The purchase of an aircraft isn’t as simple as kicking the tires and taking a test flight. Most aircraft have a significant dollar value to the buyer and seller. The value of the airplane is directly affected by the sum total of the state of repair of all of the airframe, powerplant, and a myriad of installed equipment. To verify the value of the airplane, dozens of “good-bad” assessments of the operating condition of the plane must be made. These assessments are based upon not only the physical inspection of major components but also the condition of the supporting accessory components.
Buried in the powerplant package are the magnetos. A simple observation may be to run the engine, flip the mag to left and right to see what the RPM drop is and how the engines run on the individual magnetos. If the magnetos are working, they are working, if the engine runs, it runs. Right?
Well, maybe not so simple. While the magnetos may pass a basic engine run-up inspection, there are lots of not so obvious logbook records for required maintenance which keeps the magnetos in good operating condition. New airplane owners may get hit with “catch up maintenance” to the tune of thousands of dollars if the inspection and Airworthiness Directive compliance of the magnetos require attention.
It is a certainty that various maintenance issues will be identified during the inspection. Repairs will either need to be done or inspections may be due at some point after the purchase of the plane. These issues are not likely to substantially affect the purchase price of the airplane unless particularly expensive or of negative impact on the operation of the aircraft or engine.
Ultimately, the prepurchase inspection benefits the buyer to know what maintenance requirements are upcoming for the purposes of budgeting and scheduling maintenance. If money needs to be spent after buying an airplane to correct maintenance issues, better to know this upfront. As the saying goes “better to be advised than surprised!”
LOGBOOK DIVE
The very first step is to confirm that the magnetos installed on the engine match the logbook entries. No surprise, but logbook records can be messy and entries to record installation and removal of magnetos may be incomplete.
A common scenario is that a magneto was installed in a hurry and the work was never recorded in the logs. The result is that the serial numbers of the installed magnetos actions of Airworthiness Directive compliance and 500-hour inspection in the logbook will not match the unrecorded, but installed, magneto. Verify the installed part number and serial number and then review the logs to match to required or recorded maintenance events.
Regarding maintenance events, magnetos will have some fundamental inspection points which should be recorded in the logbook:
The logbooks may have a list of Airworthiness Directive AND Service Bulletin compliance, but is the list complete and accurate? The ADs and Service Bulletins on Bendix and Slick mags are too numerous to list in this discussion and should be researched for current effectiveness (Kelly Aero ES magnetos do not have any Airworthiness Directives, so a much shorter discussion!).
Surprisingly, a complete listing for ADs for both Slick and Bendix may not be found by searching the FAA or magneto manufacturer databases. Some ADs are only found when searching on the engine model, and in some cases, the magneto AD is against the airframe (!!). Of note, one Slick Airworthiness Directive, AD 88-25-04, is applied against the airframe and requires instrument panel placards and Airframe POH amendments. A great example is that the deep dive into records may extend beyond the logbooks.
The bottom line with logbook AD records: Trust but Verify. It is likely that the previous mechanics have done the required work. But, any mechanic working on an airplane and engine new to them will need to research and review that the magnetos match the records.
CALENDAR YEAR MAINTENANCE
All magneto manufacturers require an overhaul of magnetos based on calendar time, regardless of hours. The idea is that a magneto that is not operated frequently is perhaps even more likely to experience service issues than a magneto operating 1,000 hours in one year.
Bendix has a detailed Service Bulletin SB643C that details how some Bendix magnetos are subject to either a 5-year overhaul or 12-year overhaul, depending upon the serial number and model number specifics. Both Slick and Kelly detail 12-year overhaul requirements in their manuals.
The basic idea here is that, when purchasing an airplane with a low-time engine, the date when the engine was overhauled, may have some unforeseen implications. The magnetos may have low operating hours. But, the low operating hours’ overtime may trigger manufacturer requirements for inspections that could potentially incur a substantial expense for the new owner.
THE 500 HOUR INSPECTION
The record of the 500-hour inspection may be the single most important record in the logbook. The 500-hour inspection is a routine maintenance event that can be performed at any time during the service history of the magneto. This inspection can be used to remedy Airworthiness Directive compliance and other inspection requirements if the magneto has an unclear service record. If the logbook shows no record of 500-hour inspections and the magnetos have more than 500 hours, then the inspection is due.
Consideration at the prepurchase inspection is to negotiate with the seller to complete the magneto inspection as part of the sale. Or, perhaps split the cost? It is a relatively low-cost inspection, but the benefit is that both the seller and buyer are assured that the magnetos are back to a known baseline. For the seller and buyer, the Kelly Aero 500-hour inspection provides a warranty for the magnetos and simply removes any post-sale liability concerns for the ignition system after the aircraft purchase.
If the seller is not willing to provide the 500-hour inspection, then the buyer should consider spending the money to get the inspection done. Once again, the benefit is that the new owner can have Kelly Aero baseline the magnetos to a known condition. With one less thing to worry about, the new owner can fly their new airplane with greater confidence that unplanned magneto maintenance will not keep them grounded.
