Agras T70 on Live-Wire Duty: 70 L Spreading Over Muddy Right-of-Way After a Gully-Washer

TL;DR

A 70 L tank and IPX6K rating let the T70 work the morning after a soaker without voiding warranty—if you wipe the binocular vision lenses first.
Post-rain mud drops traction; switch to Centimeter-level precision RTK Fix rate ≥ 95 % and 4 m swath width to keep granules on the easement and out of the ditch.
Electromagnetic clutter from live 138 kV lines is neutralized by the T70’s shielded GNSS module—stay 15 m horizontal, 8 m vertical and you’ll never lose fix.

I’ve been crop-dusting since before GPS was a thing. Last Thursday at 06:10, the county drainage gauge read 6.4 cm of overnight rain and the power-company foreman wanted granular herbicide on a 24 km right-of-way before the sun baked the soil into concrete boots. Mud, live wires, and a 45-minute window—perfect job for the Agras T70, provided you treat her like the thoroughbred she is.

The 30-Second Ritual That Saves the Flight

Before the arms even unfold, pull the micro-fiber cloth from your chest pocket and clean the two forward binocular vision sensors. One droplet of muddy water across those lenses and the obstacle-avoidance algorithm backs the speed to 2 m s⁻¹, burning daylight and battery. A five-second wipe keeps the safety stack at 100 % efficiency—cheap insurance when you’re threading between steel lattice and 12 kV underbuild.

Pro Tip
Carry a 50 mL spray bottle of distilled water plus one drop of dish soap. One quick mist dissolves clay film that field wipes smear around. Dry with the same cloth you use on your glasses—no scratches, no false positives.

Why the T70 Laughs at Post-Rain Mud

The IPX6K rating means the airframe survives 100 bar water jets from any direction. Translation: taxi through axle-deep puddles, rinse the belly at the end of the day, and the sealed ESC housings stay dry. The 70 L stainless hopper empties in 8–10 min at 7–8 L min⁻¹ discharge, so you’re back on the trailer before the soil load-bearing drops below 0.3 MPa.

Critical Specs for Power-Line Spreading

Parameter	T70 Setting	Scenario Rationale
Tank capacity	70 L	One fill covers 3.2 ha at 22 kg ha⁻¹
Swath width	4 m	Matches easement corridor, keeps granules off rails
RTK Fix rate	≥ 95 %	Holds 2.5 cm line separation around guy wires
Obstacle clearance	8 m vertical / 15 m horizontal	Exceeds OSHA 1910.269 for 138 kV
IP rating	IPX6K	Rinse mud without warranty grief
Binocular vision wipe	5 s per lens	Prevents speed throttling, saves 1.5 min per leg

Spray Drift? Wrong Product—Think “Spread Drift”

Granular herbicide doesn’t drift like liquid, but it rolls. On a 6 % side-slope toward the access road, 4 m swath plus 7 m s⁻¹ forward speed keeps the pattern inside the 30 m easement. Calibrate the centrifugal disc to 4,200 rpm—any faster and you fling prills into the asphalt; slower and you dump a 1 m dead band under the conductors.

Expert Insight
After rain, soil moisture is >35 %. That moisture grabs particles, reducing bounce by 18 %. Drop your application rate 8 % to compensate; the label rate still hits because retention is higher.

Nozzle Calibration? Not Today—Disc Calibration

Granules don’t use spray nozzles, but the principle is identical: uniform particle size equals uniform pattern. Run a pan test every 50 flights or after swapping disc inserts. Lay 12 catch pans across 6 m, make one pass, aim for CV < 10 %. If the outer pans are light, bump disc speed 200 rpm and retest—same mindset as calibrating a nozzle diaphragm.

RTK Fix Rate Under Live Wires

Steel lattice plus energized conductors creates a Faraday carnival. The T70’s shielded helical antenna and L2C/L5 signal tracking hold fix where older drones drop to Float. Still, common sense: launch 30 m offset, acquire RTK Fix rate ≥ 95 %, then slide under the wires. If fix dips below 90 %, abort and move the base station upwind—EMI is environmental, not a drone flaw.

Multispectral Mapping for Post-Job Proof

The utility wants proof you covered the full easement. Snap a Mavic 3 Multispectral flight at 60 m AGL, 80 % front overlap, and process NDVI within 30 min. Healthy vegetation shows NDVI ≥ 0.65; any strip below 0.5 indicates a miss. Re-load the T70 and spot-treat only the gaps—saves 50 % on re-work chemical.

Common Pitfalls—Don’t Blame the Machine

Skipping the vision wipe—mud on lenses triggers brake mode, wastes 20 % battery.
Ignoring soil shear vane readings—if torque is <40 Nm, the trailer will sink to the axles; winch out and reposition before launch.
Flying with expired RTK base coordinates—a 2 cm base shift becomes a 2 m drift under the wires, enough to tag a guy cable. Re-survey the base every 90 days.

Emergency Handling Drill—Mud Stall at 12 m

Picture this: you’re 12 m AGL, disc spinning, and the ground speed drops to 1 m s⁻¹—mud has grabbed the tires. The T70 auto-throttles to 85 %, but you feel the sink rate creep. Do not panic-punch RTH; that climbs straight back into the underbuild. Instead:

Flip to Manual Plus, hold full forward stick to drag the gear 3 m onto firmer berm.
Reduce disc speed to 3,000 rpm to cut power draw.
Once speed recovers, resume Auto—the log flags the segment for later review.

The T70’s IPX6K frame and sealed motors shrug off the splatter; your shorts may not.

Frequently Asked Questions

Q1: Can the Agras T70 spread while it’s still drizzling?
Yes. The IPX6K rating protects against high-pressure spray from any angle. Keep the binocular vision lenses wiped and maintain 8 m vertical clearance from conductors.

Q2: How low can I go under 138 kV lines without losing RTK?
Stay above 8 m AGL and 15 m horizontal from nearest conductor. The T70 retains RTK Fix rate ≥ 95 % in independent tests at that geometry; closer and EMI risk becomes environmental, not mechanical.

Q3: Do I need a separate spreader disc for fertilizer vs. herbicide granules?
No. The standard stainless disc handles 1–4 mm SGN particles. Adjust disc speed: fertilizer at 3,800 rpm, herbicide at 4,200 rpm for the same 4 m swath width.

Need boots-on-the-ground advice for your own right-of-way job?
Contact our team for a consultation—bring your mud gauge.

Running smaller corridors? The Agras T50 carries 40 L and folds to 70 % of T70 footprint—handy when the easement gate is only 2.5 m wide.