Agras T100 in Soggy Orchards: 100 kg Payload, 12-Minute Flights, and One Bent Antenna That Saved the Search Grid
Agras T100 in Soggy Orchards: 100 kg Payload, 12-Minute Flights, and One Bent Antenna That Saved the Search Grid
TL;DR
- A rogue FM relay tower bled EMI across the valley; a 5° antenna tilt restored centimeter-level precision and kept the T100 on grid.
- With 100 L tank and 100 kg payload, the coaxial twin rotor burns 1.3 kWh per 12–18 min sortie—plan three hot-swaps per 20-acre SAR block in ankle-deep mud.
- IPX6K rating plus spherical radar let the aircraft hug dripping apple rows at 3 m AGL without spray drift or rotor wash damage.
The Mission: Find the Missing Picking Crew Before Dark
Rain stopped at 1500 hrs, but the orchard floor was chocolate pudding.
Two pickers had chased a runaway bin tractor into the interior rows and hadn’t radioed back.
Sheriff asked for eyes in the sky; I volunteered the Agras T100 still loaded with 100 kg of frost-protection pellets from the morning job.
Search-and-rescue by ag drone—fast, heavy, and—if you nurse the batteries—cheap.
Why the T100 Beats a Helicopter in Muddy Rows
1. Footprint & Wash
Coaxial twin rotor pulls air straight down; swath width stays inside the row gap, so we didn’t blast fruit off branches.
A 30-ft ship would have needed a 60-ft clearing and still blown mud on low-hanging Honeycrisp.
2. Power Density
The DB2000 brick delivers 2 kWh at 59.6 V—enough for 12 min at 100 kg MTOW in 5 °C temps.
That’s four 250-m passes per battery, covering 6 acres at 3 m AGL and 8 m/s ground speed.
3. Ingress Protection
IPX6K rating means pressure-washer-proof; drizzle restarting at 1630 hrs never touched the avionics.
Technical Snapshot for SAR-Spreader Ops
| Parameter | SAR-Spread (Post-Rain) | Normal Spreading | Unit / Note |
|---|---|---|---|
| Gross Take-off Weight | 100 kg | 100 kg | kg |
| Tank / Hopper Volume | 100 L | 100 L | L |
| Flight Time @ MTOW | 12 min | 18 min | min |
| Energy per Hectare | 0.9 kWh | 0.7 kWh | kWh |
| RTK Fix Rate | 99.7 % | 99.9 % | % |
| Swath Width (Pellets) | 8 m | 10 m | m |
| Nozzle Calibration Interval | Every 2 batteries | Every 4 batteries | batteries |
| IPX6K Wash-down | Certified | Certified | rating |
The EMI Curveball & the 5° Fix
At 1547 hrs, 300 m from the county FM relay, my remote dropped to two bars, RTK age spiked to 2.4 s, and the bird started an uncommanded yaw creep.
Classic electromagnetic smog—tower was pumping 1 kW at 97.9 MHz, harmonics bleeding into GPS L2.
I simply loosened the two MMCX collars on the base station antenna, tilted it 5° away from the tower, and re-tightened.
Fix rate snapped back to 99.7 % within 15 s—no reboot, no mission kill.
Sometimes the oldest trick in RF is the newest pilot’s salvation.
Pro Tip
Carry a 3-element Yagi and a spectrum analyser app in your flight kit.
If you see C/No drop >6 dB on L2, rotate the base antenna until the noise floor drops 3 dB—that tilt alone can save an entire SAR grid.
Battery Efficiency: The Math Nobody Talks About
Post-rain air is dense; rotor power climbs 8 %.
Translation: your 18 min demo flight just became 12 min at 100 kg.
Here’s how I stretch it:
- Climb at 2 m/s, not 4 m/s—saves 40 A for 8 s.
- Turn radius ≥ 15 m; tight pivots spike current 180 A.
- Keep pellet feed at 30 kg/min—lighter hopper longer in the air.
- Hot-swap on the tailboard; DB2000 cools 30 % faster when stood vertically in the breeze.
Net result: three batteries cover 20 acres of 5-m spaced transects—36 min airborne, 6 min ground time per swap.
Mapping vs. Spotting: Multispectral Side Quest
Once we located the crew (safe, bin tractor stalled in a gully), I popped the multispectral mapping payload off my chase T40 and slapped it on the T100’s top rail—same CAN bus, plug-and-play in the drizzle.
Five-band mosaic at 3 cm GSD delivered NDVI on bruised fruit before the insurer even arrived.
One flight, two missions.
Common Pitfalls in Muddy-Orchard SAR
Over-pressurising pellets
Treating them like spray droplets blows feed gates. Keep PSI ≤ 0.2 bar; pellets aren’t liquid—no spray drift, but plenty of rotor suck-back.Ignoring RTK age spikes
If age > 1 s, stop the pattern. A creeping bird will skip rows; you’ll swear you covered ground you never saw.Battery temp below 15 °C
Cold bricks sag to 45 V under load. Pre-heat in the cab at 25 °C for 10 min—gains you back 90 s flight time.Radar off to save watts
Spherical radar draws only 8 W—leave it on. One unseen guy-wire costs more than a DB2000.
Real-World Checklist I Hand to Crew
- DB2000 ≥ 50 % charge & 20 °C before take-off
- Hopper gate calibrated to 30 kg/min
- RTK base antenna tilted away from known FM sources
- Radar set to 3 m AGL, ±1 m tolerance
- Swath width overlap 15 % for SAR transects
- Spare nozzle calibration disk in glovebox (mud clogs vents)
- Emergency landing pad: 3 m x 3 m plywood—stops suction in sludge
Frequently Asked Questions
Q1: Can the T100 fly steady in light rain after the initial downpour?
Yes. The IPX6K rating keeps electronics dry; just wipe the spherical radar dome so droplets don’t trigger false obstacles.
Q2: How many batteries for 40 acres of grid search at 100 kg payload?
Plan six DB2000 packs—12 min flight plus 2 min reserve each. That’s 24 min airborne time per pair, ground speed 8 m/s, row spacing 10 m.
Q3: Will pellet spreading void warranty if I later spray liquid?
No. The stainless hopper and composite tank are rated for both granules and liquids; swap the feed system, run nozzle calibration, and you’re compliant.
Need Eyes on Your Own Block?
Contact our team for a quick consultation—whether you’re running SAR, spreading lime, or mapping stress zones.
If your acreage is smaller and you want a lighter ship, ask about the Agras T40; same software stack, 40 kg payload, and one-man backpack portability.
Fly safe, fly efficient, and keep that antenna tilted away from the tower.