FAA rule update for TSO radio install without 337

🛠️ FAA Rule Upgrade: Installing TSO Radios Without Field Approval

The FAA has significantly updated its stance on the installation of TSO-authorized avionics—making it easier and faster for aircraft owners and A&Ps to upgrade legacy panels without the need for field approvals in many cases.

🚀 What Changed?

The FAA has clarified that installing a TSO-authorized radio like the ICOM A220 or the Garmin GTR 205, no longer requires a Form 337 field approval if the installation is considered a minor alteration and uses acceptable or approved data.

🔍 TSO ≠ Automatic Installation Approval

While a TSO (Technical Standard Order) certifies that an avionics component meets FAA performance standards, it does not automatically grant installation approval. However, when the installation uses:

TSO installation instructions

Compatible electrical and airframe integration

Proper documentation in the aircraft maintenance log

…it typically qualifies as a minor alteration, not needing field approval.

✍️ Backed by Regulation

Here’s the key regulatory basis for this change:

14 CFR § 43.3(g) – Authorizes minor alterations using acceptable data.

AC 43-210A – Clarifies field approval policy: minor alterations do not require a 337.

FAA Order 8300.16A – States that field approval is only necessary if:

1. The alteration is major, and

2. Approved data is unavailable.

If you have a TSO install guide or approved data (including from a DER or ODA), you’re covered—no 337 needed.

🧰 Installation Best Practices

To remain compliant:

Evaluate whether the installation is minor or major.

Use approved or acceptable data (TSO installation manual, DER-approved data, etc.).

Record the alteration in the aircraft maintenance logs with sufficient detail.

Confirm no adverse effect on aircraft systems, structure, or safety.

✅ Real-World Implication: The AV-30

For most general aviation aircraft, the AV‑30 qualifies as a minor alteration when installed with its published documentation. That means A&Ps can perform the upgrade without FAA coordination, as long as proper logbook entries are made.

🧭 Summary Table

Installation Type Needs 337? Notes

TSO radio (minor) ❌ No Logbook entry only

TSO radio (major, no approved data) ✅ Yes Field approval required

TSO radio (major, with DER/ODA data) ❌ No Logbook entry + data retained

At FlightWorthy, we stay ahead of the regs so you don’t have to. Our platform helps aircraft owners, pilots, and A&Ps track work, manage compliance, and streamline upgrades—like this one.

✈️ Learn more at FlyFlightWorthy.com

Note that the A&P is responsible for interpretation of the FAA regs, not FlightWorthy, and the Owner is responsible to make sure everything is signed off.