ExpressLRS at 50mW punches through walls. At 250mW with a decent patch antenna on the ground, you're looking at 30km+ link budgets. In an open country, that's incredible. In the UK, it creates a serious legal tension.
The BVLOS problem
UK UAS regulations require you to maintain visual line of sight (VLOS) with your aircraft at all times during Open Category operations. The legal VLOS definition is approximately 500m in clear conditions for a typical micro quad — your radio link range is irrelevant to the law.
Flying beyond VLOS requires a specific operations risk assessment (SORA) submitted to the CAA and an Operational Authorisation. This is achievable for commercial operators but essentially out of reach for casual hobbyists.
What you can do legally
- Long-range fixed-wing flying within VLOS — large, high-visibility aircraft can be seen at 800m+ in good conditions
- Using an observer to extend effective VLOS — legal if continuous communication is maintained and the observer can take control
- Flying at high altitude sites (mountains, open moorland) where visual range naturally extends
ELRS configuration for UK legal flying
There's no legal requirement to limit link range — the restriction is on where the aircraft goes, not how far the radio can reach. A 30km-capable link with a short failsafe set to RTH within 500m is compliant under the Open Category.