The Collins 331A-3G is a Horizontal Situation Indicator (HSI) designed to integrate navigation and heading information into a single, easy-to-read display. This instrument enhances situational awareness by combining data from various navigation sources, allowing pilots to maintain precise course guidance.

Key Features:

•Model: 331A-3G

•Part Number: 522-2638-007

•Serial Number: 10517

•Functionality:

•Displays aircraft heading, course deviation, and glide slope information

•Integrates with VOR, ILS, and GPS navigation systems

•Features heading, course datum, and bootstrap synchros

•Lighting: 28V blue-white internal lighting for enhanced visibility 

•Compatibility: Suitable for various general aviation aircraft; consult your aircraft’s maintenance manual or a certified avionics technician for specific compatibility

•Dimensions: Standard 3-ATI panel mount

•Weight: Approximately 3.2 lbs

Condition:

This unit is in good used condition, with all functions operational upon last inspection. Minor cosmetic signs of wear are present, consistent with regular use. Please refer to the detailed photos for a closer look at the item’s condition.

Additional Information:

I’m not an avionics shop—just selling extra gear. Everything is sold as-is with no warranties. It’s up to you to ensure it works for your setup. Feel free to ask any questions before buying.

I’ll ship it however you prefer—economy, priority, second-day air, etc. If you need it fast, let me know, and I can update the shipping. Happy to combine shipping—just add items to your cart and request an update. Please note, I offer shipping only—no local pickup.

If you’re not satisfied with your purchase, reach out within 30 days, and we’ll sort it out. The item must be returned in the same condition.