The FAA published special conditions on May 6, 2026, clearing a key regulatory hurdle for Xtreme Avionics, LLC — the company is pursuing a supplemental type certificate covering the Garmin GI 275 Standby Display, including its integrated rechargeable lithium-ion backup battery, in the Airbus Defense and Space Model C-212 series. The document (Federal Register No. 2026-08903) covers six specific variants: the C-212-CB, -CC, -CD, -CE, -CF, and -DF, all certificated under Type Certificate No. A43EU.
Xtreme Avionics filed the STC application on August 30, 2024. The FAA’s action doesn’t grant the STC itself. It establishes the additional safety standards that must be met before the certificate can be approved. A public comment period runs through June 22, 2026.
Why Special Conditions Were Needed
The C-212 is certificated as a twin-engine transport-category airplane carrying between 19 and 28 passengers depending on variant, with maximum takeoff weights ranging from 14,332 to 16,976 pounds. The problem is chemistry. Existing airworthiness standards under 14 CFR Part 25 — specifically § 25.1353 — were written with nickel-cadmium and lead-acid batteries in mind. Lithium-ion cells fail differently: higher energy density, thermal runaway risk, and cell-interconnect failure modes that legacy regulations simply don’t address.
The FAA’s language in the special conditions is direct:
“This type of battery has certain failure, operational, and maintenance characteristics that differ significantly from those of the nickel-cadmium and lead-acid rechargeable batteries currently approved for installation on transport category airplanes… Interconnection of these cells in battery packs introduces failure modes that require unique design considerations, such as provisions for thermal management.”
It’s the same regulatory logic the FAA applied to StandardAero’s Standby Attitude Module (SAM) installation on the Hawker 800/800XP in 2022, and to an earlier C-212 emergency lighting lithium battery installation (SC No. 25-795-SC, FAA-2021-1045). Xtreme’s STC is following an established — if still case-by-case — framework.
The Hardware — What’s Actually Going In
The GI 275 is a 3.125-inch round-mount electronic flight instrument that replaces vacuum-driven attitude indicators, HSIs, CDIs, or MFDs. Three variants exist: the base GI 275, the GI 275 ADAHRS, and the GI 275 ADAHRS+AP. The standby ADI configuration relevant here includes an internal lithium-ion phosphate backup battery — part number 11-19100 — housed inside a partitioned aluminum chassis designed for thermal containment.
Rated backup runtime is 60 minutes. Battery charging requires temperatures between 0°C and 60°C; the unit flags any out-of-range condition directly on the display. Maintenance requirements include a functional battery check every 12 calendar months and a timed discharge test every 392 days for legal IFR flight — both outlined in the installation manual, which is only released post-purchase. Battery replacement must be performed by a licensed A&P technician. The battery system is certified to RTCA DO-311A minimum operating performance standards for rechargeable lithium batteries in aviation.
The C-212 Fleet — Why This Matters
More than 210 C-212s remain in military and commercial service globally. Many are still flying with original analog instrument panels or piecemeal avionics upgrades — exactly the kind of fleet where a certified standby ADAHRS makes a real difference. The GI 275 standby ADI offers a direct path to eliminating vacuum system dependency: no pump, no regulator, no wet-compass-and-hope backup strategy. For operators already evaluating ADS-B compliance upgrades and glass cockpit modernization, 60 minutes of battery reserve on a certified standby ADAHRS is a meaningful addition to any retrofit package.
Worth noting: the standby ADI variant is a dealer-sale and dealer-install item. This is not an over-the-counter A&P installation like the base CDI/MFD (part number 010-02325-00). Operators should contact Xtreme Avionics directly to confirm installer authorization and pricing once the STC clears.
What’s Next
The comment period closes June 22, 2026. The FAA may revise the special conditions based on responses received before issuing final STC approval. No software version specific to the C-212 standby installation has been publicly disclosed — the GI 275 platform is currently at v3.20 for other applications. Xtreme Avionics has not announced a target STC completion date or installation pricing as of publication.
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