Magneto Failure Overview

Magneto Failure Overview

Magneto technology is some of the oldest and most trusted in the aviation industry!
However, what happens when a pilot has magneto failure? When one magneto fails, there are a few things a pilot might notice. First, there will be a decrease in engine power, but the engine will remain running thanks to the second system being independent of the first. Second, sometimes a magneto can malfunction in its failure to ignite the spark plugs, or the internal timing may malfunction. In this instance, the pilot will notice the engine beginning to run rough and will need to switch to the remaining magneto and see if that clears the problem. 
Even though an engine will continue to run with the loss of one magneto, there are several problems with having a magneto failure mid-flight. With the loss of one magneto comes the security of redundancy. They are a vital piece of equipment, and there is a reason that aircraft are built with two. Additionally, the loss of engine power can be potentially problematic, though in most cases does not pose a serious threat to the safety of pilots and guests. 

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Even in the case of magneto failure, only a very few accidents are a direct result of magneto failure, according to statistics provided by the National Transportation Safety Board. NRSB reports 16 recorded cases of aviation accidents due to magneto failure, with two of those sixteen being fatal. Most of these failures were listed as being caused by lack of maintenance or non-compliance with servicing and inspections. 
With attention to detail and a history of reliability, Kelly Aero has made sure that the magnetos produced to be dependable and safe. Our products are designed and engineered using in-house resources, with additional tooling and manufacturing for aftermarket magnetos occurring at our facilities. We offer an FAA and PMA approved quality system, which is readily available with low wait times. We both meet and exceed the standard industry testing with our own set of criteria for the product, whether it be the full system or a replacement part. We want to work with customers to ensure the delivery of a product that is first and foremost high quality and reliable, and that meets their needs.

Aircraft-Magnetos
Quality Upgrades at Kelly Aero

Quality Upgrades at Kelly Aero

One of the great additions to our processes in 2020 is a high power AmScope Microscope to our final inspection process.
This allows every our inspection team to get take a high power look at our finished units before they leave our facility.

Our new 80 power microscope allows us to inspect our block components for carbon tracking, carbon particles can collect in small cracks and develop into problems down the road.

“The Kelly Aerospace Quality Team is committed to adding new technologies to our final inspection process,” says Neil Clark (VP Sales & Marketing) “This addition allows us to go one step further in catching minor imperfections before they leave our facility.”

Doubling down our commitment to quality, this addition allows for a 99.9% rating on all blocks that leaving our facility free of imperfections.
Our engineering and development team has made major strides over the last few years to ensure that our processes at Kelly Aerospace continue to improve.

500hr Magneto Inspection/Overhaul

500hr Magneto Inspection/Overhaul

So your prized aircraft is down for an annual and your A&P says it’s time for your 500hr inspection.
Some pilots choose to overlook the importance of the inspection.
However, the 500-hour inspection is the single most important magneto service event.

Whether you are an owner, flight school, commercial operator, or engine overhaul shop, you can ensure continuing trouble-free and safe service of an aircraft magneto.

The 500-hour magneto inspection is critical to the safe operation of magnetos. While not a required service action as an airworthiness directive, it is considered critical and
mandatory by magneto OEM’s and is considered a good, common-sense maintenance practice by aircraft mechanics.

The 500 hour is scheduled preventative maintenance and to avoid expensive unscheduled maintenance. If a magneto is not inspected every 500 hours, then the risk of an unplanned component failure that can cause inconvenient and unplanned maintenance at a location far from an aircraft owner’s home airport is certain to occur.
The cost of one or more nights of hotel, car rental, meals, missed work, lost flight revenue will easily be offset by the relatively small cost of a 500-hour inspection.
The inspection is not limited to magnetos which have accumulated 500 hours in service. A 500
hour inspection can be accomplished at any hours of magneto total time in service. In some cases, some magneto and engine combinations may result in the need to perform magneto maintenance more frequently than 500 hours. Pressurized magnetos used on Continental and Lycoming engines operate in demanding, high altitude environments and require more maintenance than other types of magnetos.
Dual contact, or retard breaker magnetos that use the Shower of Sparks starting system typically require more frequent maintenance. Magnetos used in Shower of Spark applications require frequent
inspections to ensure that fuel-injected Lycoming and Continental engines do not experience hard
starting problems.


To begin the 500-hour inspection process, an inspection return form is downloaded from the Kelly Aerospace website. Complete one form for each magneto that is returned. Before boxing the magneto, remove the drive gears attached to the magneto. Return the complete magneto, with the drive gears removed, and do not forget to include the completed 500-hour inspection form. The magneto is returned directly to Kelly Aerospace, 1400 East South Blvd, Montgomery, AL 36116 with Attn
500-hour inspection marked on the box.
When the magneto is received, work starts within 24 hours of receipt. Plan for four working days to complete the inspection, plus shipping time to return to the customer. Kelly Aerospace ships via UPS or
FedEx and can ship worldwide. Check your shipper delivery zone time chart to determine the duration of shipping time to and from Montgomery AL.
The magneto is disassembled by a magneto technician so that the parts can be inspected and cleaned.
The magneto parts are cleaned and polished as needed. Magneto frames and housings are not repainted but can be repainted if the magneto is upgraded to an overhaul. The magneto parts are
inspected by visual and non-destructive testing, and must meet the criteria established in the Bendix
and Slick Maintenance and Overhaul manuals.
The 500-hour inspection for Bendix magnetos includes new replacement hardware, new contact points,
oil slinger, oil seal, (2) ball bearings, carbon brush, o-ring, felt strip, felt washer, and impulse coupling spring. The 500-hour inspection for the Slick magnetos includes new replacement hardware, new
contact points, and cam, oil seal, (2) ball bearings, carbon brush, distributor gear to comply with

Champion Slick Service Bulletin SB1-15A and impulse coupling spring. An FAA Form 8130 will be provided to document the 500-hour inspection.
Depending upon the condition and service history of the magneto, extra work or parts may be required.
Some of the extra parts would include worn distributor gear, worn distributor block, faulty coil, faulty
capacitor, worn impulse coupling, worn rotor shaft, or parts affected by airworthiness directives.
If any other parts are required, the customer will be contacted for additional charge approval prior to work
being completed.