Miscellaneous

Will my oil temperature be higher or lower with a multigrade?

In most cases, the multigrade oil will run cooler. For a hot-running engine, like turbocharged, high performance or aerobatic aircraft engines, this is good, but for a cool-running engine it can be a disadvantage. If the engine runs too cool, it can't boil off excess moisture and unburned fuel, so there can be a tendency to form acid buildup. For cooler-running engines, pilots should use a winterizing kit, or check with their mechanics on how to keep oil temperature up.

Will oil temperature affect the oil pressure in an aircraft engine?

Yes. The thickness, or viscosity, of an oil is directly affected by the temperature. Therefore, if an engine's oil temperature is increased, there will be a small, but proportional, drop in the oil pressure as well.

Will the synthetic portion of semi-synthetic AeroShell Oil W 15W-50 harm an aircraft engine?

A number of pilots have asked this question. The answer is a definite no. When Shell first started evaluating multigrade aviation piston-engine oils over 25 years ago, testing proved that multigrades formulated only with mineral base oils did not have adequate base oil viscosity (thickness) to properly lubricate all high load points in the engine. Then we tested and flight evaluated a formulation made with all-synthetic base oils.

This formulation had excellent antiwear characteristics in all tests run. However, in the flight evaluations, some engines would reach 600 to 900 hours, then lose oil consumption control and/or compression. When the engines were disassembled, we found that the piston rings were covered with a gray tacky substance that was primarily made up of the lead by-products of combustion (from the use of leaded aviation gasoline).

Although synthetics are excellent lubricants with good high temperature stability and very good low temperature flow characteristics, they are relatively poor solvents.

In an aircraft engine, the lead by-products of combustion must be dissolved by the base oil so they can be carried away from the ring belt area and removed from the engine when the oil is changed. Anticorrosion, antiwear AeroShell Oil W 15W-50 is formulated with 50% synthetic base oils to give it the excellent low temperature flow needed for quick lubrication during cold starting. 

The synthetic base oils, along with the unique antiwear additive system, give it antiwear protection unequaled by any other product on the market. In addition, its mineral base oils provide lead absorbency to guard against ring sticking and excessive sludge. The bottom line: The synthetic component of AeroShell Oil W 15W-50 will not harm your engine. Instead, it gives you the best of both oils.

All other anti-seize I have used are thick. How can this work when it is so thin?

The D A M high temperature anti-seize formula is based on inert high temperature dry lubricants suspended in a naptha carrier with a few other low viscosity additives. The thick grease base in other anti-seize products on the market burn and char at exhaust temperatures leaving sticky hard deposits that actually contribute to the lock-up of exhaust joints. The D A M product carrier evaporates leaving only a film of dry lubricants in the joints that penetrates the pores of the stainless steel. 

How does the D A M product work to loosen locked slip joints?

D A M’s light petroleum carrier uses capillary action to penetrate the joint and carry the small particles of dry lubricant into the joint.  By mixing D A M and other solvents such as acetone, MEK or other solvents the viscosity is lowered more yet and the mixture will penetrate small spaces more effectively to loosen corrosion and combustion by products while lubricating the joint.

How is the D A M product different than other anti-seize products?

D A M anti-seize works on the principle of very small particles of inert dry lubricants imbedding themselves into the open pores of the stainless steel. The dry lubricants lowers friction and prevent corrosive adhesion of the two stainless steel surfaces. The dry lubricants prevent combustion by products from actually gripping the stainless steel. Other products rely on powdered metal such as copper or nickel in a mix of greases and graphite. The powdered metals themselves are often corrosive to the stainless steel at high temperatures and actually create adhesion by microscopic corrosive residue. The old failed theory is that the metal powder flakes will separate from each other and allow disassembly. This does not work at high temperatures and with stainless steel.  Any graphite in the compound (graphite is required for MIL SPEC anti-seize compounds) sets up a severe galvanic corrosion action with the stainless steel and the powdered metals that produces corrosive by products that swell and lock the joint while attacking the grain structure of the stainless steel. This corrosive action is accelerated at high temperatures and contact with combustion by products.    

Is there anything I can do to make D A M work better?

Since D A M is a mixture of heavy dry lubricants and light petroleum distillates, it will separate quickly.  Shaking the can often during use keeps the lubricants in suspension. D A M works best when it is rubbed into the stainless steel. Rotation joints back and forth before final assembly will help imbed the dry lubricant particles into the stainless steel surface. Then disassemble and recoat the joint.

It is in a small can. Will it do very many exhaust joints?

 Only a thin film is required to be on the surface of both parts of the exhaust joint so the small can will service many more exhaust joints compared to a big can of pasty grease. 

Why does a small can of the D A M product cost so much?

