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.

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.

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.

We understand the fear of a fire in an aircraft is real and justified. We also understand people fear that a lithium battery will spontaneously self-combust with no warning and reason and catch everything near it on fire too.  We want to address this fear. The EarthX batteries are LFP chemistry, or lithium iron phosphate, the most abuse tolerant and requires a lot of energy to force them into thermal runaway. The term thermal runaway can mean different things and for a LFP battery, it does not mean a 3-foot-tall explosion of flames, it means it will produce a lot of smoke for about 10 minutes.  (It should be noted the type of chemistry that does cause a large fire ball is the most used cell in the world, a Lithium Cobalt cell. This is found in your cell phone, your tablet, your laptop, etc.  On a commercial flight, if you are traveling on a 737 with 204 person capacity, it would be typical to have around 300 of these batteries in the cabin with you as a reference point).

To cause a thermal runaway with the EarthX battery, many things in your aircraft, and you as a pilot, would have failed. First, your regulator would have to fail. Then your over voltage protection on your aircraft would have to fail. Then you as a pilot would have to fail and not turn your charging system off (alternator off) as you see the voltage and amps climb, destroying all your electronics on your panel and popping fuses everywhere in the process. If you did nothing but continued to fly, and if the batteries protection failed too or you exceeded the protection limits (over 100V), it takes about 7 minutes of this type of runaway energy to cause a thermal runaway with the battery. The FAA TSO certified approved battery, the ETX900-TSO,and the ETX900-VNT, are in a fireproof containment system (internally) and is a sealed battery that is vented overboard, so even in this catastrophic state, the smoke is pushed overboard and it is not a battery safety issue and it does not cause anything near it to heat or catch on fire either.  

As far as the fear of spontaneous self-combustion, the battery must be part of a catalyst situation for it to go into thermal runaway. It will not simply “combust” with no reactor.  The batteries have short circuit protection and a battery management system to prevent the use of the battery if it detects a fault. The Hundred series for aircraft also has a fault monitoring that would alert you if something was outside of normal with an LED light that will illuminate.  

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. 

Lightweight starters do not have as much housing bulk surrounding them, so they aren’t as effective at insulating the gear train noise from the operator. To compound the issue, switching from a legacy heavyweight starter to a lightweight starter may also change the design style from a direct drive to a gear reduction drive in order to obtain the same drive torque. Gear-reduced starters have a much different noise signature than direct drive starters.

It appears that Superior reverse engineered the 60882-type ring gear support assembly (for 122-tooth ring gears) when they manufactured and PMA certified Superior Ring Gear Support Assembly PN SL77579-1 Rev.11 (for 149-tooth ring gears). Unfortunately, when pairing those ring gear support assemblies with 149-tooth ring gears, the ring gear rests further aft than Lycoming specification and therefore tends to crash the front face of NL-type starters by a mere couple thousandths of an inch. Other starter models tend to stand back sufficiently from the ring gear, so the mismatch is not as problematic. Since the NL “hugs the line” defined by Lycoming, the mismatched ring gear and support assembly causes an interference condition.

THIS CAN BE A DANGEROUS SITUATION. The starter contactors in many older aircraft may become welded shut after years of use. BE EXTREMELY CAREFUL. A starter contactor that is welded shut could cause the propeller to rotate when the master switch is energized, regardless of the position of the start button or switch. Replace the starter contactor. Your starter may have been damaged by this as well and may also need to be overhauled or replaced.

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.

There are two potential causes of this condition. If it is a mechanical starter drive (Bendix) and sticks intermittently, it most likely needs to be lubricated. This type of starter drive is initially lubricated to allow smooth operation. The drive gear must move in and out and also rotate. In use it can become dry and may begin to stick and fail to engage or disengage. We recommend lubricating this type of starter drive every fifty (50) hours of operation.

