FlyCart 30 Night-Line Spraying: How a 30 kg Payload-to-Weight Ratio and Winch System Tamed EMI on a Live Power Grid
FlyCart 30 Night-Line Spraying: How a 30 kg Payload-to-Weight Ratio and Winch System Tamed EMI on a Live Power Grid
TL;DR
- A 90 kV substation 80 m from the right-of-way flooded the 2.4 GHz band with EMI; a 3 cm antenna tilt on the FlyCart 30 restored -40 dBm link margin and kept BVLOS night ops inside SLA.
- Dual-battery redundancy delivered 18 min hover reserve after an unexpected 12 min weather hold, letting the crew finish 6 km of insulator spraying without landing for swap-out.
- Winch system lowered 30 kg payload to ground in 38 s when wind shear hit 15 m s⁻¹, eliminating human climb-down and keeping the line energized.
The Mission Profile: Night Spraying on 220 kV Circuits
Energized-line washing at night is the fastest way to cut salt-fog flash-over risk during monsoon season. The brief: coat 6 km of triple-bundle insulators with silicone-based hydrophobe, keep the circuit live, finish before civil dawn, and stay below €2 k per km all-in. Conventional bucket trucks would need three outages and a daylight lane closure. The FlyCart 30 with 30 kg payload, IP55 sealing, and a winch-based emergency set-down offered a zero-outage alternative.
External Curveball: EMI From the Substation
At 01:42, while the aircraft was 1.2 km Beyond Visual Line of Sight (BVLOS), the telemetry stream dropped from -70 dBm to -95 dBm and RC RSSI flashed amber. The pilot’s first instinct was to abort, but the FlyCart 30’s adaptive OFDM radio already stepped down to 866 kbps and held the encrypted VPN.
A quick spectrum scan showed a 14 dB spike at 2.435 GHz—exactly the band used by a nearby 90 kV/25 MVA substation cooling-pump VFD. The fix: tilt the two diversity antennas 3 cm aft to place the carbon-fiber boom between the interference source and the antenna phase center. Link margin jumped back to -40 dBm, and the mission continued without a single packet loss.
Expert Insight
“We’ve seen VFD harmonics ride the steel lattice like a broadcast antenna. A carbon boom acts as a 30 dB shield at 2.4 GHz when you park the antenna inside its shadow cone. Takes ten seconds, saves the sortie.”
—Laura M., Grid UAS Inspector, 1 800 flight hr on live 380 kV
Technical Deep Dive: Why the FlyCart 30 Never Flinched
1. Payload-to-Weight Ratio
At 30 kg take-off payload and 49 kg AUW, the ratio sits at 0.61—almost double that of typical camera-lift platforms. The extra headroom let us hang 25 kg of de-ionised wash + 5 kg pressurised tank and still lift 3 kg emergency reserve without touching the battery redline.
2. Dual-Battery Redundancy
Two 2 200 Wh hot-swappable packs run in parallel through independent BMS lanes. When cell #11 in Pack A dipped to 3.55 V during the weather hold, Pack B automatically shouldered 62 % load; voltage sag never crossed 0.2 V, keeping the spray pump RPM within ±3 %.
3. Winch System for Instant Grounding
Wind shear spiked from 8 m s⁻¹ to 15 m s⁻¹ at 120 m AGL. Instead of over-flying the tower set, the operator hit “Winch Lower”. The 30 kg payload touched down in 38 s, tether auto-detached, and the aircraft climbed away at 5 m s⁻¹ to wait for the gust front to pass. No human within 30 m of the right-of-way, circuit still hot.
4. IP55 in Monsoon Humidity
Night RH hovered at 94 % and salt-laden fog coated everything. The FlyCart 30’s IP55 labyrinth vents and conformal-coated ESCs kept internal RH below 65 % (logged). No corrosion on the gold-plated winch contacts next morning.
Performance Snapshot: Night Power-Line Spraying
| Metric | FlyCart 30 | Conventional Bucket Truck |
|---|---|---|
| Mission time (6 km) | 1 h 47 min | 5 h 30 min (3 outage blocks) |
| Customer outage minutes | 0 min | 180 min |
| Personnel in risk zone | 0 | 2 linemen at 220 kV |
| Energy cost (battery) | 4.4 kWh | 55 L diesel |
| Weather hold recovery | 18 min hover reserve | N/A—truck must stow |
| EMI mitigation | 3 cm antenna tilt | N/A—manual wash unaffected |
Route Optimization: Flying the Catenary in the Dark
We imported the PLS-CADD tower file into UgCS, set a 3 m horizontal and 5 m vertical buffer from the conductor, and let the optimiser build 180 m racetracks with 12 m altitude steps. Night LiDAR verified conductor sag at 28 °C; waypoints auto-shifted 0.4 m vertically to keep spray tip >2 m from silicone insulator sheds. Total flight plan: 312 waypoints, 7.4 km air-distance vs 6 km line-length—only 23 % overfly, well inside the <30 % BVLOS efficiency KPI.
Common Mistakes to Avoid on Night Power-Line Jobs
Skipping the EMI survey
Substations, railway 25 kV feeders, and AM broadcast towers all create 2.4 GHz harmonics. Run a SAF Spectrum Compact the afternoon before; mark hot spots on the map and pre-plan antenna tilts.Flying with a single battery “to save weight”
Night spraying is time-critical; weather often closes in. Dual-battery redundancy gives you the 18 min buffer that turns a diversion into a mission complete.Ignoring winch pre-load checks
The winch line must be pre-tensioned to 8 kg so payload descent starts instantly. A slack line adds 8–10 s of free-fall jerk that can swing the load into the tower steel.Overfilling the tank to “maximise litres per sortie”
Leave ≥5 % ullage; silicone expands 2 % per 10 °C and night ops see 15 °C temperature drop. Over-fill risks rupturing the IP55 seal around the pump plate.
Post-Flight Debrief: What We Logged
- Battery cycle count: +1 on each pack, 97 % SOH retained
- Winch motor temp: peak 42 °C (ambient 26 °C)
- Spray uniformity: 1.2 mg cm⁻² average, σ = 0.14 (ISO 60507 pass)
- Link quality: 0 dropped packets, -40 dBm minimum after tilt fix
- Ground time: 6 min for battery swap, tank refill, and data download
Frequently Asked Questions
Q1: Can the FlyCart 30 spray in light rain?
Yes. The IP55 rating protects against low-pressure water jets from any direction. We flew through 0.4 mm h⁻¹ drizzle; all electronics stayed dry, and the silicone adhered normally once insulators surface-wetted.
Q2: How close can I fly to live conductors without corona discharge damage?
Maintain ≥2 m from 220 kV phase conductors at 50 Hz. The FlyCart 30’s carbon shell is RF-transparent, but the metal winch drum can arc if inside 1 m. UgCS geofence defaults keep you safe.
Q3: Does dual-battery redundancy mean I can hot-swap during flight?
No. The packs are hot-parallel, not hot-swappable in air. The advantage is automatic load sharing and fault isolation; if one pack fails, the other keeps the aircraft aloft with ≥60 % capacity.
Next Steps
Ready to map your own BVLOS power-line workflow? Contact our team for a site-specific EMI survey and route-optimization script built for UgCS Enterprise. If your corridor exceeds 10 km, ask about the FlyCart 50—same winch system, 50 kg payload, and redundant LTE/5G modem for deep BVLOS.