature is good. The cylinder head temperature is normal at 375 degrees.

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But something is wrong.

My RPM is down. A lot. And so is my speed. Grandma Jones, somewhere down below me in her rusty 1962 Ford Fairlane, is driving to the grocery store faster than I’m flying.

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I fiddle with the mixture again. No luck. What little power I have is the best I’m going to get. I pulled the carb heat for the descent from 9,500 feet over New Mexico to 5,500 feet south and west of Lubbock to duck under the Lancer MOA, and while it doesn’t seem like a carb ice kind of day, there’s no harm in cycling it one more time. Just in case.

What’s carb heat? Airplane carburetors use a venturi to mix fuel vapor and air into a volatile mix that’s fed into the cylinders, where the mixture is ignited to move the pistons. Venturis lower the temperature of the incoming air by as much as 70 degrees, so it’s possible for ice to form inside a carburetor even on a warm day. To prevent this, planes are equipped with a carb heat control that simply diverts heated air from the engine to melt off this unwanted ice, should it form. The downside of using carb heat is that it robs you of power. But the only other option—when ice forms—is no power at all.

I reach down and pull the handle. It comes clean out of the dashboard. Completely. Into my hand.

Oh shit!

Naturally I try to stuff it back in, as if that will fix it and make the problem go away.

This does not work.

Fifty miles from my intended fuel stop, but with enough power (barely) to stay in the air, I decide to stick with my flight plan. Once on the ground I’ll try to find a mechanic. Now, many pilots in my predicament would use Garmin Pilot or Foreflight on an iPad to find the nearest airport known to have a good repair shop. I have an iPad with Garmin on it, but I have a problem: I have an airplane that requires a lot of attention. This is a very hands-on airplane. In fact, I’m developing a callus on my left hand from all this long distance flying to-and-from the air races.

If I take my hand off the yoke to poke at an iPad for more than 20 seconds, the plane snaps right and noses over in a good imitation of the Pappy Boyington’s Corsair rolling into a strafing run in the opening credits of the 1970s TV hit Baa Baa Black Sheep.

I choose to stay calm and fly on.

On the ground at Winston Field in Snyder, Texas, the resident mechanic is nowhere to be found. Maybe he went flying. Maybe he went fishing. Maybe he went fly-fishing. No one is sure. But a recently retired Air Force mechanic helps me diagnose the problem.

In the Plane Tales Plane, at least, the carb heat is actually held closed by a cable. Pulling the handle in the cockpit doesn’t open the heat vent, rather it releases the tension on the cable and lets the air valve flop open on its own, diverting engine-heated warm air into the carb to melt that ice.

The bracket that held the cable tight to the airbox, letting it keep the carb heat off, had simply fallen apart from old age, releasing the tension and for all practical purposes leaving my carb heat “stuck” in the “on” position. That’s a bad recipe for racing, as using carb heat reduces power by a ton. My guardian angel mechanic votes for a spot weld, but doesn’t have the gear on hand, so no kidding, he uses aircraft-grade bailing wire to rig a temporary fix, which he reckons will probably get me through my race and back home again to Tessie’s regular mechanic, who no doubt has a spot welder.

I take off again and start barnstorming my way across Texas to Taylor, just north and east of Austin, the engine running right as rain again.

Bailing wire! Who knew? Go Air Force!

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