4.3 Weather, Performance & Segregation Checks Before 5 m Ops
Key Takeaways
- UAS.OPEN.030 allows reduction from the 30 m normal floor to a minimum of 5 m horizontal from uninvolved persons only when the manufacturer’s low-speed mode is active and the remote pilot has evaluated weather, UAS performance, and segregation of the overflown area.
- Five metres is a privilege, not a default: if any of weather, performance, or segregation is unsatisfactory, remain at ≥30 m (UK2/C2 normal) or do not fly the close task.
- A practical go/no-go checklist covers wind and gusts versus limits, visibility, battery and aircraft health, confirmed active low-speed mode, a clear buffer free of people and vehicles, pilot workload, and a viable abort path.
- Low-speed mode must be the aircraft’s engaged function, not an informal impression of flying slowly; confirm the mode on the system before treating 5 m as available.
- Even after a green checklist, apply 1:1 and reaction-time judgment—5 m is a legal floor, not a target height-agnostic spacing.
Why 5 m Needs a Formal Gate
For UK2 (and transitional C2-as-UK2) aircraft in A2 Near People operations, normal mode demands at least 30 m horizontal separation from uninvolved persons. The remote pilot may reduce that minimum to 5 m only when:
- The active low-speed mode function is engaged, and
- The pilot has evaluated weather conditions, performance of the unmanned aircraft, and segregation of the overflown area.
That structure is deliberate. Five metres leaves little time and space to correct mistakes. Kinetic energy is lower in low-speed mode, but wind, a tired battery, GNSS hop, or a person stepping from a doorway can still close the gap faster than a distracted pilot reacts. The A2 syllabus therefore treats the step-down as a conditional privilege, not the everyday A2 spacing.
Exam sentence to memorise: 5 m is allowed only with low-speed mode on and after weather + performance + segregation evaluation; it is never the automatic A2 distance.
Legacy sub-2 kg A2 aircraft do not get this 5 m package at all (Chapter 3): their person floor remains 50 m. Do not apply this section’s privilege to unmarked legacy types.
The Three Evaluations (Regulatory Core)
1. Weather conditions
Ask whether the meteorological environment lets you hold position, stop, and move away from people inside a tight buffer:
- Mean wind and gusts versus manufacturer limits and your personal minima (gust spread matters: 8 kt mean with 18 kt gusts is a different aircraft than 8 kt steady).
- Wind direction relative to people, obstacles, and your abort path (downwind toward a path is worse than a breeze into open segregated ground).
- Visibility and light — can you maintain VLOS and see approaching persons?
- Precipitation, icing risk, temperature — performance and battery behaviour change; wet props and low temperatures cut margins.
- Turbulence — mechanical turbulence near buildings can throw a slow multirotor several metres, which matters enormously at a 5 m floor.
If weather is borderline for a wide 30 m operation, it is failed for 5 m work. Tighten minima as you tighten separation.
2. UAS performance
Evaluate the actual aircraft state for this flight, not the brochure:
- Mass and payload — near MTOM increases inertia and can worsen braking/response.
- Battery health and state of charge — sag under load, cold packs, aged cells.
- Control responsiveness, braking, and low-speed mode behaviour — does the mode engage correctly and cap speed as designed?
- GNSS / position hold quality — multipath beside glass and steel can produce position jumps larger than 5 m.
- Sensors, firmware, and known faults — prop damage, vibration, compass warnings, geo-awareness alerts.
- Manufacturer data — never invent performance; if the manual warns against flight in current conditions, that is a no-go.
An aircraft that “usually flies fine” but shows GNSS yellow icons and a soft battery is not cleared for 5 m simply because low-speed mode can be toggled.
3. Segregation of the overflown area
This evaluation is the operational link to Section 4.1:
- Is the ground area under and beside the flight path actually free of uninvolved persons?
- Will it stay free for the duration of the close work?
- What controls enforce that (barriers, timing, marshals, briefed involved-only zones)?
- Are vehicles and animal traffic also managed? A car entering a courtyard can be as serious as a pedestrian.
If segregation is hope-based, the evaluation fails. Low-speed mode does not segregate a street.
Go / No-Go Checklist Before 5 m Ops
Use a deliberate checklist every time you intend to work inside the 30 m normal bubble. All items should be go before you treat 5 m as available; any no-go means stay at ≥30 m horizontal from uninvolved persons, relocate, or cancel the close task.
