Page 23 - Volume 11 Number 3
P. 23

The first story involves an old friend of mine with whom I have conducted initial and recurrent King Air training since the 1970s. When I first met this fellow, he was flying a B90 and the various companies he advanced with moved up the King Air ladder so that he was checked out in just about the entire King Air lineup by the time he retired. Although he never argued forcefully with me about ice vane usage, being a kind southern gentleman, I know that he was reluctant to deploy the vanes unless the airframe was collecting significant ice. Nothing I taught could convince him that he was playing a dangerous game.
Then one evening while at home, I got a call from him. It went something like this: “Well, Tommy (He always called me that!), I guess I should have been listening better to you all these years when you preached about ice vane usage. Today, at FL280, we were in visible moisture that was so thin it could have been the contrails of a 747, 20 miles ahead! Of course, I didn’t activate the engine anti-ice. When I started the descent, and changed the power setting, I noticed that things weren’t matching up like they did before. This continued through the landing so I had the mechanics take a look. When they got the flashlights and mirrors to look at the first stage compressor blades, they reported bent blades on both engines. So now we are sending our engines out for repair and will install a
couple of loaners in the meantime. I couldn’t believe it, but I saw it! You were right!”
The second story involved a B200 also flying in the upper 20s, but this time it was night over a dark expanse of the Australian Outback. The pilot noticed that the nav lights were giving a glow on the moisture they were in, so he extended the vanes. He was not sure how long he had unknowingly penetrated the tops of these smooth clouds, but doubted that it could have been for more than a few minutes. When he broke free of the clouds and retracted the vanes, he noticed a 400 ft-lbs, or so, torque split. In the descent, one engine started fluctuating and actually expelling some visible flames at times out of the exhaust stacks. That engine was found to have suffered first stage compressor damage – a bent blade.
For many years now I have always included a copy of a Pratt & Whitney Field Note in the section of my training manuals dealing with ice protection. I am sure those who have trained with me in the past or who have attended the King Air Academy recently have read this before, but I want to print it here for those who have not yet seen it:
In April 1982, a general correspondence was issued concerning the subject of Compressor Ice FOD (Foreign Object Damage). Winter is here again and after three incidents this month,
MARCH 2017

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