Page 21 - Volume 13 Number 2

In the hangar, the mechanic quickly pulled the forward cowling to gain access to the detector. He positioned a metal pan to catch the oil and removed the detector. As the oil fell into the pan, I swear we could hear metal hitting metal! Maybe not, but that oil was thick with metal contaminants. Have you heard the line about “Pieces being big enough to have part numbers on them?” That’s about what we had here! I’m sure glad we shut it down expeditiously!
By the way, both this engine and its partner on the other side were very close to the suggested 3,600-hour TBO, so both were sent out for overhauls.
The F90 model made its appearance in 1978. Like the other models being produced then, it also had the chip detector on the red warning annunciator panel. As time passed, it became obvious that some chip light illuminations were indeed a precursor or indicator of major engine damage whereas other cases simply were lint-related.
At some point a meeting of Beechcraft engineers, pilots and lawyers was held and the issue was discussed in- depth. I was not in attendance, but I am guessing it may have gone something like this: “Should we really treat this basically equivalent to an engine fire, even when there may be no immediate problem? Aren’t we exposing our company to possible legal action if a pilot were to botch a single-engine approach and landing, when in fact the airplane didn’t need to be single-engine at all?”
Based on this type of concern, decisions were made to (1) change the annunciator in forthcoming models from red warning to yellow caution, and (2) insert a checklist step demanding/suggesting the pilot not shut down the engine unless abnormal engine instrument readings were observed.
Having the annunciator red in some models and yellow in others has been a head-scratcher for many pilots and training providers for a long, long time. Realize that there is no difference in the installation whatsoever except for where the light is placed and what color it is. If your flight department has, say a straight 200 and a 350, the light will be a warning in the 200 and a caution in the 350. Therefore, should you actually react differently depending on which airplane you are flying that day?
We each must answer that question for ourselves. Based on what I have presented here, I imagine you can guess my personal position. Yes, so long as “conditions permit,” I will be pulling the condition lever and feathering the prop quite rapidly. Now, granted, I have lots of single- engine time in King Airs because of the thousands of hours spent instructing in them. Since your level of one-engine-inoperative experience may be significantly less, I can appreciate your possible reluctance to do an immediate shutdown. That’s understandable and just fine. After all, there is a reasonable chance that the illumination does not indicate that a catastrophe
FEBRUARY 2019
is imminent. And if the engine does indeed blow up? Well, that’s a time to call the insurance agent.
I’ll wrap this up by giving you, as Paul Harvey used to say, “The Rest of the Story” concerning the scenario at Rock Springs. When the engine was sent in for repair, the shop reported this interesting bit of news: They said they had never seen an engine with so much destruction in the power section and yet the compressor section was fine. The engine had been shut down before the contaminated oil had clogged the main oil filter enough to cause its bypass to open. Hence, the No.1 and No. 2 bearings – the ones that support the aft and forward ends of the N1 or Ng gas generator shaft – came through unscathed. Food for thought, eh? KA
King Air expert Tom Clements has been flying and instructing in King Airs for over 46 years, and is the author of “The King Air Book.” He is a Gold Seal CFI and has over 23,000 total hours with more than 15,000 in King Airs. For information on ordering his book, contact Tom direct at twcaz@msn.com. Tom is actively mentoring the instructors at King Air Academy in Phoenix.
If you have a question you’d like Tom to answer, please send it to Editor Kim Blonigen at editor@blonigen.net.
KING AIR MAGAZINE • 19