Page 18 - Volume 13 Number 8

Hot Section
Inspections Revisited
by Dean Benedict
Recently I was consulted about a PT6 undergoing a Hot Section Inspection (HSI). It began benignly enough; the hot section itself was in decent shape. But things took a left turn when a broken diffuser tube was found. This meant the rest of the engine (the “cold” section, if you will) had to be removed and inspected. The teardown of the compressor section revealed eight bad compressor blades (not to be confused with the CT blades on the turbine wheel). The engine shop tab is over $100K and the job is not yet complete.
Ballpark Estimates
King Air owners and operators need to know what it costs to maintain the aircraft, but when I’m asked
for a ballpark figure on the HSI, I balk at the question – especially with someone new to King Airs. I hate to discourage them with the worst­case scenario, nor do I want to mislead anyone with a lowball estimate. When I had my shop, my wife often fielded this question. She explained that once the hot section is opened up, all sorts of things might be found that must be addressed. Her answer was “anywhere from $15,000 to $150,000, per side.” That’s a really big ballpark!
King Air owners who aren’t turbine engine experts can have a hard time wrapping their minds around the idiosyncrasies that can crop up during the HSI. And it’s especially frustrating when, prior to the inspection, the engine(s) seemed to be running great.
16 • KING AIR MAGAZINE
AUGUST 2019
MAINTENANCE TIP