Product profile
Fi4
Fi4 is ACSL confined-space inspection drone. It uses a carbon-fiber core, foam bumper, stable flight controls and IP55 protection for narrow pipes and hars...
Facts
- Company
- ACSL
- Product type
- uav
- Status
- active
- Website
- https://product.acsl.co.jp/en/product/post-435/
About Fi4
Fi4 combines a rigid carbon-fibre core with a replaceable foam bumper that protects the aircraft during contact and provides flotation. Its forward-biased propeller arrangement lets the drone move through a narrow pipe without pitching sharply, reducing the control difficulty and risk of striking the surrounding surface.
A waterproof gimballed camera captures cracks and defects, while orthogonal imaging supports subsequent measurement. The 2.4-kilogram aircraft is IP55 rated, flies for approximately four minutes and reaches three metres per second. A dedicated smart-controller application displays the pipe environment in real time. ACSL developed Fi4 with NJS for sewer and closed-space inspection.
Summary
Type: Inspection drone
Core: Confined flight
Function: Find defects
Audience: Inspectors
Specifications
- aircraft_weight
- 2.4 kg including survey camera and battery
- applications
- Sewer and duct survey, pipe navigation, GPS-denied inspection, confined-space survey
- bumper
- replaceable foam; flotation
- controller
- Smart controller with dedicated app, real-time pipe condition display
- core_material
- Carbon fiber
- dimensions
- 610 mm length, 290 mm width, 145 mm body height, 220 mm camera-side height
- flight_time_minutes
- About 4 minutes maximum flight time min
- ingress_protection
- IP55
- propeller_layout
- forward-biased layout for pipe-like spaces
- speed_range
- 3 m/s maximum flight speed m/s
Research, Articles and recent verified events
- ACSL and Draganfly sign Canadian distribution and integration agreement for SOTEN — 2026-05-07
- ACSL receives two Japan orders for small aerial photography drones worth ¥420M — 2026-04-07
- ACSL renews Japan's first Class 1 Type Certificate for PF2-CAT3 — 2026-03-24
- ACSL receives ¥1B Japan order for small aerial photography drones — 2026-03-23
- ACSL PF2-CAT3 supports Level 4 medical delivery demonstration in Nagasaki — 2026-02-19
- ACSL and Japan Post demonstrate PF4 dual-drone operation for logistics and patrol missions — 2026-02-16
- ACSL starts Canadian sales business and signs SOTEN distributor agreement with Jam Industries — 2025-12-04
- Fukuoka Prefecture uses ACSL drones in disaster-damage survey training — 2025-06-05