The torque link stop lugs are more important than you would think. Overextension of the nose strut due to a worn out stop lug can lead to a cascade of problems. McFarlane A&P mechanics have seen struts over extend to the point where the metering pin comes out of the orifice. This results in loss of damping action and the pin hammering the orifice every landing and distorting and enlarging it. Over time, the excess nose strut travel and lack of damping can result in fatigue cracks in the torque link arms. McFarlane recommends thoroughly inspecting all nose strut components when replacing a severely worn stop lug.

The stop lug also acts as a centering device aligning the nose wheel and wheel pant straight with the airplane and slip stream after it has left the runway. Worn stop lugs can allow the nose wheel to lock in a turned position in flight that will require holding rudder for coordinated flight. Retractable gear aircraft depend on the stop lug to properly center the nose gear steering before it retracts into the wheel well.

Whenever fuel is poured, pumped or moved from one container to another, a static charge is generated. The same principle is in effect when you walk across a carpet in the winter and get a shock from a doorknob. The charge level and the distance that can be jumped or arced depends on several factors—pump rate, temperature, humidity and containers. 

Static electricity is the reason why a ground wire is always connected to commercial airliners and transport trucks whenever fuel is being transferred. When you transfer fuel into your car or light aircraft, the hose has a built-in ground wire that acts as an electrical path to dissipate any static charge. As an added precaution, there is usually an excessively rich air/fuel ratio in the fill pipe which will not burn. There are two primary areas where a pilot should exercise caution when transferring fuel. 

First is draining an aircraft tank. For example, if you’re draining a wing tank, you should always connect a jumper cable from the plane to the fuel container.  This will dissipate the charge and eliminate the chance of a spark jumping from plane to container, causing a fire. Remember, when you’re draining fuel, there can be enough air circulation so that the air/fuel ratio is in the burnable range.

The second area of concern is the filling process. Many FBOs use a ground wire when filling an aircraft.  But in some cases, fuel is transferred from a drum or can into an aircraft. Here, a jumper wire is a good safety precaution to ensure that the charge is dissipated. If you use a metal funnel with metal cans, make sure that the can, funnel and plane are always touching during transfer. 

With metal containers, the electrical charge is dissipated to the conductive container where it can be discharged by a ground wire or contact. In plastic containers, there is no good electrically-conductive path to dissipate the charge. Although some people put metal strips into the plastic container, I would recommend the use of metal containers with a good jumper wire. It's the safer way to go.

First, if you’re “breaking in” your engine on mineral oil during the winter, always take extra precautions to ensure that the engine is properly preheated prior to flight.  For example, if your service bulletins recommend preheating the engine whenever the temperature is below 20°F, you may want to increase that to 30-35°F when using straight mineral oil. 

Another concern is that mineral oil is more prone to oil cooler plugging at low temperatures.  This is especially critical on aircraft used for high altitude flight where temperatures are even lower.  If an aircraft is going to be broken in during the winter or at high altitudes, you should consider using a winterization kit.  The kit will reduce airflow through the oil cooler and reduce the chance of oil cooler freeze-up.  (However, be sure to remove the winterization kit when it’s no longer needed.) 

During winter break-in and high altitude flight, pilots should also be especially observant of their oil temperature and pressure.  If the oil pressure or oil temperature moves significantly up or down in flight, you may be experiencing oil cooler plugging or bypassing.  If this occurs, you should take appropriate action.

There is no loss of performance for the listed applicable model propellers. We have seen some performance degradation on exotic high performance experimental applications where extreme prop speeds or extra wide propeller blades were involved. We have also seen some experimental use of PROP GUARD where there were performance increases when the PROP GUARD edge was pinked on the face (forward side) of the propeller. The zig-zag pattern of the pinked edge produces a vortices generation that helps hold the moving air to the propeller surface longer.

Yes, this is an anti-corrosion material that can be used on aviation as well as automotive applications. 

