Duncan Aviation is offering its Pilatus PC-12 customers the new Archangel Systems Attitude & Heading Reference System (AHRS), which is designed specifically to replace the obsolete LITEF LCR-92/93 AHRS. As Pilatus owner/operators know, the LCR-92/93 delivered dependable service for decades. However, as the units age, support has become limited, repair costs are rising and turnaround times are increasing, necessitating longer downtimes, while the available upgrade paths can require significant investment.

Duncan Aviation supported Archangel's certification efforts as it worked through the installation and integration of the new system. The FAA recently approved the Archangel AHRS, and Duncan Aviation can now install it in all of its main MRO facilities and all of its satellite avionics shops. Because of the straightforward nature of the installation and its use of existing architecture, its techs can even come to the owner's or operator's hangar to install this new AHRS. Duncan Aviation can complete most installations in less than a week, making fairly quick return-to-service.

“It's been a pleasure working with Duncan Aviation during the development of this certification project and the initial installation at the Duncan Aviation Dallas satellite facility. It has been thorough and professional, and we've relied on its avionics and engineering expertise as we developed the STC for our new Attitude & Heading Reference System (AHRS),” says VP of business development at Archangel Systems Aria Bahawdory. “We are confident that our new AHRS will provide Pilatus owner/operators with a practical, dependable, affordable system to replace their obsolete inertial sensing systems.” With 2,000 PC-12s delivered by May 2023, the Pilatus type is the most widely operated single-engine turboprop in business aviation.

The Archangel Systems' solid-state AHRS unit replaces the LITEF LCR-92/93 with current-generation inertial sensing technology that preserves compatibility with the aircraft's existing avionics architecture. The upgrade incorporates Archangel's AHR75 and AHR150A inertial sensing systems, magnetic sensing units and digital-to-analogue converters, and it includes a dedicated installation kit with adapter harnesses and mounting hardware.

More practical, the new Archangel adapter plates fit the existing LCR-92/93 mounting locations, while adapter harnesses allow the new system to connect to the existing aircraft wiring without requiring any modifications to the original wiring, which avoids extensive and expensive structural modifications to the flight deck or aircraft. This fully certified new system weighs roughly the same as the LCR-92/93, requires no periodic maintenance and provides comparable accuracy as demonstrated during extensive flight testing. The components are TSO-approved and incorporate Level A software. The AHR150A also incorporates a Reduced Vertical Separation Minimum capable air data system that supports potential future avionics upgrades.