Safety & tech

FPV video loss

Analogue or digital FPV video cuts out in flight. DJI OcuSync/Lightbridge, ExpressLRS, Crossfire, analogue 5.8 GHz VTX, Walksnail/HDZero.

A2STS editorial12 min read

Contents

Overview

Analogue or digital FPV video cuts out in flight.

DJI OcuSync/Lightbridge, ExpressLRS, Crossfire, analogue 5.8 GHz VTX, Walksnail/HDZero.

Symptoms

Typical "FPV video loss" signs in flight, app or OSD:

  • Black screen in goggles
  • Static/snow on analogue
  • Digital — link lost on HD system
  • Log RSSI/LQ during flight — where link drops.

Common causes

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

  • VTX overheating or antenna disconnected
  • Wrong channel/band
  • HD: O3/Walksnail firmware or antenna damage
  • Metal frame blocking VTX antenna

Tools needed

Prepare before diagnostics — saves time in the field:

  • Two data-capable USB cables
  • ELRS/Betaflight Configurator
  • Antenna and u.FL/MMCX checker

Step-by-step fix

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

  • Check VTX antenna and mount — clear of props.
  • Analog: channel scan; digital: re-bind air unit and goggles.
  • Lower VTX power for testing; increase only if legal in EU.
  • Replace cable (MMCX/u.FL) if suspect break.

Additional diagnostics

Log RSSI/LQ during flight — where link drops.

Ground failsafe test before each session.

Channel scan — verify clean channel away from Wi-Fi.

When to contact service

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

  • RX/VTX antenna physically damaged after crash.
  • Link fails even at 5 m — hardware replacement.
  • DJI RC screen won't boot — service.

Prevention

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

  • Antenna check ritual
  • VTX pit mode on ground

Frequently asked questions

Is it safe to fly with "FPV video loss"?
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 “FPV video loss” 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.

Authority & sources

A2STS Editorial · Reviewed by: EASA UAS syllabus aligned