1677D000-002 — Cooling Turbine Repair & Overhaul

Component Overview

The cooling turbine is the expansion stage of an air cycle machine within the aircraft environmental control system. Charged with high-pressure, partially cooled bleed air, it extracts energy as the air expands across the turbine wheel, producing a steep temperature drop that supplies conditioned air to the cabin and avionics. The wheel typically shares a common shaft with the compressor and, in three-wheel designs, a cooling fan, all supported on high-speed bearings. Service-driven distress includes bearing wear and increased shaft play, blade erosion and foreign-object damage, seal degradation that raises leakage and reduces cooling output, shaft imbalance, and thermal fatigue cracking. These conditions reduce efficiency and pack cooling capacity, prompting inspection, balancing, bearing replacement, and overhaul of the rotating group.

Aircraft Application

Part number 1677D000-002 (Cooling Turbine) is installed on the Pilatus PC-12. QTC supports operators and MROs servicing this platform with certified repair and overhaul.

Our Repair Capability

QTC repairs and overhauls 1677D000-002 to the original manufacturer's specifications under our FAA and EASA Part 145 approvals. Our team — including former OEM air cycle engineers — performs teardown, inspection, cleaning, component replacement, functional testing, and certification, returning a serviceable unit with the appropriate airworthiness release. We also develop repairs for rejected and beyond-economic-repair (BER) hardware.

View Air Cycle Machines capability →

Related Parts

Other cooling turbine part numbers we repair — view all Cooling Turbine parts →

Frequently Asked Questions