OPERATIONS · ISSUE 01

Inside an N830JB engine teardown.

The Citation V is in for dual JT15D-5A overhauls at TMS Aviation. What that actually looks like — TT, cycles, hot-section status, LLPs, and the per-side cost picture lenders are asking about.

By · 12 min read ·

N830JB is a 1992 Cessna Citation V, S/N 560-0164, currently mid-refurb under B&N Transport. Total time at the start of the program: 11,493.1 hours. Cycles: 8,852. Both Pratt & Whitney JT15D-5A engines are coming due, so we're doing them as a paired event at TMS Aviation.

The point of this piece is to show what the inside of one of these programs actually looks like — for owners thinking about a similar refurb, for lenders evaluating airframe value, and for anyone who's about to write a check that has the word "overhaul" anywhere on it.

Why both engines, why now

The 5A doesn't have a hard TBO in the manufacturer's published schedule the way some piston engines do. What it has is a hot-section inspection interval and a lifetime list of life-limited parts (LLPs) on rotating components. When the LLPs come due, the engine effectively comes apart whether you call it an overhaul or not. We're at that window on both sides, plus the hot-section deltas tell us we're not going to get clean condition reports for much longer.

Doing them at the same time isn't a vanity move. It's the right operational call: matched cycles going forward, single inspection cadence, one downtime instead of two.

The numbers we're tracking

Per-side scope

What lenders are asking for

The single biggest delay in any engine program isn't the shop. It's the logbook. If you don't have clean, ordered, scanned logbooks before the engines come off the wing, you're going to be answering the same lender question for six weeks.

What this article will cover in the full version

This is the launch stub. The full piece will walk through:

Updates will land here as the program moves.

Frequently asked

What is the TBO on a Pratt & Whitney JT15D-5A?
The JT15D-5A does not have a single hard TBO interval the way some piston engines do. It uses a hot-section inspection interval and a list of life-limited parts (LLPs). When the LLPs come due, the engine effectively comes apart whether you call it an overhaul or not.
How long does a JT15D-5A overhaul take?
Typical shop turnaround is 8–14 weeks for a hot-section overhaul plus LLP replacement, varying by parts availability and inspection findings.
What does a JT15D-5A overhaul cost?
Per side, $300–500K is a common range for a hot-section plus LLP refresh, depending on the cycle count, condition reports, and which parts step out vs back in.
Why do both engines at the same time?
Doing both engines at once gives you matched cycles going forward, a single inspection cadence, and one downtime instead of two — which materially affects resale and lender appraisal.
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