Have Fun and Fly! Harry Fenton, Director of Business Development and Product Support
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By Harry Fenton, Director of Business Development and Product Support, Kelly Aero Routine maintenance requirements and all special service actions required by Service Bulletins and Airworthiness Directives typically require that the magneto serial number or part number be referenced to verify compliance. The OEM data found on the magneto data plates is always the baseline to establish the applicability of the compliance of a required maintenance or safety action. However, what is required when an OEM data plate has been replaced by a company that is not the OEM for the magneto? What if a serial number is added to the data plate that is different than the OEM serial number? Do OEM requirements still apply? The bigger question: Is the magneto considered an FAA legal part if the OEM data plate has been removed and replaced by a non-OEM data plate? Replacement Data Plates- Is This Legal? The simple answer is “yes”, Kelly Aero replaces worn and damaged OEM magneto data plates with new Kelly Aero data plates. But, the “yes” answer is not as simple as it sounds. The FAA considers the management and disposition of OEM data plates attached to FAA-PMA articles as serious business. The real world for Kelly Aero is that there is no option: worn data plates must be replaced when magnetos are inspected or overhauled. In most cases, magnetos returned to Kelly as cores for overhaul, or for the 500-hour inspection, may be legible, but not in a useable condition to continue on in service.
The continued use of the OEM data plate for ongoing service and compliance becomes a safety issue if the information on the data plate becomes illegible. The only practical and safe solution is to make a new data plate stamped with the information from the old, worn data plate. The FAA has strict regulations against the removal and replacement of airframe, engine, propeller, and life-limited parts, though. They spell out what can, and cannot be done in the Federal Code of Regulations, Part 45. The FAA states, specifically, that data plates of Type Certificated or Life Limited items may be removed in the course of maintenance and must be reattached to the item from which they were removed. Replacement data plates for these items can only be provided by the OEM, but the FAA must approve and accept that process. This concept has been drilled into mechanics thinking by the FAA and industry guidance. The general understanding is that all data plates are forbidden to be replaced.
The data plates of component articles that are FAA-PMA approved, such as magnetos, are not as strictly controlled and the FAA can approve a repair process that does not require OEM approval for data plate replacement. Kelly Aero’s process to replace the worn OEM data plate with a new Kelly Aero data plate
is part of our FAA-approved Repair Station Quality Manual. This manual details the process to replace data plates, but also documents the strict record-keeping and traceability procedure required to preserve the OEM data plate and magneto model information. Bendix and Slick magnetos worked on by Kelly Aero for overhaul or 500-hour inspection are completely disassembled and all parts are cleaned and inspected to make the magneto look and work like new. During the teardown and inspection process, the OEM data plate is removed from the magneto frame in order to strip the paint from the magneto and repaint it to a new condition. The OEM serial number and magneto part number are permanently coded onto the magneto frame to preserve the record of that part. All of the information on the data plate becomes part of the extensive overhaul record of the magneto as it progresses through the Kelly Quality system. When the inspection and re-work steps are completed, a list of parts to overhaul or to complete the 500 hour inspection of the magneto is generated and added to the magneto record. At every step in the process, from disassembly to completion of the overhaul, the OEM data is part of the documentation record.
After the magneto assembly is completed, a new Kelly Aero data plate is made for the magneto. The data plate will show the OEM serial number, the Kelly Aero Overhaul serial number, and the part number of the magneto. The new Kelly Aero data plate is attached and the inspected magneto looks as good as new. An FAA Form 8130-3 Authorized Release Certificate is generated to document and release the 500-hour inspection magneto to service. If the magneto is overhauled, the data plate marking will be slightly different as compared to the 500 hour inspection. Kelly Aero Overhauled magnetos are treated more like new production magnetos and a unique Kelly Aero serial number is assigned to the magneto. The OEM serial number is also retained and both the Kelly Aero and OEM serial numbers are engraved on the new magneto data plate.
The Dual Identity of a magneto overhauled by Kelly Aero After overhaul, an FAA Form 8130-3 Authorized Release Certificate is generated to document completion of the overhaul process and to authorize the release to service of this part by Kelly Aero. It is at this point that the magneto develops a dual identity based on the specific requirements that apply to the OEM serial number or the Kelly assigned a serial number. Both serial numbers become equally important in terms of ongoing maintenance compliance. The most common misconception is that the Kelly Aero data plate changes the requirements to comply with OEM maintenance guidance. This perception is 100% wrong. All OEM Service Bulletins and Airworthiness Directives continue to apply to the magneto based on the underlying OEM magneto data, regardless if it was overhauled by Kelly Aero or by any other company. However, the Kelly Aero overhaul uses Kelly manufactured FAA-PMA parts and additional processes of inspection and workmanship which are not part of the basic OEM minimum requirements. These additional features make the Kelly Aero overhaul unique. These unique features may be affected by inspections or service needs different than, or in addition to, than OEM requirements. To track service requirements of the content added by Kelly to an overhauled magneto, a unique Kelly Aero assigned serial number is added to the data plate and is listed on the FAA Form 8130-3 Authorized Release Certificate supplied with the magneto.
Given the “dual Identity” of the magnetos serviced by Kelly Aero, the replacement Kelly Aero data plate is clearly more than just a simple cosmetic replacement. The Kelly Aero data plate ensures legibility for the service cycle of the magneto, which is required for ongoing compliance and safety requirements. The Kelly Aero data plate also adds the extra layer of traceability of the Kelly added components and workmanship. Ultimately, ALL applicable OEM and Kelly Aero service requirements must be complied with after the magneto is released to service, and the new Kelly Aero data plate assures that action can be accomplished. Do you have a question about Kelly Aero products or piston engine ignition systems? Contact us at https://kellyaero.com/about/contact-us/
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.
Utilizing over 25 years of Bendix/CMI magneto overhaul experience, Kelly Aerospace Energy Systems has developed a detailed 35 point checklist that complies with all applicable AD’s, service bulletins, and Continental Motors Master Service Manual to ensure a complete inspection of your aircraft magneto. Ask about our 500 hour inspection certification today!
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