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Notes on Flying through Volcanic Ash

Mount St Helens in 1980ON THE 20TH of May 1980, I was sitting in the right seat of a C-141 in Utah with a crew about to finish our fourth sortie carrying Minuteman missiles between Utah and Montana. These sorties used max takeoff power from the C-141 Starlifter because the ICBM missiles weighed nearly 70,000 pounds and filled the entire cargo compartment. But after the last run, we knew we could depend on the gas-guzzling Pratt & Whitney TF33P7 engines. They pushed out 20,000 pounds of thrust each and they were highly reliable. So when we wrapped up the work in Utah, we departed Hill AFB with an empty load and rocketed to FL350 for a short trip into California. The route took us due west then across the Donner Pass into Travis AFB. I still remember the uneasy feeling I got when Hal the aircraft commander throttled back at level off because the number four engine burped and shot a 10-foot plume of flame out its front compressor. The whole aircraft shuddered and our main air conditioning pack started a wild temperature fluctuation. We discovered later that we were approaching the leading edge of the Mount St Helen's volcanic ash cloud and that the cloud extended higher than several weather experts had predicted. Since we were nearly directly overhead a military operating area, we told Air Traffic Control we were descending immediately and returning to our departure base. A half hour later we were back on the ground. We spent three days in Utah waiting for a ride back to California. Two of the aircraft's engines had to be repaired at a cost of $109,000 each. I filed away a "note to self" about flying downwind of volcanoes when I saw the final incident report and cost of our 43-minute flight. It's more dangerous than flying into blowing sand. Today, most of Europe is closed to flight because of a large volcanic ash cloud extending from Iceland to the south of France. Aircraft engines represent nearly 35% of the value of a new commercial airplane. As I discovered, those well-tuned pieces of machinery don't like sucking ash instead of air.

Captain Bernie Goldbach flew nearly 2000 hours in the Lockheed C-141. Some flying shots prove it.

Ronan McGreevy -- "Former test pilot recalls flying through volcanic ash" in the Irish Times, 20 April 2010.

There is volcanic ash on my car. (The Qik clip proves it.)

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