Helicopter engine overhaul, TBO and hot-section guide (M250, PT6, Arriel)

Helicopter engine overhauls run

Engine overhaul is the single largest scheduled maintenance event in a helicopter's life. The cost and downtime materially affect resale value, lease economics and the buy-vs-overhaul decision. Knowing the typical TBO and HSI intervals — and the realistic shop cost for each — lets you plan rather than react.

The numbers below are 2026 indicative ranges from active MRO quotes. Actual cost depends on the engine's as-received condition (run-out vs damaged vs FOD), exchange vs outright, and whether life-limited parts need replacement during the visit.

When you are ready to schedule, the ChopperSwap Services marketplace lists approved Part-145 MRO shops worldwide, filterable by engine type approval and region.

Steps

  1. Rolls-Royce M250 series (turboshaft) — TBO 3,500–6,000 hours depending on variant (C20/C28/C30/C47). HSI typically every 1,750–2,000 hours. Overhaul
  2. Safran Arriel (1B, 2B, 2D, 2S) — TBO 3,000–5,000 hours; module-based maintenance reduces single-event downtime. Module overhaul $80k–$220k per module; full overhaul $300k–$500k+. Approved network limited — book early.
  3. Pratt & Whitney PT6B / PT6C — TBO 3,500 hours typical. Hot-section every 1,750 hours. Overhaul $350k–$600k+ depending on model. Exchange programmes available through P&W ESP.
  4. Honeywell LTS101 / T53 — TBO 3,000–4,000 hours. Overhaul $200k–$400k. Approved overhaul shops fewer than M250 — schedule with longer lead time.
  5. Lycoming piston (HIO-360, IO-540) — TBO 2,000–2,200 hours. Overhaul $40k–$90k. Field overhaul more common than turbine; multiple approved shops globally.
  6. Plan downtime and freight — Turbine overhauls take 60–120 days at an approved shop, plus freight. For minimum downtime, schedule an exchange unit so the aircraft returns to service while your engine is in the shop.
  7. Source the core or exchange unit — ChopperSwap's engine marketplace lists serviceable engines and cores. Filter by model and TSO band; post an Engine Wanted request if nothing matches.
  8. Verify the MRO's scope — Confirm the shop holds current Part-145 approval for your engine type and is on the OEM-approved network for warranty-eligible work.

Why ChopperSwap

MRO directory

The Services marketplace lists Part-145 helicopter MRO shops with type-approval scope declared, filterable by engine and region.

Core and exchange supply

When you need a core for an exchange overhaul, the engine marketplace and Wanted requests find them faster than calling shops one by one.

Free for operators

Browsing the MRO directory, messaging shops and posting Wanted requests are 100% free.

Frequently asked questions

How much does a helicopter engine overhaul cost?

Rolls-Royce M250:

What is helicopter engine TBO?

Time Between Overhauls — the manufacturer's recommended interval between major engine overhauls. Model-specific: 2,000 hours (Lycoming piston) to 6,000 hours (some M250 variants).

What is a hot section inspection (HSI)?

A mid-life inspection of the turbine hot section (combustion chamber, turbine wheels, nozzle guide vanes) typically due at half-TBO. Cheaper than full overhaul but mandatory for continued airworthiness.

Can I do a field overhaul?

Piston engines (Lycoming HIO-360, IO-540) yes — many field overhauls are FAA/EASA approved. Turbines no — they must return to an OEM-approved Part-145 shop.

How long does a helicopter engine overhaul take?

Turbines 60–120 days at the shop, plus freight either way. Pistons 30–60 days. Exchange programmes minimise aircraft downtime to days instead of months.

Where can I find a helicopter MRO shop?

ChopperSwap's Services marketplace lists approved Part-145 MRO shops worldwide, filterable by engine type and region. Free to browse and contact.

ChopperSwap
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