How Royco 481 Mineral Oil Jet Turbine Oil Extends the Life of Aircraft Engines

Jet engines are one of the truest modern marvels of our age. They single-handedly took world travel from weeks, months, or years, to hours and minutes. A voyage from San Francisco to Tokyo that once took weeks, even on a steamer, is now less than a day in a jet airliner. 

Jets also allow airplanes to operate at much higher altitudes and much higher cruising airspeeds with greater reliability and far higher payloads than the most significant piston engines ever produced. How stark is the contract? A CFM56 weighs slightly more (~4,300–5,600 lbs (1,950–2,540 kg), depending on variant) than the Pratt & Whitney R-4360 Wasp Major, which was one of the largest piston engines ever made, yet the CFM56 produces roughly ten times the power. Not only are they far more powerful, but they do so with far fewer moving parts. 

However, the moving parts of a jet engine are under tremendous load, so oil is absolutely critical. Royco 481 is a market-leading mineral-based jet turbine engine oil, and Greenwood Aerospace is a proud supplier. Let’s take a look at this high-quality oil.

What is MIL-PRF-6081?

First and foremost, is Royco 481 approved for military use? Yes! It definitely is. However, as with all industrial lubricants, they must meet a Military Performance rating to be certified for use. The rating that Royco 481 falls under is MIL-PRF-6081, which is currently in its fifth revision, or “E.” The MIL-PRF is a document that details all of the physical and chemical characteristics that must be met. Several manufacturers make MIL-PRF-6081 compliant oils, and Royco Lubricants' model is Royco 481. 

What Is Royco 481 and Why Does It Matter?

Royco 481 is the commercial variant of a standard mineral-based jet turbine oil. This oil is commonly used in several aircraft, although the specifics are located in the technical specs for each engine in the inventory. 

Royco  481 is used not only in turbine engines but also in their small cousins, Auxiliary Power Units (which are just small turbine engines). Also, Royco 481 can be found in turbine start carts, a stationary piece of ground support equipment that uses a small turbine engine (very similar to an APU) to provide bleed air for jet engine starts.

Basically, any application of jet turbine oil that calls for MIL-PRF-6081 is an ideal candidate for Royco 481 turbine oil.

The High Cost of Corrosion in Aviation

Corrosion is the silent killer of all things aviation, which is why the DoD goes to extensive measures to make sure that corrosion is kept to a bare minimum, which explains the extreme longevity that U.S. military aircraft are afforded. We regularly see aircraft that are pushing 70 years of age.

We routinely consider corrosion on the outside, or structure, of the aircraft, which is inhibited by routine cleaning and washing. But corrosion is also destructive to the internal components, and engines are absolutely susceptible to corrosion internally. 

Royco 481 is formulated with modern additives (recall that mineral-based oils are generally used on older generations of engines) to provide protection from oxidation and corrosion, plus it is highly viscous. When internal engine components rotate at several thousand RPM in all environmental conditions, viscosity is important to overall engine health. 

Royco 481 has employed an ashless additive compound formulated to prevent deposits in the oil supply at high temperatures. In addition to MIL-PRF-6081, Royco 481 is also approved by MIL-PRF-2073-1C as a corrosion preventative compound for gas turbine engines.    

How Royco 481 Protects Aircraft Engines

The base oil for Royco 481 is mineral oil, which is still called for in many legacy engine systems (modern engines are predominantly synthetic blends), but it has been largely modernized with modern additives. It is a high-quality corrosion inhibitor and an approved preservative for long-term storage and preservation of engines. So, when legacy engines are put into storage, they can be serviced with Royco 481 and remain serviced for an extended period. 

Also, it is an approved flushing agent, which means that when a component fails within an engine or component that necessitates flushing the system, Royco 481 is approved and will do a good job of picking up particulates and shavings. Generally, a hand cart is hooked up, and oil is pumped through the reservoir and system until it comes out shaving-free and contaminant-free. 

Benefits of Using Royco 481

There are increasingly fewer available options for MIL-PRF-6081-approved oils because the market is moving on to synthetic-based oils that modern designs call for. However, the U.S. military still operates hundreds of legacy engines with the B-52 fleet (eight engines per operational jet plus spares), the E-3 AWACS fleet, and the E-8 JSTARS fleet (for however long they have left). 

Engines and other system components that call for mineral-based oils must use one that meets the criteria set out in MIL-PRF-6081 (whichever revision is the latest, currently “E”); any modern synthetics that are a different MIL-PRF can and will damage the engine. 

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Where to Buy Royco 481 for Government and Commercial Aviation

Greenwood Aerospace is an approved vendor of Royco 481 jet turbine engine oil, and we currently carry it in both a five-gallon bucket and 55-gallon drums to meet whatever scale and level of demand you have for this product. 

Greenwood Aerospace Is Your #1 Supplier of MIL-PRF-6081 Turbine Oils

We have focused on Royco 481 in this article, but that is not the only MIL-PRF-6081 oil Greenwood Aerospace carries. We also supply Brayco 460 jet lubricating oil, currently in 55-gallon drums. This meets the exact specifications as Royco 481, so check out our prices on both! Our goal is to provide not only the most competitive price points on these lubricating oils for you, but to do it at the best price point. 

Ready to get started? Call us at (580) 762-2580, email us at contact@governmentprocurement.com, or start an online quote here!