The high temperature inert dry lubricants are expensive to produce and refine. Since it only takes a thin film to be effective it is more economical than other anti-seize compounds. A can goes much further.

Does D A M window cleaner have anything in it that will hurt my windows?

No, D A M does not have any ammonia or other strong chemicals that could attack or shorten the life of any plastic. D A M has a very small amount of alcohol (less than .3%) in a water based solution. The quantity is so small that it has no effect on plastic or other surfaces. D A M is safe on all surfaces.

How does D A M protect my windows from dust and dirt scratches while cleaning?

The polymers and carnauba wax in D A M window cleaner lubricate and encapsulate the abrasive dust and dirt particles so they slide on the plastic surface until they are absorbed deep into the wipe-off towel. The dust and dirt particles are still there, but they cannot get a damaging grip on the plastic surface. After the D A M cleaner is polished off it leaves a protective film that also helps prevent abrasion penetration of dust and dirt particles.

Never wipe a plastic surface when it is dry (or extensively while wet with just water) as some of the abrasive particles will be gouged into the surface, causing scratches.

Is D A M window cleaner toxic?

D A M window cleaner is a mixture of non-toxic wax, polymers, and a mild detergent with the slightest trace of alcohol. It is an irritant to the eyes if it has direct contact.  

What is the best cloth to use on an aircraft window?

There are two types of cloth that work well to prevent scratching on plastics.

The first is the synthetic micro fiber cloth. This soft supple fine matrix cloth will do an excellent job of protecting the acrylic surfaces. The down side of this cloth is that it is expensive and the wax and polymers used in plastic cleaners do not wash out well. The microfiber cloth will have to be thrown away when the wax and dirt buildup prevents a streak free surface.

The other cloth that works well is soft cotton cloth, with the best construction being T-shirt material. The fluffed soft cotton fibers have layers that isolate dust and dirt well from the cloth surface and they can be used many times. The cost is low enough that you can just throw them away when they get contaminated.

Why do the D A M window cleaner instructions say to use my hand to scrub the window?

Scrubbing the window with your hand is most effective as the cleaner is not being absorbed by a rag. This process gives the cleaner time to soak into the bugs and dirt while distributing the cleaner evenly. A very small rag wet with the cleaner or a VERY SOFT bristle brush also works well. Wash your hands after you are done.

Why not use paper towels on my aircraft windshield? They seem to work great!

Aircraft windshields and windows are made from a hard durable MIL standard acrylic plastic that has a long service life. However, they are still plastic and can be damaged if not cleaned properly. Aircraft windshields and windows are not only expensive, but changing them takes a lot of expensive labor. Paper towels are made from a matrix of processed wood fibers that can be hard enough to scratch plastic. Paper towels will not damage the acrylic every time they are used, but consistently using them will eventually give you little fine scratch defects that refract light differently than an adjacent smooth surface. The small differences in light refraction will obstruct and distort your view.  

Dust is made up of many little abrasive particles so it is important to isolate the dust particles from the windshield as you wipe. The softer and more expanded the cloth material is, the greater the tendency for the cloth to absorb the dust particles isolating them from the cloth surface. In other words, the dust particles can go deeper into a soft fiber matrix as compared to a harsh hard fiber matrix of paper towels. Dust and dirt particles tend to collect on the hard paper towel surface giving it a sandpaper effect. Gently feel a paper towel surface. Gently feel a T-shirt or micro fiber cloth. The surface hardness is very noticeable. 

In summary, there are really two differences in a paper towel and a soft fiber cloth. One difference is the hardness of the actual fiber and the second is the ability of the fiber matrix to absorb dust particles away from the fiber surface. 

My Cessna 180/182/185 stabilizer trim is hard to turn or jams. How do I fix it?

Clean the barrel and screw jack and re-apply a coating of MIL-PRF-23827 low temperature grease. The cam bushings that attach the jack screws must be properly adjusted so that both jack screw work as one unit. If the cam bushings are not adjusted correctly the jack screws can work against themselves causing a hard to turn situation. Please review the complete instructions.

My Cessna 180/182/185 trim wheel will sometimes rotates out of position in flight, changing my trim setting. How can I fix this?

The trim wheels on the Cessna 180, early 182 and 185 aircraft have a spring loaded trim wheel stop catch assembly that engages with a molded in ratchet on one side of the trim wheel. This system is designed to prevent unwanted trim wheel movement caused by air pressure on the horizontal stabilizer. If these stop catch assemblies are worn out, the trim wheel is free to rotate. McFarlane has replacement stop catch assemblies.

What hardware is used for installation?

Our Vertical Fin Fitting kits include all the hardware needed for installation. You may receive NAS1149 hardware with the kit, which supersedes AN960 hardware (referenced in our ICA).