| Check | Go | No-go examples |
|---|---|---|
| Class mark & privilege | UK2 / transitional C2 + A2 CofC path | Legacy only → 50 m floor, no 5 m package |
| Low-speed mode | Mode confirmed active on the aircraft/system | “Flying gently” without mode; mode fault |
| Wind / gusts | Comfortably inside limits with margin | Gusts near limit; rotor-turbulence alley |
| Visibility / VLOS | Clear view of UA and approach routes | Fog, dusk glare, visual obstacles |
| Battery / health | Healthy pack, adequate %, no critical warnings | Low %, swollen cell, persistent errors |
| Performance / hold | Stable hover, crisp response, good GNSS | Position hop, sluggish braking, heavy payload issues |
| Segregation / buffer | Clear buffer free of uninvolved people & vehicles | Open public access, failed barriers |
| Involved persons | Briefed and in planned positions only | Unbriefed “helpers” under the aircraft |
| Pilot workload | Capacity for aircraft + people watch (spotter if needed) | Solo pilot + complex cinema moves + busy edge |
| Abort path | Clear lateral escape and contingency landing | Only escape is over the public or into obstacles |
| 1:1 judgment | Planned horizontal ≥ max(5 m floor, height AGL, extra margin) | Planning to sit at 5 m at 25 m AGL as a “target” |
Worked go/no-go
Go example. UK2 multirotor, low-speed mode on and verified, 6 kt steady wind, full healthy battery, strong GNSS in an open private yard, fence locked, only briefed client inside a marked safe corner, pilot plus spotter, contingency grass pad into wind, task hover at 6 m AGL so 1:1 ≈ 6 m and you elect ~10 m from the fence line to uninvolved persons outside. Privilege may be used with continued monitoring.
No-go example A — weather. Mode on, but 15 kt gusting 25 kt between buildings. Evaluation of weather fails → remain ≥30 m or do not fly close; preferably postpone.
No-go example B — performance. Mode on, calm air, but GNSS unstable beside a glass atrium and the aircraft wanders. Performance/hold fails → open distance, land, or redesign.
No-go example C — segregation. Mode on, perfect aircraft, but a public footpath cuts 4 m from the planned hover and cannot be closed. Segregation fails → 5 m privilege unavailable.
No-go example D — workload. Everything physical looks good, but the pilot is alone, flying a complex orbit, talking to a client on the phone, and cannot scan for people. Workload/attention fails as an operational evaluation even if the regulation’s three words are “weather, performance, segregation”—professional application includes being able to act on what those evaluations imply.
Privilege, Not Default
Training and exam culture must fight the idea that “A2 means I always work at 5 m.” Correct framing:
- Default mental model for UK2 A2: 30 m horizontal from uninvolved persons, no overflight.
- Optional reduction: 5 m minimum after mode + three evaluations, still no overflight, still use 1:1 and extra margin as needed.
- Any doubt: favour the larger distance or land.
Clients may push for close product shots. Your answer is the checklist, not their timeline. RAEs and theory questions reward the pilot who declines 5 m when segregation is soft.
Mid-Flight: Privilege Can Be Lost
Evaluations are not only a pre-take-off tick box. If conditions change:
- Wind builds → open to ≥30 m or land.
- Battery warning → leave the close volume; land with reserve.
- Person enters buffer → Section 4.2 actions; re-evaluate whether 5 m remains justified.
- Low-speed mode disengages or fails → you are back to normal mode floors immediately (30 m for UK2), not “approximately 5 m because I was careful.”
Build abort path thinking into the 5 m plan: know the direction of escape that increases horizontal distance from people without overflying them, and know the contingency pad that stays empty.
Linking Chapters 3 and 4
| Layer | Content | Role at 5 m |
|---|---|---|
| Statutory floor | 5 m min with mode + evaluations | Hard minimum |
| 1:1 rule | Horizontal ≥ height AGL when that exceeds 5 m | Often raises spacing above 5 m |
| Site selection (4.1) | Footprints, briefing, FRZs, contingency L | Makes segregation evaluation true |
| Reaction (4.2) | Restore distance, no overflight, abort | Handles evaluation failures in real time |
| Technical mitigations (Ch 5) | Prop guards, etc. | May reduce harm but do not replace 5 m legal conditions |
Technical mitigations never rewrite UAS.OPEN.030: prop guards do not alone unlock 5 m on a legacy airframe, and they do not replace weather or segregation checks on a UK2.
Memory Hooks for Section 4.3
- Mode + weather + performance + segregation — all required for 5 m.
- 5 m = privilege, 30 m = default UK2 mental model.
- Confirm mode engaged — not informal slow flight.
- Checklist includes buffer clear, workload, abort path.
- Conditions change → privilege ends; open distance or land.
Master this gate and you connect air law numbers to the operational and technical ground-risk story the A2 CofC exam is built to test.
Under UAS.OPEN.030, when may a remote pilot reduce horizontal separation from uninvolved persons to a minimum of 5 m with a UK2 or transitional C2 aircraft in A2?
A pilot intends 5 m operations. Low-speed mode is on, the aircraft is healthy, and wind is light, but the planned hover sits beside an uncontrolled public footpath that cannot be closed. What is the correct decision?
Which statement best reflects the correct attitude to the 5 m distance in A2 training and operations?
During a UK2 flight authorised under the 5 m privilege, low-speed mode disengages and cannot be restored, while uninvolved persons remain nearby. What should the pilot do regarding separation?