790298-4 — Heat Exchanger Repair & Overhaul

Component Overview

A heat exchanger transfers thermal energy between two fluid streams without mixing them, and in aircraft heat-transfer systems it most commonly cools hot engine bleed air using cooler ram air or another medium. Of brazed plate-fin construction, it routes the streams through alternating finned passages so heat conducts across thin separating sheets, lowering process-air temperature ahead of downstream conditioning. It is a core element of the heat-transfer system's air-cooling capability. Service degradation includes internal and external fouling, corrosion, fin erosion, and clogging that reduces effectiveness and increases pressure drop. The dominant failure mode is cracking or pinhole leakage at brazed joints from thermal cycling and fatigue, driving leak testing, core repair, cleaning, and restoration of rated thermal performance.

Aircraft Application

Part number 790298-4 (Heat Exchanger) is installed on the Cessna Citation III. QTC supports operators and MROs servicing this platform with certified repair and overhaul.

Our Repair Capability

QTC repairs and overhauls 790298-4 to the original manufacturer's specifications under our FAA and EASA Part 145 approvals. Our team — including former OEM heat transfer 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.

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Related Parts

Other heat exchanger part numbers we repair — view all Heat Exchanger parts →

Frequently Asked Questions