GPS fails indoors

Overview

No GPS lock indoors — position hold will not work.

Common on: DJI Mini/Mavic/Air, Autel, FPV with GPS module (BN-220, M10), INAV GPS rescue.

Symptoms

Typical "GPS fails indoors" signs in flight, app or OSD:

• 0 satellites indoors
• ATTI only
• Drift near windows
• Log satellite count, HDOP and RTH status before arming.

Common causes

Before replacing parts, rule out software, mechanical and environmental causes:

• Roof blocks satellites
• Multipath near glass
• Expected limitation

Tools needed

Prepare before diagnostics — saves time in the field:

• Open area away from metal
• DJI Fly / Pilot or Betaflight Configurator
• Flight log export

Step-by-step fix

Work safely: battery off when working on ESC/motors; props removed; after repair — VLOS test flight.

• Fly ATTI with caution — no GPS rescue indoors.
• Optical flow drones may hover better indoors.
• For FPV — manual mode only; no GPS rescue.

Additional diagnostics

Log satellite count, HDOP and RTH status before arming.

Compare behaviour indoors vs outdoors — confirms GPS limitation.

FPV: Betaflight GPS tab — baud 57600/115200, mag alignment.

When to contact service

If any of the following apply — do not fly and contact authorised service:

• GPS still shows no satellites after calibration and firmware update.
• After crash — physical GPS antenna or cable damage.
• Compass wrong even in open field — service required.

Prevention

Prevention reduces failure risk and supports EASA Open / VLOS compliance:

• Do not rely on GPS indoors

Frequently asked questions

Is it safe to fly with "GPS fails indoors"?

No if the fault affects navigation, power, ESC or link. Fix on the ground first, then conduct a VLOS test flight in open area.

How long does diagnosis take?

Most “GPS fails indoors” cases — 15–45 min on the ground. Complex ones (firmware, hardware) may need 1–2 h and service.

Must I register repair with the NAA?

No mandatory repair registration, but a maintenance log is recommended for commercial operations.