MONTGOMERY, Ala., Nov. 27, 2023 – Hartzell Engine Tech, a portfolio company of Arcline Investment Management, has acquired the assets of Kelly Aero LLC, a leading manufacturer of aftermarket aircraft magnetos, replacement parts and ignition harnesses for General Aviation and military applications. Hartzell Engine Tech is headquartered in Montgomery, Ala. “With this acquisition, Hartzell Engine Tech is excited to add manufacturing capabilities for aircraft ignition products to our existing lines of engineered, firewall forward, engine accessories. We extend our appreciation to Jeffrey Ke ..read more

Getting to take out your aircraft on a  warm summer’s day can be a highlight of a good weekend or the best kind of start to your week. Taxiing out onto the tarmac to get ready to fly has to be one of the best feelings of anticipation there is. But sitting there sweltering in the heat coming off the hot asphalt can really put a damper on the excitement, and leave you just wishing you could be back inside rather than getting to enjoy the hard work you’ve put into making this plane ready for flight.  Luckily, Kelly Aerospace has the ability to help you get air conditioning into almost a ..read more

By Harry Fenton, Director of Business Development and Product Support “Timing” is equally a simple and extremely complicated term relative to the installation and operation of magnetos.  However, the word “timing” as applied to magnetos are a set of terms that means one thing, and many things, depending upon the context of the terms:  Internal Timing, External Timing, and Advance Timing are all examples of individual timing terms.  The sum total of all of these terms becomes what is broadly referred to as Magneto Timing. These terms are basic knowledge to aircraft technicians an ..read more

By Harry Fenton, Director of Business Development and Product Support When a customer orders a Kelly Aero ignition harness one of the choices is to order a harness with 5/8” or 3/4” nuts.  Why are these seemingly unrelated numbers used to describe an ignition harness? These fractions represent the dimensions of the internal diameter and thread pitch of the nuts that attach the ignition lead to the spark plug.  These dimensions have no reference to the width of the nut between the “flats” of the nut. The 5/8-24 nut is 5/8” internal diameter with a 24 thread per inch count, or “pitch ..read more

By Harry Fenton, Business Development and Product Support Lots of older Bendix magnetos are returned to Kelly Aero either as cores or for a custom overhaul with large external capacitors attached to the outside of the magneto.  Much to the surprise of the customer, this big capacitor is not replaced or provided as new as part of a Kelly Aero overhauled magneto.  In fact, this capacitor is not shown in the magneto overhaul manual or parts list, and there is little to no documentation as to how these parts are installed with the magneto.  So…what is this thing? This big capacitor ..read more

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 seri ..read more

READ THIS MAGNETO INSTALLATION GUIDE BEFORE INSTALLING MAGNETO TO ENGINE Confirm that the part number of magneto is approved for the engine installation. Refer to the most current application data at www.KellyAero.com. BEFORE INSTALLING DRIVE GEARS OR ADAPTERS: Connect a magneto timing tool to the magneto P-Lead and confirm that the contact points open and close by turning the rotor shaft. As required, install magneto drive gears or adapters in accordance with engine manufacturer data. Torque rotor shaft nut to 120 to 320 in. lbs. Install cotter pin and secure. Identify Magneto Rotation Ident ..read more

Despite its simplicity, the magneto timing synchronizer, commonly referred to as the magneto timing tool, can be one of the most frustrating tools for even the most experienced mechanic to use.   The difficulty of using this tool can be baffling as the theory of operation is as simple as it gets. Connect a lead to the magneto ground point, connect a lead to the p-lead terminal, and as the magneto rotor shaft is turned, a light on the front of the tool will turn on and off as the contact points open and close.  All too frequently, however, a mechanic will struggle with timing a magnet ..read more

READ THIS MAGNETO INSTALLATION GUIDE BEFORE INSTALLING MAGNETO TO ENGINE Confirm that the part number of magneto is approved for the engine installation. Refer to the most current application data at www.KellyAero.com. BEFORE INSTALLING DRIVE GEARS OR ADAPTERS: Connect a magneto timing tool to the magneto P-Lead and confirm that the contact points open and close by turning the rotor shaft. As required, install magneto drive gears or adapters in accordance with engine manufacturer data. Torque rotor shaft nut to 120 to 320 in. lbs. Install cotter pin and secure. Identify Magneto Rotation Ident ..read more

One of the most common inquiries we receive at Kelly Aero regards ignition harness applications.  The basic engine application data is usually easy as most mechanics or owners will know that their airplane has a Lycoming or Continental engine installed, and perhaps they know whether Bendix or Slick magnetos are installed.  However, that sort of general information is only partially useful.  It is the very specific data on the configuration of the engine and magnetos that defines the correct features of the ignition harness. So, what information or questions do you need to ask to ..read more