AEA Pilot's Guide 2018-2019 - 45
all-glass, all-electrical panel. Consider these approaches to assuring power for all-electrical aircraft. The Gold Standard: stand-alone standby electrical power Original equipment manufacturers offered dual alternators and, in some cases, dual batteries going back decades, years before anyone in general aviation uttered the words "primary flight display." With digital cockpits the dominant standard in today's factory-new aircraft, electrical power redundancy has become more common. The catalyst? The need for redundancy to power allglass instrument panels. You'll find dual electrical systems like this as standard on many factory airplanes with EFIS cockpits: Beechcraft G36 Bonanzas and G58 Baron twins; Cirrus Aircraft SR20 and SR22 models; current production Mooneys; even the modest Cessna singles, the 172, 182 and 206 sport dual buses. Many of these sport dual everything: alternators, to produce electrical power; batteries and regulators, to control the output and sharing of power from the two alternators; and dual buses. For glass-panel aircraft lacking these capabilities, avenues exist for some aircraft to add them. Depending on the airframe, supplemental type certificates may provide the path to adding a second alternator and a regulator capable of handling both the main and second generating source. Several vendors offer packages that add a standby alternator, some driven off the engine accessory drive normally used to power the nowunneeded suction or pressure pump, along with the regulator capable of controlling both - including picking up the load when the main alternator fails. B&C Specialty Products offers standby alternator packages for many popular aircraft, including a regulator capable of handling the changeover. Both belt-driven and gear-driven options are available, and the company holds STCs for many aircraft. B&C also holds STCs and offers kits to fit its standby alternator systems in various aircraft, among them the Beechcraft Bonanza, Cessna 210 and Piper PA32. Basic Aircraft Products also offers STCs for its ram-air turbine-powered standby alternators for several airframes. In essence, the ram-air turbine pops out where airflow through turbine blades drives an alternator. Fourteen-volt systems available from BAP include most Aeronca models, short-wing Pipers through the Super Cub, Taylorcraft BC 12-D, the Luscombe 8 series and Boeing Stearman. Another avenue for adding alternate electrical power involves using the field approval approach to add a second bus and a standby battery. But other avenues exist to assure power continues to flow to digital panels. EFIS with integral standby power In many instances, avionics manufacturers offer integral standby power in or for today's modern EFIS gear. Avidyne, Aspen Avionics, Dynon and Garmin offer the option of a standby battery for their systems. For example, Aspen's Evolution line of PFDs and MFDs come standard with both a standby battery and a GPS navigation receiver. For VFR-only pilots, Aspen's certified VFR PFD offers an inexpensive path to adding modern solidstate indications for the entire six-pack of analog flight instruments in a standard panel for about $4,000 plus installation. And that includes the standby battery and GPS. Aspen's higher IFR-approved PFD and its line of MFDs also include the standby features as standard - and the battery satisfies the regulatory requirement for that instrument. Garmin offers the option of a standby battery for both its new G600 TXi and G500 TXi PFDs, also satisfying the emergency-power requirement. Ditto for Garmin's G5 instrument, which is approved as a replacement attitude indicator and, in a second unit, a DG and HSI - with a GPS interface as an option. The G5 can be equipped with its own integral standby battery to keep the units working for more than two hours in the event of the loss of main-ship power. Continued on following page... - 45 -
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