The other likely factor for intermittent engagement would be a faulty starter contactor. If you want to check a contactor, it is best to do so with a load applied. Resistance in the contactor, even a fraction of an ohm, is enough to produce poor or no operation due to the high current field. In a 12-volt starting circuit drawing 60 amps, for example, the addition of 0.2 ohms of resistance due to an oxidized connector or carbonized contact may drop the current to the load to 36 amps. This is a 40-percent loss in starter operating power caused only by a 0.2-ohm resistance.

Checking the circuit without a load would require that a lot of resistance be placed in line. The best method of checking the contactor is to disconnect the lead from the starter and connect it to a battery load-meter tester. Activate the contactor and check the voltage on each side of the contactor. A 0.1-volt drop is normal for a new or nearly new contactor. If you find any more than 0.3-volt drop, replace it.

For Continental engines, the most likely cause is a slipping starter adapter. This requires replacement or overhaul of the starter adapter.

Many things can cause a puffy or swollen looking battery, which is caused by the buildup of gases inside the battery. This can be from age as gas will build up over time; being exposed to extreme temperatures; deeply discharging or overcharging of the battery.  This is a good indicator that it is time for a new battery.

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.

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

Use a Lycoming alternator strap and MS20074-05-06 (5/16-18 thread) bolts. 

The carbon vanes inside the pump are sticking in rotor slots. Oil or solvent has entered the pump either from a bad oil seal in the engine case at the pump mounting area, or from pressure washing the engine with an oil-based solvent (spraying directly on the pump). The oil or solvent will work its way up into the pump through the drive end, mixing with graphite dust and turning into a paste like material.

A Dry Air Pump is just that: DRY. As the carbon rotor and vanes wear, they produce graphite dust which lubricates moving internal parts of the pump. When oil or solvent mixes with this graphite dust, it keeps vanes from moving freely in their slots and they stick. At low engine RPM, the vanes are recessed in their slots and create no vacuum, but as engine RPM increases, centrifugal force slings the vanes out, allowing them to grab air and create vacuum. Once a pump has become contaminated, its life expectancy is extremely short. The cause of pump contamination should be determined and corrected and the pump should be replaced as soon as possible. 

Yes. This can be very difficult on some aircraft, but it is recommended. The reason for changing oil when the engine is hot is to avoid the settling of dirt and water in a cold engine. When the engine is fully warmed, then drained, a higher percentage of contaminants are drained away with the old oil. When the engine is drained cold, more of these contaminants remain in the oil in the bottom of the pan, which results in more contaminants mixing with the new oil.

In some cases, engine kickback will fracture starter drive gears. Kickback is related to engine set up and can be anything from incorrect timing to problems with the fuel system. If kickback is noticed as a common occurrence on the airplane, diagnose and repair the problem or the replaced starter drive may fracture again. Many of Sky-tec's current starters offer kickback protection.

This condition is related to the starter drive extension and retraction and affects all styles of starters. If, during normal extension, the gear does not extend completely, stress will be placed on the drive gear. If the starter drive does not disengage after start, the engine will tend to drive the gear placing stress on the gear and destroying the motor. In either case, the gear will rapidly wear or fracture.

Please refer to the Tempest application chart. There are several things you will need to know as most engines have several different spark plugs approved.

1. You will need to know your harness B-nut size. This is the nut that screws onto the spark plug. It will be either a 5/8-24” or ¾-20 thread. Be aware that a 5/8-24 utilizes a 3/4” wrench and a ¾-20 utilizes a 7/8” wrench.
2. Long reach v. short reach will be determined by the specific engine.
3. Heat rating is indicated by the numeric value of the spark plug part number. The lower the numeric value the colder the heat rating. Best practice is to use the same heat rated plug you have removed.
4. Massive electrode or fine wire is a personal choice. Massive plugs will generally operate 400-500 hours. Fine wires can last 1500 hours. This choice is usually determined by number of annual hours flown and the size and performance of the specific engine.