Firewall Forward

Why does oil turn black between oil changes, and why does the time it takes to change color vary?

When a straight mineral oil turns dark or black, it usually means that the oil is starting to oxidize and needs to be changed. Because mineral oil doesn’t absorb much of the dirt and sludge in your engine, the oil stays clean and the inside of your engine gets dirty. Ashless dispersant oils, on the other hand, are designed to get dirty so that the engine will stay clean. 

Just how quickly the oil turns black depends on a number of factors, including the condition of the engine, the dirt load, the oil temperature, the normal air/fuel mixture, the type of fuel, the time since the last service, and the frequency and duration of your flights. Basically, the important thing to remember is to change your ashless dispersant oil on calendar and engine time, not according to its color. Also, oil analysis can help ensure that the oil is still in good condition even though it may have turned black.

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.

Do you need a capacitor for Plane Power alternators?

Per the manufacturer, Plane Power alternators do not include capacitors.

Are Barry Mounts sold as single side or as pairs? Are they one position per price?

They are sold in pairs and are one position per price. 

Do Barry Engine Mounts come with new bolts and washers for mounting?

No, they will only include the bushing. All mounting hardware will need to be purchased seperately.

Do the 96301-01 mount cushions come drilled and tapped for the grounding cable required at the left front and right aft mount isolators?

Yes, the hole for the grouding strap is drilled and tapped, ready for strap installation as necessary. 

When should I replace an engine mount?

Typically, you will feel unusual vibrations when you start your aircraft's engine, accompanied by loud clanking and banging from the engine bay. 

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. 

Are lithium batteries safe?

Since inception in 2009, EarthX has designed their lithium batteries with a micro-processor-controlled battery management system (BMS) to provide safety and performance features for your battery.  EarthX is not new to providing lithium iron phosphate batteries. Over the past 13 years, has become the most trusted and used lithium battery in the experimental aircraft market and by working closely with OEM’s and engine manufacturers a like, this BMS has been developed to be one of the most reliable in the industry. EarthX is not only the exclusive provider for the Indy Race Cars, but EarthX is also the first company in the world and in history to have an FAA TSO certified aircraft battery as a testament to the safety and quality of the batteries.  

Features of the BMS protection:

• Cell balancing
• Low voltage protection
• High voltage protection
• Excessive Cranking Protection (Heat)
• Short circuit protection
• In the Hundred series, an alert LED fault light to communicate an issue on battery itself or can be remotely monitored with a 12V LED
• In the Hundred series, the BMS board is redundant so there is no single point failure

Battery design safety features:

• Proprietary battery case design with recessed terminals to protect from short circuiting
• Clam shell design with terminals down the center so polarity (installation) is never an issue
• Flame retardant plastic housing
• The state of the art ceramic cell separators to reduce the risk of thermal runaway by 400% over standard lithium cell separators.

Performance design features:

• The widest operating temperature range available
• A rated cells that must meet stringent testing requirements
• True industry standards testing specifications

Can I hook an EarthX battery in parallel or series with a lead acid battery?

No, the voltages are not the same and you will over charge the lead acid battery and drain the lithium.

Can the battery be installed in any position?

Yes, lithium battery can be installed in any position for they are a dry cell technology.

How do I know if my battery charger is working?

The new fully automatic chargers on the market today need to be hooked up to a battery before they will output any voltage. This is primarily a safety feature that prevents spark when hooked up, and protects the charger against reverse polarity hookup. Some chargers need to see as much as 9V volts before they recognize that they are attached to a battery. Once the charger is hooked up, it should output 13.9-14.6 volts. If your charger does not do this, you may want to contact the manufacturer for further troubleshooting tips.

How do I know when it is time to replace my (LFP) lithium battery?

All battery types lose power and capacity as they age. The rate of when this happens depends on the maintenance of the battery and how it has been used (or abused).

• If you notice your battery just doesn’t have the same “umph” as it used to, it might be time to replace it.  In the cold this issue is more prominent.
• If you notice the battery is “swollen.” As the battery ages, gases can build up inside the battery and make the battery look bulging or swollen. The gases are not dangerous or have any safety issue, but the pressure can puff the case.
• If the battery is left in a discharged state and then very quickly charged, the cells can puff causing the case to look bulging.
• The battery will not hold a voltage above 13.28V for the 12V vehicle applications or 26.56V for 24V vehicle applications.
• The fault light is solid or flashing on the battery models that have the LED alert and is consistently on for days.