Helicopter avionics and instruments — what to buy, what to sell, what to upgrade

Avionics are the highest-CPC, fastest-evolving category in helicopter parts: Garmin G500H TXi glass, GTN 650/750 navigators, ADS-B Out compliance kits, HTAWS, four-axis autopilots and digital intercoms. ChopperSwap lists them new, removed-serviceable and overhauled, with tag and serial traceability enforced.

Avionics upgrade cycles drive the busiest sub-category in the helicopter parts market. When an operator retrofits glass, the analog instruments coming out are often nearly new and re-enter the market as removed-serviceable units at 30–60% of new pricing — perfect for operators keeping older airframes flying without certifying glass.

Conversely, when a hull is written off, its modern avionics stack (Garmin G500H TXi, GTN 750, GTX 345R, KI 300) often outlives the airframe and resurfaces on ChopperSwap weeks later.

ChopperSwap requires sellers to declare manufacturer, part number, serial, condition, tag type and any STC association at upload — so glass-cockpit retrofit shoppers and analog-fleet maintainers both find what they need.

Steps

1. Search by manufacturer and model — Garmin GTN 650/750, G500H TXi, GTX 345R, GI 275, GMA 350H — or Honeywell, Bendix-King, Avidyne. Filter by condition (new, OH, SV) and by STC if you need approved-model-list coverage.
2. Verify the tag — New units come with manufacturer 8130-3. Removed-serviceable units must have a current 8130-3 from an approved Part-145 shop with bench-test data.
3. Confirm software / database currency — For Garmin navigators and ADS-B units: confirm software version and database status. Out-of-date units may need a paid update before installation.
4. Check STC and approved-model-list — A Garmin G500H TXi for a Bell 407 is not interchangeable with one for an AS350. Confirm the STC covers your model and serial range before buying.
5. Confirm DPDT (dummy plug) and wiring loom — Many removed units come without their original wiring loom — factor in $2k–
6. Post an Avionics Wanted request — Need a specific GTN 750H with WAAS for a Robinson R66? A free Wanted post reaches every parts seller and shop on ChopperSwap.

Why ChopperSwap

Avionics as a first-class category

Manufacturer, P/N, serial, condition, tag and STC are required fields at upload.

Removed-serviceable supply

When operators retrofit to glass, ChopperSwap is often the first marketplace where their removed analog units appear.

Shop & operator audience

Listings are seen by both end-user operators and avionics installation shops — wider liquidity than OEM-only channels.

Frequently asked questions

Where can I buy a used Garmin GTN 750H?

ChopperSwap lists removed-serviceable Garmin GTN 650/750 navigators with current 8130-3 tags. Filter the Avionics category by manufacturer and model, and confirm the STC covers your airframe.

Can I install removed-serviceable avionics?

Yes — as long as the unit has a current 8130-3 from an approved Part-145 shop and the STC (or your airframe TC) approves installation. An avionics shop will confirm during the pre-install paperwork review.

How much does a helicopter ADS-B Out upgrade cost?

Typical helicopter ADS-B Out installation runs $6k–