Tethered UAV Firefighting Solution: DJI FC300 + 42 kW Ground Power System
How Kitefly Tethered's high-power tethered drone system breaks the altitude, endurance, and payload limits that have long constrained aerial firefighting, high-rise suppression, wildfire monitoring, and hazmat emergency response.
Overview: Redefining the Aerial Firefighting Market
As urban high-rise fires, wildland-urban interface incidents, and chemical plant emergencies become increasingly common worldwide, the limitations of conventional firefighting equipment are being exposed. Aerial ladder trucks top out at 50–100 meters. Battery-powered drones provide only 20–40 minutes of flight time. Standard UAV platforms simply cannot carry the payload needed for suppression systems, communication relays, or heavy rescue equipment.
The integration of the DJI FC300 heavy-lift UAV platform with Kitefly Tethered's 42 kW ground power system delivers a purpose-built solution that addresses all three constraints simultaneously — providing unlimited flight endurance, 150 kg payload capacity, and the ability to operate continuously above 150 meters.
Kitefly Tethered (Nanjing Weize Chuangli Electronic Technology Co., Ltd.) is a nationally certified high-tech enterprise founded in 2018 and headquartered in Nanjing, China. With over a decade of tethered UAV power system development, Kitefly Tethered is one of China's earliest and most experienced tethered UAV power solution providers, with more than 30 custom tethered power configurations delivered globally. The company serves global markets across five core verticals: electric tethering, water tethering, wind turbine inspection, aerial display systems (FlyScreen), and heavy-load firefighting.
Contact: susy@tetheredsystem.com | www.tetheredsystem.com
The Three Ceilings Blocking Modern Aerial Firefighting
Emergency responders worldwide face three compounding limitations when deploying aerial assets in active fire scenarios. The FC300 tethered system is engineered specifically to break each one:
Challenge
Conventional Equipment
DJI FC300 + Kitefly Tethered
Altitude Ceiling
50–100 m (aerial ladders & platforms)
150 m+ continuous operation
Flight Endurance
20–40 min per battery cycle
8+ hours continuous hover (24/7 capable)
Payload Capacity
Light drones: 5–10 kg only
Up to 150 kg — suppression, delivery, comms
Core Capabilities: What the FC300 Tethered System Delivers
1. Unlimited Flight Endurance — The Aerial Command Post
The SG50 ground power box converts 380 V AC grid power to high-voltage DC and delivers it continuously through a 150–220 m tethered cable to the FC300 via the VF24 or WF36 onboard power module. This eliminates battery dependency entirely.
▸ 8+ hours of continuous hover — suitable for extended incident command and multi-phase firefighting operations
▸ 24/7 capable power delivery — ground power can be sourced from the grid, generator, or temporary power supply
▸ Full-scene aerial reconnaissance: real-time thermal imaging, wide-area surveillance, and night illumination with zero battery intervention
▸ Communications relay and incident command window — maintains an uninterrupted aerial communications node above the fire perimeter
2. Heavy-Lift Aerial Delivery — Opening the Last-Mile Supply Route
The DJI FC300 platform supports a maximum payload of 150 kg across two operating modes: cargo container delivery and sling-load operations. This transforms the tethered drone from a sensor platform into an active logistics and suppression asset.
Deliverable payloads include:
▸ Rescue equipment — breathing apparatus, rescue rope, forced-entry tools
▸ Emergency supplies — medication, drinking water, satellite communication devices
▸ Suppression payloads — firefighting grenades, dry powder canisters, compact water cannons
In terrain inaccessible to ground vehicles — mountain valleys, collapsed structures, isolated islands — the FC300 provides minute-level precision aerial delivery to frontline responders.
3. High-Altitude Suppression — Breaking the High-Rise Firefighting Barrier
Paired with an integrated tethered water-and-power pipeline, the FC300 system addresses the critical gap above 100 meters where conventional aerial ladder trucks and high-reach water cannons cannot reach.
▸ 150 m+ altitude suppression: precise application of water-based agents and foam suppressants on upper-floor high-rise fires
▸ Multi-axis attack coordination: top-down aerial suppression combined with ground-level operations to cut off fire spread
▸ Window breach and suppression: integrated breach-and-suppress capability to rapidly open rescue corridors
Technical Specifications
Ground Power Unit — SG50 Tethered Power Box
The SG50 is the ground station of the FC300 tethered firefighting system. It converts 380 V AC grid power to 1,000 V DC or 1,400 V DC and delivers it via a high-voltage tether cable to the onboard power module aboard the FC300. Peak output of 40 kW supports the full range of onboard payloads simultaneously.
