FOHE Case Study: F-15 and F-16
The Leader in FOHE Cleaning Technology
HotFlusher, based in New Hampton, Iowa, stands as a leader in the specialized cleaning and flushing of oil coolers, fuel oil heat exchangers (FOHEs), and other heat exchangers. With over 30 years of experience and a massive 500,000+ square foot facility, the company—operated by Dennis Hansen, Tyler Hansen, Jordan Nelson, and Lindsey Valentini—has developed more than 500 proprietary protocols to restore these vital components to peak performance.
Trusted by the United States military, thousands of automotive shops, and industries worldwide, Flushing Services uses its patented Hot Flush technology to remove up to 99.9% (and in some claims, 99.99%) of debris, varnish, sludge, carbon deposits, particulates, and other contaminants—often delivering results as clean as, or cleaner than, brand-new OEM units.
Expertise Across Industries
The company's expertise spans industrial, automotive, and aerospace applications. In aviation, Flushing Services has created tailored protocols for a wide range of aircraft, including historic warbirds and modern fighters.
Historic Aircraft
Dedicated cleaning procedures for rare warbirds including:
- B-29 Superfortress (only 2 airworthy examples left)
- P-51 Mustang
- P-47 Thunderbolt
- Seven additional iconic warbirds
Modern Military Fleets
Protocols cover current military aircraft:
- F-15 Eagle
- F-16 Fighting Falcon
- T-38 Talon
- F-35 Lightning II
- F/A-18 Hornet
As the only company worldwide with the specialized equipment and proprietary methods to achieve such thorough results on these complex systems, Flushing Services prevents premature failures, extends component life, and supports mission readiness.
Our Patented Hot Flush Technology
At the core of this capability is the patented Hot Flush technology, which employs:
- High-velocity, heated, pulsed reverse-flow flushing cycles (often up to 180°F and 20 GPM)
- Non-corrosive fluids combined with air injection where needed
- Precise filtration to ensure optimal results
This non-invasive process dislodges stubborn fouling without harsh chemicals or full disassembly, outperforming traditional methods such as solvents, mechanical scraping, or basic reverse flushing. The company holds multiple patents underpinning these innovations, ensuring superior efficiency, safety, and repeatability.
New protocols are developed daily to address emerging cooler designs and challenges across industries.
Case Study: Solving Thermal Disconnects in F-15 and F-16 Aircraft
The Problem
The FOHE (Fuel-Oil Heat Exchanger) in these high-performance fighters transfers heat from engine oil to fuel, cooling the oil for engine reliability while warming the fuel to prevent issues such as waxing or icing.
Over operational time—exacerbated by high-G maneuvers, extreme altitudes, and variable conditions—the FOHE accumulates contaminants, creating a "thermal disconnect" in which the system fails to dissipate heat effectively.
Consequences Include:
- Elevated oil temperatures, risking engine overheating
- Inadequate fuel cooling, leading to inefficiencies
- Degraded engine performance or safety-triggered shutdowns
- Increased maintenance downtime and costs
The Solution
Flushing Services' dedicated protocols for the F-15 and F-16 FOHE leverage Hot Flush technology to restore full thermal performance:
- Diagnostic Preparation — Initial circulation assesses fouling extent while loosening deposits
- Intensive Flushing — Pulsed, high-velocity, heated reverse-flow cycles scour internal passages, evacuating contaminants
- Verification and Protection — Post-flush testing includes flow-rate verification, pressure-drop analysis, and thermal-efficiency checks
This method minimizes downtime compared to overhauls, is non-damaging to sensitive components, and meets military standards.
Proven Impact
20-30%+
Improvements in heat-transfer efficiency
99.9%
Debris removal rate
500+
Proprietary protocols developed
30+ Years
Of industry experience
For the U.S. military and operators of F-15s and F-16s, this translates to higher mission availability and sustained air superiority or multirole capability. The process has proven particularly valuable in high-usage environments, preventing aircraft grounding due to FOHE-related thermal faults.
Our Commitment to Innovation
Flushing Services remains committed to innovation, continually refining techniques to meet evolving demands—from legacy warbirds to next-generation platforms such as the F-15EX and F-16V variants. Whether for routine maintenance or complex restorations, the company delivers unmatched results that keep critical systems performing at their best.
Ready to Experience the Hot Flush Difference?
For more information, free estimates, or to take the "challenge" (send a unit for a superior cleaning demonstration)
Call Toll-Free: 1-800-852-5713
511 Bailey Ave, New Hampton, IA 50659