FlyCart 30 Night-Time Wind-Turbine Inspection: 30 kg Payload Optimization That Beats 40-m Knots & Curious Barn Owls

TL;DR

The FlyCart 30 lifts 30 kg of inspection gear on a dual-battery redundancy pack, cruises BVLOS for 16 km per leg, and still lands with >20 % reserve—no payload-to-weight ratio penalty.
IP55-sealed carbon frame, winch system, and radar-based sense-and-avoid let the aircraft hover inside a 40 m rotor arc while a startled barn owl dives past at 18 m/s—no mission abort.
Route-optimization scripts cut turbine-cycle time from 38 min to 24 min per unit, saving one full crew night and >9 L of genset fuel on a six-tower string.

Why Night Inspections Demand Payload Discipline

Wind-farm owners now book drone slots at 02:00–05:00 to avoid curtailment and capture hot spots before morning ramp-up. That sounds simple until you factor in:

18 °C dew-point decks that ice sensors
25 m·s⁻¹ tip-speed turbulence
A maze of 33 kV collection lines feeding into the substation

Every extra kilogram of payload burns battery and forces wider exclusion zones. The FlyCart 30’s 30 kg certified hook load plus winch system keeps the aircraft 12 m above nacelle height—outside the rotor disc but close enough for sub-millimetre thermal imaging.

Expert Insight
"We used to sling a Phase-One iXM-100 and a gas-sniffer together—4.2 kg plus gimbal. By switching to the FlyCart’s integrated winch system we removed the heavy drop-cage, clawed back 1.8 kg, and gained 3 min hover time. That margin let us double the turbine count before battery swap."

Technical Snapshot: FlyCart 30 in Nocturnal Wind Farms

Parameter	FlyCart 30 Spec	Scenario Impact
Max payload (dual battery)	30 kg	Carries FLIR A8580 (3 kg), corona camera (4 kg), laser methane sensor (2 kg) plus 600 m winch cable (9 kg) with 12 kg reserve for auxiliary battery heaters
IP rating	IP55	Continues mission after 15 min side-ways rain at 12 m·s⁻¹—no electronics re-boot
Redundancy	Dual-battery, dual-GNSS, dual-IMU	When a 33 kV line under the substation arced, RF noise spiked to -85 dBm; aircraft auto-switched to IMU-2 and completed BVLOS segment
Winch speed	0.8 m·s⁻¹	Lowers sensor through 40 m rotor sweep in 50 s—keeps aircraft above gust layer
Operating temp	-20 °C to 50 °C	Heater pads on batteries maintain >15 °C cell temp at -12 °C ambient, retaining >92 % capacity
Max wind (steady)	12 m·s⁻¹	Gust to 15 m·s⁻¹ recorded; aircraft tilt peaked 28° yet gimbal SD stayed <0.1°

Payload-to-Weight Ratio: The 0.42 Sweet Spot

Aircraft empty mass is 41 kg with dual batteries. Add 30 kg payload and you land at 71 kg—a 0.42 payload-to-weight ratio. Anything above 0.45 triggers automatic power-margin lock in the flight core, throttling horizontal speed to 5 m·s⁻¹. Stay below the line and you keep 10 m·s⁻¹ cruise, critical for covering 2 km spacing between turbines before offshore breeze picks up.

Route Optimization in Practice

Pre-load substation SCADA data to tag turbines with >2 °C bearing rise.
Sequence flight so that 80 % of legs are cross-wind, reducing hover time by 22 %.
Drop winch sensor on the leeward side—turbulence -30 % compared to windward approach.

Night result: six-turbine string completed in 2 h 24 min instead of 3 h 50 min, saving one full tank of diesel for the chase-boat genset.

Wildlife & Obstacle Encounter: Barn Owl at 18 m·s⁻¹

At 01:47 we were winching past the 92 m blade when a barn owl stooped from the nacelle roof, diving through the rotor disc at 18 m·s⁻¹. The FlyCart’s omnidirectional radar flagged a 0.4 m² object at 28 m, triggered a 2 m climb and 1.2 m lateral offset, then resumed winch path—all within 3.4 s. Mission continued; data gap 0 s. No other aircraft in the sub-25 kg class offers that level of sense-and-avoid without add-on pods that would have pushed us into the next weight category.

Common Pitfalls & What to Avoid

Over-loading the winch cable
Cable plus sensor must stay under 12 kg to keep dynamic tension <350 N in gusts. A heavy lens heater once took us to 13.4 kg, causing 0.9 m swing that blurred IR frames.
Flying with cold-soaked batteries straight from the truck
Cells at -5 °C sag to 3.55 V under hover load, forcing an early RTH even though SOC reads 45 %. Always pre-heat to 15 °C using the integrated warming plate (18 W per pack).
Ignoring substation RF wash
A 33 kV vacuum breaker can push -60 dBm at 1.5 GHz, enough to blind some GNSS modules. Map breaker schedules and time winch descents between switching events.

Regulatory & Safety Checklist for BVLOS Night Ops

File SAIL III risk assessment—include winch failure mode descending at 0.8 m·s⁻¹ with emergency parachute descent at 4 m·s⁻¹ if aircraft bus fails.
Equip crew with thermal binoculars to maintain “see and avoid” for any non-cooperative traffic outside radar arc.
Program geo-fence at 1.5 × rotor tip height; FlyCart will auto-rotate away instead of triggering parachute, saving you a 2 km retrieval swim in the North Sea.

Frequently Asked Questions

Q1: Can the FlyCart 30 maintain 30 kg payload in a 12 m·s⁻¹ gust while winching?
A1: Yes. The winch system locks cable tension at 350 N and the flight controller tilts up to 30°, but lift reserve stays >18 % thanks to dual-battery voltage stability.

Q2: Does IP55 protect the winch drum from salt-spray at 0 °C?
A2: The drum is sealed to IP55 and grease-filled; 72 h salt-fog testing showed no corrosion. Still, rinse with fresh water post-flight to keep cable strands salt-free.

Q3: How accurate is the route-optimization algorithm over water where turbine GPS coordinates shift with tide?
A3: Upload RTK base station on the service platform; algorithm compensates for ±1.2 m tidal deck movement, keeping sensor offset error <0.05 m relative to blade.

Next Step: Cut Your O&M Budget Tonight

Ready to swap risky rope-access climbs for repeatable 30 kg sensor drops? Contact our team for a site-specific payload map and see how the FlyCart 30 stacks against the 40 kg class without their Part 107 weight penalties. If your farm strings exceed 8 km, ask about the FlyCart 50 prototype—same IP55 backbone, 50 kg hook, scheduled for field pilots Q3.