Quick Answer
A typical FPV drone flies 1 to 4km on stock ELRS 2.4GHz control with a 600mW analog VTX. Push ELRS to 500mW with a directional tracking antenna and 10km+ is achievable on the control link. DJI O4 digital video systems advertise up to 6km (CE) or 10km (FCC) range. But your video feed, not your control link, is usually the limiting factor, and UK VLOS law restricts legal flying distance to 300 to 500m regardless of hardware capability.
Control Link Range: ELRS vs Crossfire
Your radio link keeps you in command. In the UK, the two dominant systems are ExpressLRS (ELRS) on 2.4GHz and TBS Crossfire on 868MHz.
ELRS at 250mW with a standard receiver like the RadioMaster RP1 V2 reliably reaches 1 to 2km in suburban environments. We have tested this on workshop builds: solid link past 1.8km with stock dipoles before RSSI warnings triggered. A diversity receiver like the Happymodel EP1 TCXO adds 30 to 40% more usable range by handling multipath interference.
At the legal UK EIRP limit of 100mW on 2.4GHz, expect about 1km with stock omni antennas. Bump to 250mW (above the UK EIRP limit) and you see 1 to 2km. At 500mW with a ground-side directional tracking antenna like the MFD Crossbow, community tests and our own attempts have logged 10km+ on 2.4GHz ELRS. The ELRS community range table confirms these figures.
Crossfire runs on 868MHz in Europe (915MHz in the US). The lower frequency punches through trees and buildings far better than 2.4GHz. A 250mW Crossfire setup routinely hits 10 to 15km line of sight, at the cost of larger antennas.
For most UK pilots flying 5-inch freestyle or whoops, ELRS is the practical choice. If you plan regular flights beyond 3km, Crossfire or ELRS on 868/915MHz is worth the antenna bulk.
Video Range: Analog vs Digital vs DJI
Your video feed is usually the limiting factor, not your control link. Analog 5.8GHz video at 25mW gives you roughly 200 to 400m with basic antennas. Bump the VTX to 600mW with a decent FlyFishRC Osprey antenna and you reach 1 to 1.5km in open air.
Digital systems like DJI O4 and Walksnail match or slightly exceed analog range at the same power, but handle interference differently. Analog degrades gradually with static so you can fly through noise. Digital holds a clean picture then cuts out suddenly, meaning you need a larger safety margin.
The DJI O4 Air Unit Pro is the current range leader among FPV digital systems. DJI specifies 15km (FCC) or 8km (CE/SRRC) video transmission range, operating on both 5.1GHz and 5.8GHz bands with a 60MHz channel bandwidth. The standard DJI O4 Air Unit is rated at 10km (FCC) / 6km (CE). In practice, UK pilots on the CE power limit see 2 to 4km before the digital link drops. Our DJI O4 setup guide covers the full configuration.
The TBS Unify Pro 5G8 HV at 800mW with a good RHCP antenna is our go-to for analogue builds that need solid video past 1km. Match it with a quality patch antenna on your goggles and 2km analogue video is realistic in open terrain.
Range by System and Power Level
Reliable ranges based on our testing, customer feedback, and manufacturer specifications:
| Setup | Power | Control Range | Video Range |
|---|---|---|---|
| ELRS 2.4GHz + Analog 25mW | 100mW / 25mW | ~1km | 200 to 400m |
| ELRS 2.4GHz + Analog 600mW | 250mW / 600mW | 1 to 2km | 1 to 1.5km |
| ELRS 2.4GHz + DJI O4 | 250mW / O4 CE | 1 to 2km | 2 to 4km |
| ELRS 2.4GHz + DJI O4 Pro | 500mW / O4 Pro CE | 2 to 5km | 4 to 8km |
| ELRS 2.4GHz + tracking antenna | 500mW / Analog | 10km+ | 2 to 3km (bottleneck) |
| Crossfire 868MHz + Analog 800mW | 250mW / 800mW | 10 to 15km | 2 to 3km |
Video range is almost always the bottleneck. Better antennas and a higher-power VTX should come before a control link upgrade.
What Actually Limits Your Range
Frequency matters, but environment matters more. A 25mW VTX on a clear hilltop can outperform 1W through a suburban housing estate. These are the factors we see catching people out:
- Trees and foliage: 5.8GHz video drops fast through wet leaves. 868MHz control links barely notice.
- Antenna orientation: A vertically polarised antenna tilted 45 degrees loses 3dB (half your range). We see this on nearly every build that comes through the workshop for range complaints.
- Antenna placement: A VTX antenna buried between carbon fibre plates or next to a 4-in-1 ESC is fighting its own drone. Keep it clear and vertical. See our antenna placement guide for the full breakdown.
- VTX power settings: Running 25mW when your flight plan needs 400mW is the most common mistake we see from pilots who think their gear is faulty. Our VTX power guide covers this in detail.
