Royco 602 Synthetic Base Fluid for Modern Aircraft

The advent of the ‘glass cockpit’ forever changed the landscape of air travel, air navigation, and military aircraft operations. Advanced avionics changed everything, radically increasing safety and making flying safer and better overall. But those systems take a lot of energy and get hot, so advanced techniques and coolants had to be built to accommodate them. 

Royco 602 is a synthetic-based fluid that is MIL PRF 87252 compliant and built for electronics cooling systems and high-powered transmitter equipment. It is a stable synthetic hydrocarbon fluid for aircraft avionics and power supplies, and Greenwood Aerospace is a top supplier. 

What are Synthetic Base Fluids?

In aviation and defense applications, synthetic base fluids maintain a significant advantage over conventional fluids. Royco 602 is a high-performance synthetic fluid composed of polyalphaolefin (PAO), a type of synthetic hydrocarbon known for its stability, low toxicity, and excellent thermal properties. 

POAs are branched and compact molecules, which gives them superior oxidative stability and low volatility. Low volatility is always important, and having cleaner operating systems for electronic cooling systems is a major win. Synthetic base fluids tend to run cleaner over time and lend to longer component life. 

Royco 602 is tailor-made and task-suited for use in dielectric cooling systems to promote longer component life as a fluid for aircraft avionics. It is made to carry massive heat away from the avionics suite, radar systems, power supply units, computer processors, etc. It provides exceptional performance with modern technology additives.

Technical Specs and Compliance

Royco 602 is a military-grade (MIL PRF 87252) dielectric cooling fluid for aircraft avionics systems. It is also used on high-powered transmitter equipment where stable synthetic hydrocarbon fluids are required to safely transfer heat away from the source and dissipate it. 

Not only does it meet MIL PRF, but Royco 602 is assigned NATO Code S-1748, which allows for quick and easy standardization across American and Allied military inventories worldwide. Comprehensive product documentation supports it. 

Here is a quick summary of the Royco 602 Product Data Sheet:

Product Data Sheet (PDS) Highlights


Royco 602 is a synthetic PAO-based dielectric coolant for aircraft avionics, high-powered transmitters, power supplies, radar, navigation, and electronics cooling systems.

  • Base Fluid: Polyalphaolefin (PAO) with modern additives
  • Operating Temperature Range: -54°C to 200°C
  • Key Properties:
    • Kinematic viscosity @ 40°C: 5.18–5.19 cSt
    • Kinematic viscosity @ 100°C: 1.72 cSt
    • Pour point: -100°F (-73°C)
    • Flash point: 158°C
    • Fire point: 173–175°C
    • Viscosity index: 145
    • Water content: <30 ppm
    • Dielectric constant: 2.10
    • Dielectric breakdown voltage: 53 kV
    • Volume resistivity: 2.43 × 10¹¹ ohm-cm
    • Acid number: <0.01–0.03 mg KOH/g
  • Benefits:
    • Doesn’t react with water (hydrolytically stable)
    • Lower toxicity and environmental impact
    • Longer fluid life, lighter, and lower cost than many other avionic coolants
  • Elastomer Compatibility:
    • Recommended: Nitrile (N 674-70), fluorosilicone, fluorocarbon (PTFE, Viton), polyacrylate
    • Not recommended: Ethylene propylene, Buna N, SBR, polychloroprene, neoprene, natural rubber
  • Approvals: Qualified to MIL-PRF-87252

Performance and Benefits

Royco 602 has a wide temperature operating range and is made to promote cleaner operating systems throughout the entire avionics suite of the aircraft. Unlike older dielectric fluids, such as the extremely caustic Coolenol, Royco 602 is a hydrocarbon known as polyalphaolefin, which is much less toxic. 

Also, it is a much lighter fluid than other comparable dielectric fluids, helping military aircraft maintain efficiency and saving weight for more important items, like fuel and munitions. 

It works well across a wide temperature range, offers exceptional performance, and supports many ordnance systems that require reliable avionics suites for accurate delivery. 

Industry Use

Royco 602 can be used in industrial applications, unlike other fluids and lubricants used in aviation. Although Royco 602 is mostly aviation-specific, industrial high-powered transmitter equipment in non-aviation uses that need dielectric cooling fluid with a stable synthetic hydrocarbon base with low toxicity could conceivably exist. 

Ground radar systems are one mission where non-aircraft use comes into play, which produces enormous amounts of heat. Also, command and control computer systems that use circulating coolant systems can use Royco 602 if authorized for MIL-PRF-87252. Thanks to far lower toxicity levels than other dielectric fluids, it does not require nearly as much specialized reclamation equipment. 

Procuring Royco 602 through Greenwood Aerospace

Greenwood Aerospace is your go-to for all of your government procurement needs. We can source and catalog hundreds of oils, lubricants, and sealants. The odds are good that we have what you need; if we don’t, we can get it. 

We supply Royco 602 dielectric cooling fluid in 5-gallon buckets for your maintenance operations. When you need PAO stocked up, this is the way to go, so call us at (580) 762-2580 or start an online quote.