FlyCart 100 at 3,800 m: How 100 kg Night-Peak Deliveries Still Hit 92 % Battery Reserve
FlyCart 100 at 3,800 m: How 100 kg Night-Peak Deliveries Still Hit 92 % Battery Reserve
TL;DR
- A 100 kg payload-to-weight ratio and dual-battery redundancy let the FlyCart 100 land with 92 % reserve after a 14 km BVLOS night sortie above the tree line.
- Route-optimization logic shaved 18 % off climb power by hugging ridgeline updrafts—saving 2.1 kWh per peak rotation.
- A quick antenna pitch tweak neutralized stray EMI from an alpine relay station, keeping the link at -68 dBm without rebooting the mission.
Night Ops on the Ridge: Why Battery Efficiency Becomes Mission-Critical
Above 3,000 m, air density drops 30 % and every extra watt matters. The FlyCart 100 was tasked to drop 92 kg of radio repeater gear on three knife-edge summits before dawn, then fly back to valley base for a truck departure at 05:30. A single battery swap would have cost the crew 45 min on a freezing ridge—unacceptable for the client’s sunrise deadline. The only viable KPI: land with ≥90 % reserve on every leg.
The aircraft already ships with dual-battery redundancy (2 × 3.2 kWh Li-ion). Yet redundancy alone does not stretch joules; it only hedges against cell failure. To hit the 90 % target we had to squeeze four levers:
- Route optimization that factors real-time wind.
- Payload-to-weight ratio discipline (leave the fancy pelican case behind).
- Winch system hover time capped at 20 s.
- Pilot-triggered Eco-Thrust map that caps rotor RPM at 85 % during cruise.
Technical Snapshot: FlyCart 100 vs. Conventional 80 kg-Class Delivery UAV
| Spec | FlyCart 100 (Night-Peak Config) | Industry 80 kg VTOL |
|---|---|---|
| Max payload | 100 kg | 80 kg |
| Empty weight (incl. winch) | 62 kg | 68 kg |
| Payload-to-weight ratio | 1.61 | 1.18 |
| Dual-battery capacity | 6.4 kWh | 5.0 kWh |
| Hover power at 3,800 m | 7.8 kW | 9.4 kW |
| Cruise power @ 18 m/s | 4.1 kW | 5.7 kW |
| Emergency parachute descent | 4.5 m/s | 6.2 m/s |
| BVLOS link margin (with H-pol) | -68 dBm | -78 dBm |
| Reserve after 14 km mission | 92 % | 71 % |
The EMI Curveball: 30 Seconds to Save the Mission
02:17 a.m.
Three kilometres out, the telemetry window suddenly jitters—packet loss 12 %, uplink SNR drops 8 dB. Cause: a VHF relay station on the same ridge blasting 50 W at 159 MHz. The FlyCart 100’s radio is hardened, but the vertically-polarized antenna was catching side lobes.
Pro Tip: Carry a 90° elbow SMA in your flight kit. Pitching the antenna to horizontal polarization bought us 10 dB of isolation and restored the link to -68 dBm—all without breaking the mission clock. Total downtime: 0 s.
Anatomy of an 18 % Power Save: Route Optimization in Terrain Wind
The alpine night generates katabatic flow: cold air slides down slopes at 3–5 m/s. Instead of climbing straight over each peak, the FlyCart 100’s optimizer hugged the lee side, using the downdraft as a free sink rate during descent and avoiding the updraft core on the windward wall.
- Predicted track (straight-line): 6.2 kWh
- Actual optimized track: 5.1 kWh
- Net saving: 1.1 kWh (18 %)
That margin is what filled the reserve tank to 92 %, letting us delete a planned en-route hover check and still land 6 min ahead of schedule.
Common Pitfalls at High-Altitude Night Drops
Ignoring battery pre-heat
Cells below 10 °C shed 15 % capacity. We kept packs at 20 °C with 12 V heating sleeves powered from the field inverter.Excessive winch hover
Every 10 s of hover at 3,800 m burns 0.13 kWh. Pre-rig the sling so the load releases in ≤20 s.Flying BVLOS without redundant ADS-B
Tourist helicopters occasionally ferry oxygen bottles at night. The FlyCart 100’s ADS-B Out and strobe package kept us visible; still, we filed a NOTAM for the ridge window.Forgetting barometric offset
QNH dropped 8 hPa during the sortie. The flight controller auto-compensated, but manual pilots must reset altimeter references to avoid 30 m drift into rock face.
Winch System: Faster Drop, Lower Draw
A 100 kg payload sounds heavy until you realise the carbon-fibre winch adds only 3.8 kg to the airframe. We spooled 35 m of UHMWPE line in 8 s, delivered the repeater, then retracted in 10 s. Total high-power draw: <0.25 kWh, half of what a 60 s vertical landing would have cost on the uneven summit.
Regulatory & Safety Layer
- BVLOS waiver: pre-approved under EU SORA 2.5 with GESAs mitigated by parachute and geo-cages.
- Emergency parachute: ballistic-deployed, 4.5 m/s descent; tested the previous week at -18 °C with no fabric stiffening.
- Dual-battery redundancy: if one pack hits <15 %, the controller automatically isolates it and continues on the healthy pack—no mid-air shutdown, no payload jettison.
Frequently Asked Questions
Q1: Can the FlyCart 100 really maintain a 100 kg payload at 3,800 m on a 20 °C night?
Yes. Air density is 0.95 kg/m³, so rotors spin 7 % faster, but the 1.61 payload-to-weight ratio leaves 38 % thrust margin in the ESC curve—well inside safety envelope.
Q2: Does the winch work in icing conditions?
The UHMWPE line is hydrophobic; tests at -12 °C with 85 % RH showed <1 mm rime accretion and no tangling. Heated spool option available for -30 °C ops.
Q3: How loud is the FlyCart 100 during night cruise?
58 dB(A) at 50 m slant range—below most rural background. Perfect for noise-sensitive alpine fauna zones.
Ready to Run Your Own Peak-Ridge Supply Chain?
Mapping 100 kg drops at night no longer means choosing between payload and battery life. Contact our team to model your exact elevation, climate, and payload matrix; we’ll ship a turnkey FlyCart 100 config—including the winch system, dual-battery redundancy, and route-optimization license—ready to fly BVLOS within weeks. For lighter medical payloads, also review the FlyCart 30 variant (30 kg, foldable rotor booms).
Fly smart, land rich—in reserve power and operational budget.