- Frequency congestion: At a busy flying meet, Raceband channel 1 might be swamped. Always check for clean channels before a long-range attempt.
Is Long Range FPV Legal in the UK?
This is the question most range guides ignore. Having the hardware to fly 10km does not mean you are allowed to.
Under CAA regulations, you must maintain Visual Line of Sight (VLOS) with your drone at all times in the Open Category. That means you need to be able to see it unaided (binoculars do not count). For most people, that is 300 to 500m depending on drone size and eyesight. Flying on FPV goggles alone does not satisfy VLOS unless you also have a visual observer standing next to you maintaining direct eye contact with the drone.
Beyond Visual Line of Sight (BVLOS) flying requires specific CAA authorisation, typically through the Specific Category. This involves submitting a safety case, risk assessment, and operating procedures. It is not something you can do casually on a Saturday afternoon.
There is also the FPV exception: in the Open Category A3 subcategory, you can fly FPV with a visual observer, but the observer must maintain unaided visual contact and the drone must stay within the observer's VLOS. This effectively limits you to the same 300 to 500m regardless of what your ELRS link can handle.
See our full guide to UK drone laws for the complete regulatory picture.
Ofcom RF Power Limits: What You Can Actually Transmit
Your hardware range means nothing if you are transmitting illegally. Ofcom sets maximum EIRP (Effective Isotropic Radiated Power) limits for the bands FPV pilots use:
- 2.4GHz (ELRS control): 100mW EIRP maximum in the UK. Many ELRS modules can transmit at 500mW or 1W, but doing so exceeds the legal limit. At 100mW, realistic ELRS range is around 1km with stock antennas.
- 5.8GHz (video): 25mW EIRP without a licence. This is why most analogue VTX units default to 25mW. Higher power settings (200mW, 600mW) are available on the hardware but exceed what Ofcom permits for unlicensed use. DJI digital systems transmit at up to 14dBm (25mW) EIRP on 5.8GHz under CE rules.
- 868MHz (Crossfire/telemetry): 25mW EIRP in the EU/UK on the SRD868 band. Crossfire at 250mW is over the legal limit for this band.
We are not going to pretend every pilot complies with these limits at every field. But you should know what the law says, especially if you fly near populated areas where interference could affect other services. The practical implication: your legal range on 5.8GHz video at 25mW is 200 to 400m, and no antenna upgrade changes the power restriction.
FAQ
Q: How far can an FPV drone fly?
A: A stock 5-inch FPV build with ELRS 2.4GHz and a 600mW analog VTX flies 1 to 2km before video degrades. With DJI O4 digital video, expect 2 to 4km under UK CE power limits. Pushing ELRS to 500mW with a directional tracking antenna extends control range past 10km, but UK VLOS law restricts legal flying distance to 300 to 500m without a visual observer.
Q: What is the range of ELRS on 2.4GHz?
A: At the UK legal limit of 100mW EIRP, expect about 1km with stock omni antennas. At 250mW you see 1 to 2km. At 500mW with a ground-side directional antenna, 10km+ is achievable. ELRS uses 2.4GHz, the same band as WiFi, so range drops significantly in congested environments.
Q: What is the range of DJI FPV digital video?
A: The DJI O4 Air Unit Pro is rated at 15km (FCC) / 8km (CE) by DJI. The standard O4 Air Unit is 10km (FCC) / 6km (CE). Under UK CE power limits, practical range is 2 to 4km before the digital link drops. DJI digital holds a clean picture longer than analog but cuts out suddenly rather than degrading gradually.
Q: Can I fly 5km with a standard ELRS setup?
A: The control link can handle it if you push ELRS to 500mW with a good antenna. The problem is video. Most pilots lose their analogue feed between 1 and 2km on 5.8GHz. To reach 5km you need either a DJI O4 digital system or a directional tracking antenna on the ground. Both are technically possible but push you well past legal VLOS limits in the UK.
Q: Does a more expensive receiver give more range?
A: Diversity receivers with two antennas handle multipath interference better, which translates to more usable range in practice. But the antenna and transmitter power matter far more than the receiver price tag.
Q: Why does my range vary so much between flights?
A: Environmental factors shift constantly. Wet trees absorb more signal. Other pilots on adjacent channels raise the noise floor. Log RSSI and SNR in blackbox to compare flights objectively.
Q: Should I upgrade antennas or VTX power first?
A: Antennas, every time. A good directional patch antenna on your goggles can double your range for a modest cost. Increasing VTX power from 25mW to 600mW helps too, but a decent antenna at 200mW will outperform a cheap antenna at 1W. Start with the antennas collection before chasing more power.
Q: Can I get an Ofcom licence for higher power?
A: Ofcom does issue licences for higher power on some bands, but the process is aimed at commercial operators, not hobbyists. For most FPV pilots, the practical path is optimising antennas and placement within the 25mW/100mW limits rather than pursuing a licence.