Wheel pant mounting plates commonly crack around the axle. If any cracks are present, they should be replaced. The cracks are caused by wheel pant vibration. Assure that the wheel pant axle bolts are tight. Proper wheel balance will lessen wheel pant vibration. McFarlane's wheel balancers can help solve this problem.

Installation of the McFarlane Seat Stop P/N MC0511242-1 may require the removal of extra material from the seat rail where the seat rail hole breaks through the vertical web. Material removal may be accomplished with a small file or other deburring tool. Do not remove material from the seat stop when attempting to install. Refer to Cessna/Textron service information for correct seat stop location.

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.

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

P/N MCSK100 Flap Roller Service Kit replaces the aft wide roller assembly, and only the aft wide roller. Please consult your applicable Service/Maintenance Manual and Illustrated Parts Catalog for the proper location for your specific aircraft, and the STC SA01074WI.

McFarlane uses a laser to score the Bi-Flex Cowl Saver material to approximately 40% of the strip width. This works well for assuring a great air seal when you have straight or minor cowl shape changes. However, where you have a curved baffle and cowl, you will get a better fit by cutting out curved pieces of Cowl Saver from a flat sheet and then custom scoring the Teflon on the outer edges for the flexibility you need. You can score Cowl Saver with a sharp razor blade or knife. The TOOL120 scoring tool makes several scores at once and is designed to prevent cutting too deep and damaging the fiberglass reinforcing in the center of the material. The job will go much faster with use of the tool. Even with the pre-scored Bi-Flex, you may find situations where some additional flexibility by custom scoring is helpful for the best possible fit. For more information, please read Customized Flexibility for Optimal Cooling.

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.

1. A correctly functioning pump creates a vacuum in the system lines, so when the pump fails (due to wear or from FOD which has entered pump) the carbon rotor and vanes break into very fine pieces which can be sucked back up into the inlet hose. It is very important to remove the inlet and outlet hoses from the aircraft and clean them out thoroughly, making sure to remove all particles. It is imperative to clean the entire system after a pump failure. By doing so you will eliminate the chance of premature failure by your new replacement pump as a result of carbon FOD from a previously failed pump entering your new system.
2. After you have installed the new replacement pump, check and make sure the aircraft vacuum system is working properly. A faulty regulator , dirty vacuum pump filter, or a crimped or partially collapsed hose which causes a restriction in the system can force to pump to work harder, causing premature failure.
   
   
3. If your aircraft engine has high time, go ahead and replace the oil seal in the engine case where the pump mounts. The area could be dry now, but the seal could start leaking in just a few hours causing oil contamination in your vacuum pump, making it inoperable. Less than $10 dollars spent here could save you hundreds of dollars later.

Yes, but there are some restrictions. The screws must be structural screw with a minimum tensile strength of 50ksi. See SAIB CE-90-03R2 for more details.

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.

The most common indication of external fuel valve leaks is the smell of avgas in the cabin. Most valves are located under the cabin floor. Fuel stain on the valve and drain plug or drain valve or on the belly of the aircraft can also indicate external leakage. External leaks are generally around the actuation valve stem. Internal leaks are detected when the fuel is turned off and fuel continues to drip during fuel system maintenance. Inner port leakage will allow fuel from one tank to leak into another fuel tank. This type leak is difficult to detect. Fuel transfer from one tank to another with the fuel valve selected to one tank only will indicate inner-port leakage. An extended period of time is needed to detect fuel transfer from one tank to another. Generally if internal leakage is detected when servicing the fuel system, it is likely there is also inner-port leakage. 

No. As with any battery being charged it is best not to do this in the event of a faulty charger. Follow these safety tip for charging ANY type of battery.

• Never leave the battery or the vehicle unattended when recharging it.
• When charging a battery, place it on a non-flammable, and remove any flammable items nearby.
• Unplug chargers from the battery or vehicle always after the battery reaches full charge.
• Disconnect chargers when not in use.

The short answer is no. While we recommend using our taller oil filters when you have the space inside your cowling, using our shorter filters will still provide more than enough filtration coverage when replacing them at the recommended intervals of 25 to 50 hours.