Page 19 - Volume 13 Number 8

Compressor blades from the compressor “cold” section of the engine. Some of the blades are good (shown by green line) and some are worn (shown by red line).
Sometimes you get a big zig when you expected a little zag. I remember the time I had two model 200s in my shop going through hot sections at the same time. The outcome for each was the opposite of what one would have logically expected.
King Air A versus King Air B
King Air A was a B200 with ­42s (and Service Bulletin 3360 completed on each). It had around 5,500 total hours on the engines and 1,800 hours since overhaul. The tab from the engine shop was around $43,000 per side (this was about eight years ago). That didn’t include items like the R&R assist by my shop, freight charges and miscellaneous expenses.
King Air B was a straight 200 with ­41s, both of which were on the MORE (Maintenance On Reliable Engines) program. One engine had roughly 9,800 total hours and the other had around 11,000 total hours.
AUGUST 2019
Both engines had run approximately 4,800 hours since overhaul. The last hot sections were 1,500 hours ago when these engines were first put on the MORE program. In accordance with the program, they were due another HSI.
One might assume that the older engines on King Air B, with 4,800 hours since overhaul, would have hot sections far more expensive than King Air A. Surprisingly, the for one engine on King Air B, the hot section was a mere $18,000 – nearly best­case scenario. The other engine was less cooperative and the engine shop’s tab came to $58,000.
What Goes Wrong?
It is very troubling to pilots and owner­operators when they’ve seen excellent engine performance indications in the cockpit, but at the HSI they get hit with astronomic bills. Understandably, many feel they are at the mercy of the engine shops.
KING AIR MAGAZINE • 17