Agras T70P on a Wind-Turbine SAR Mission: How Dual Radar & 70L Tank Tamed Post-Rain Mud and 60m Blades
Agras T70P on a Wind-Turbine SAR Mission: How Dual Radar & 70L Tank Tamed Post-Rain Mud and 60m Blades
TL;DR
- The IPX6K-rated Agras T70P lifted 70kg spray payload through ankle-deep sludge, then switched to 80kg spread mode for rapid lime marking of safe walking corridors—no manual rappel rigging required.
- Active Phased Array Radar + Binocular Vision delivered centimeter-level precision at <1m stand-off** from a rotating 60m blade, keeping the team below turbine-shadow turbulence while maintaining **RTK Fix rate >99%.
- Dual Atomization cut spray drift to <2% in 25km/h rotor wash, letting medic crews climb a dry, de-iced nacelle ladder 18min after last pass—four-times faster than ground-based boom deployment.
From Swamp to Sky—Why a Crop-Sprayer Became the SAR MVP
Last spring I guided a rescue crew across a wind-farm access road that had turned into a 12% slope clay slick after 48h of rain. The turbine in question sat at the ridgeline; a maintenance tech had slipped inside the nacelle and needed evacuation. Traditional ATVs bogged down within 30m, and a winch truck would have torn the fragile soil crust, risking tower tilt. We needed two things in one airframe:
- Rapid de-icing of the blade root so medics could lash a safe hoist point.
- A visual “breadcrumb” spread pattern so boots could ascend without sinking.
The Agras T70P—normally my go-to for orchard fungicide work—answered both calls in a single battery cycle.
Anatomy of a SAR Obstacle Field
Muddy Footprint & Dynamic Obstacles
- Ground bearing strength: <40kPa** → footprint sink **>15cm per step.
- 1.5m rotor-tip deflection at 18rpm → obstacle envelope changes every 3.3s.
- 5G base-station on tower shoulder → EMI spikes up to –85dBm, enough to drop consumer GNSS.
Why Consumer Drones Wash Out Here
Standard quads lose RTK lock under EMI, and optical cameras misread wet composite blades as sky—classic false-negative. The T70P’s Active Phased Array Radar ignores optical trickery; it maps Ka-band reflections in real time, giving 360° obstacle density at 0.1s refresh.
Technical Deep Dive—Specs That Matter for Vertical SAR
| Parameter | Field-Measured Value | SAR Impact |
|---|---|---|
| Tank / payload swap time | <45s | Switch from de-ice spray to lime granules without tools |
| Swath width (dual atomizer) | 7–11m @ 3m AGL | Covers blade chord in two passes, halves exposure time |
| RTK Fix rate (EMI present) | 99.3% (24min log) | Maintains centimeter-level precision for repeatable stand-off |
| Radar detection distance (blade tip) | 0.7–40m adjustable | Triggers braking at 1m, keeps rotor wash outside spray plume |
| Nozzle calibration resolution | 0.01L min⁻¹ | Limits run-off on 35° nacelle roof, prevents secondary ice |
| Battery endurance (hover + spray) | 15min with 70kg load | Two full blade roots + spread corridor per pack |
| IPX6K rating | Certified | Survived direct hose-down by safety crew post-flight |
Flight Pattern—From Take-off to Medevac Call
1. Pre-Flight: Nozzle Calibration in Wind Shadow
I dialed TTI110-04 nozzles to 0.8L min⁻¹ at 4bar, verified with graduated cylinder. Target droplet VMD: 180µm—large enough to resist spray drift, small enough to melt rime ice. With rotor wash at 25km/h, this setting kept <2% drift 10m downwind (fluorescein tape test).
2. RTK Base Placement
Placed base 350m south on bedrock, 18km baseline to CORS. Achieved RTK Fix rate >99% within 30s, even with turbine EMI. Multispectral mapping later showed our base footprint disturbed <0.02ha—negligible vs. truck track of 0.3ha.
3. Spray Run—Dual Atomization Engaged
- 8m s⁻¹ forward speed, 3m AGL, 60% overlap, giving 99% chord coverage.
- Radar locked blade at 1.2m; aircraft auto-leaned 8° nose-in to counter drift vector.
- Entire leading edge de-iced in 3min 42s, ambient 2°C, 85% RH—no re-freeze observed.
4. Granule Spread—Marking Safe Footprints
Swapped tank for 80kg lime spreader in 38s. Set swath width 6m, 1kg m⁻². Lime layer raised soil bearing strength to >90kPa, allowing four rescuers to ascend with <1cm sink.
Pro Tip
When spreading on a slope >10°, program T70P to fly contour lines, not up-down. This keeps disc speed constant and prevents downhill over-delivery that can bury shoe cleats—learned that the hard way on a 2019 vineyard mudslide job.
Common Pitfalls—What to Avoid in Wind-Turbine SAR
Ignoring EMI Gradient
Never trust a single RTK health bar. Log Fix rate for >2min at hover before committing to pattern; if it dips below 98%, offset base station another 100m perpendicular to tower.Over-Flying Blade Tip
Radar braking defaults to 1m. In demo mode I’ve seen crews push to 0.5m for “cool footage.” Tip vortex can roll the aircraft; keep ≥1m and let atomizer reach do the work.Wrong Nozzle for Cold Temp
04 orifice blocks at 0°C if glycol content <25%. Use 05 and drop pressure to 3bar instead—same flow, lower freeze risk.Forgetting Post-Flight Rinse
De-ice glycol is hygroscopic; if you land and pack up, crystals will coat the pump by morning. Flush 5L clean water through boom within 30min of shutdown.
Expert Insight—Data-Driven Safety Margin
Expert Insight
We tethered a MicaSense ten-band unit under the T70P for a quick multispectral mapping pass post-mission. NDVI of the lime trail showed +0.12 vs. untreated mud—proof the spread was even and thick enough to reflect solar load, speeding surface dry-out. That index snapshot went to the site geotechnical engineer; he cleared heavy-vehicle access 4h earlier than planned, saving one full day of crane standby.
Frequently Asked Questions
Q1: Can the Agras T70P operate in light rain during SAR?
A: The IPX6K rating handles pressurized water jets from any angle, so drizzle is fine. Avoid freezing rain >1mm h⁻¹—ice accretion on prop cuffs can upset thrust balance.
Q2: How low can radar keep the aircraft from a curved tower wall?
A: Adjustable down to 0.5m. For SAR we recommend 1m minimum; the radar’s ±2cm accuracy still gives you 30cm safety buffer after GPS jitter.
Q3: Is one battery enough to both de-ice and spread markers on a 65m turbine?
A: Yes. Expect 6–7min for two blade roots (de-ice) plus 3min for a 100m lime corridor—total ~11min. A fresh DB1560 yields 15–20min with 70–80kg payload, leaving 4min reserve for contingency hover.
Ready to integrate the T70P into your emergency-response fleet or scale it back to everyday spraying? Contact our team for a consultation on nozzle kits, spreader cones, and RTK base layouts tailored to your terrain.