Parameter
Specification
Product Model
SG50
Input Voltage
380 V AC
Output Voltage
1,000 V DC / 1,400 V DC
Peak Power
40 kW MAX
Cable Length
150 – 220 m
Power Supply Box Weight
49.3 kg ± 1 kg
Cable Box Weight
32.9 kg ± 1 kg
Power Supply Box Dimensions
498 × 472 × 440 mm
Cable Box Dimensions
498 × 471 × 440 mm
Onboard Power Module — VF24 (24 kW Configuration)
The VF24 regulated onboard power module steps down the high-voltage tether input to the precise DC voltage required by the FC300's propulsion system and attached payloads. Compatible with 12S to 28S battery-equivalent voltage configurations.
Parameter
Specification
Product Model
VF24 (Regulated Series)
Input Voltage
800 – 1,000 V DC
Output Voltage
50 / 60 / 73 / 100 V DC (12S / 14S / 18S / 24S / 28S)
Peak Power
24 kW MAX
Weight
9 kg ± 100 g
Dimensions
370 × 223 × 127 mm
Onboard Power Module — WF36 (42 kW Configuration)
The WF36 is the high-power onboard module for maximum-payload operations, supporting up to 42 kW peak output. This is the recommended module for suppression system integration and full 150 kg payload operations.
Parameter
Specification
Product Model
WF36 (Regulated Series)
Input Voltage
1,200 – 1,400 V DC
Output Voltage
40 – 60 V DC (12S / 14S / 18S / 24S / 28S)
Peak Power
42 kW MAX
Weight
11 kg ± 100 g
Dimensions
326 × 280 × 143 mm
Application Scenarios
Urban High-Rise & Super-Tall Building Firefighting
The FC300 tethered system enables rapid deployment within 3 minutes, ascending to operational altitude as fire suppression vehicles arrive on scene. Above 100 m, it provides continuous suppression, aerial search-and-rescue coordination, and a communications relay that reaches through structural interference that ground-level systems cannot penetrate. For fire incidents above the 30th floor, this system represents the only currently available persistent aerial suppression platform.
Wildland & Forest Fire Operations
Extended aerial patrol of fire perimeters — day and night. Infrared fire-point detection and hotspot mapping. Real-time fire behavior analysis for frontline command. Nighttime high-intensity lighting for ground crew safety. Precision aerial delivery of water and suppression agents to forward positions inaccessible by road. The tethered power system enables this capability to run continuously through multi-day fire incidents without crew intervention for battery management.
Chemical Plant & Hazardous Materials Emergency Response
In chemical plant incidents and hazardous materials scenarios, human proximity to the incident zone significantly increases casualty risk. The FC300 tethered system provides a persistent standoff reconnaissance and monitoring capability — thermal imaging through smoke, toxic gas detection payload integration, continuous communications relay for multi-agency coordination, and supply delivery to responders in protective equipment who cannot quickly evacuate for resupply.
Operational & Commercial Value
▸ 3-minute rapid deployment — co-deploys with the first response vehicles on scene
▸ System consolidation — one integrated platform replaces multiple single-purpose aerial assets, reducing procurement and maintenance overhead
▸ Platform integration — compatible with DJI FlightHub 2 / Skydio for multi-aircraft coordinated operations and single-screen command
▸ Scalable deployment model — adaptable to smart city emergency response networks, airport perimeter security, and regional mutual-aid firefighting consortia
Why Kitefly Tethered for Firefighting UAV Power Systems
Tethered drone power is a specialized engineering domain. The power conversion chain — from 380 V AC grid input through high-voltage tether transmission to precise low-voltage DC output matching propulsion bus requirements — involves thermal management, voltage stability under dynamic load, and cable mechanics that general-purpose power electronics suppliers are not designed to address.
Kitefly Tethered brings:
✓ 10+ years of focused tethered UAV power system development
✓ 30+ custom tethered power configurations delivered across electric, water, and heavy-lift applications
✓ One of China's earliest tethered UAV solution providers — field-proven across global markets
✓ Full power chain coverage: ground boxes (AC to HVDC), onboard modules (HVDC to drone bus voltage), and accessories
✓ Integrated accessory ecosystem: tethered lighting, firefighting modules, wash systems, relay systems, screen systems, and hangar systems
Request a Consultation or Technical Proposal
Whether you are evaluating tethered UAV firefighting systems for a municipal emergency services procurement, an airport authority deployment, or a regional wildfire response program, Kitefly Tethered's engineering team can provide technical configuration guidance, custom integration support, and formal proposal documentation.
Email: susy@tetheredsystem.com
Website: www.tetheredsystem.com
We welcome inquiries from system integrators, emergency services agencies, government procurement offices, and international distribution partners.
