Approach Aviation has introduced an enhanced set of patent-pending tools designed for proper installation, removal, and testing of alternator drive couplings on Continental engines.
The company’s first tool kit, ADCKIT1, supported Continental IO-520/550 engines. The new kit, ADCKIT2, adds support for alternator drive coupling inspection and installation on Continental C-75/85/90/115/125/145, E-165/185/225, O-200/300, IO-240/360 series engines, in addition to the IO-520/550.
The alternator drive coupling plays an important role in engines with direct-drive, gear-driven alternators, according to company officials. The coupling provides a shear point protecting the engine from damage should the alternator fail. However, it is imperative that the coupling be installed properly and inspected every 500 hours or any time that the alternator is removed from the aircraft.
This critical component has been the subject of several Service Bulletins (SBs) and Special Airworthiness Information Bulletins (SAIBs) because an out-of-tolerance or improperly installed coupling can lead to catastrophic engine failure, company officials noted.
The lack of specialized tools to perform these tasks has made compliance difficult, increasing the risk that these critical inspections are not being performed in the field, according to Approach Aviation officials.
In addition, alternator coupling slippage is a frequent cause of low alternator output. Without the tools to properly inspect the coupling, these failures are often misdiagnosed as a failure of the alternator, resulting in wasted time and money for both shops and owners, company officials added.
The new tools are purpose-built to make it easy for mechanics to inspect this component and simplify coupling installation and removal, officials said. The tool kit consists of a zinc-coated coupling spanner wrench and coupling gear socket with steel housing and aluminum gear engagement, designed to protect the steel coupling gear from damage during maintenance. Together, these tools allow the coupling to be held in place (mounted on the alternator or free-standing) while the coupling gear slippage is checked with a calibrated torque wrench (as specified in the engine maintenance manual), company officials explained.
The kits can be purchased directly at Approach Aviation or from retailers including Aircraft Spruce and Aircraft Tool Supply. Price: $239.95.