EP450 · Aircraft Data
Part B carve-out for the EP450: single open prop + TVC vanes, ductless, removable fixed wing. Read alongside Part A (family procedures).
Maturity. The EP450 PCU is built, weighed and hover-tested
[V]. The winged aircraft has not yet flown — its winged performance below is real-time SITL[S]and engineering estimate[E], calibrated to bench data. Do not quote as demonstrated; figures will be re-issued to[V]after flight test.
Reference (demonstrator) configuration
Section titled “Reference (demonstrator) configuration”1.40 m wing + 12S1P 231 Wh (2× Ovonic 6S 5200 LiPo) + 750 g payload, all-up weight held < 5 kg.
| Spec | Value | Src |
|---|---|---|
| Configuration | Single-motor TVC tail-sitter, removable wing, ductless | [V] |
| All-up weight | 5.01 kg (demonstrator); ceiling 6.0 kg | [E]/[V] |
| Payload | 0.75 kg reference; 0–1.5 kg envelope | [E] |
| Wingspan | 1.40 m (removable); area 0.196 m², AR 10, NACA 4412 | [V] |
| Cruise speed | ~22 m/s (79 km/h) design best-range | [S] |
| Stall speed (Vs) | 18.3 m/s (66 km/h) at 5.01 kg | [E] |
| Dash speed | ~200 km/h (prop pitch-capped) — untested | [E] |
| One-way range | ~38 km at 750 g on 231 Wh (up to 60 km on the largest pack) | [S]/[E] |
| Endurance | ~26 min (231 Wh, best-range) | [E] |
| Hover thrust | 9.75 kgf burst / 7.5 kgf continuous | [V] |
| Hover T/W (demonstrator) | 1.50 | [E] |
| Hover wind limit | 11.7 m/s (yaw-authority-limited) | [E] |
| Transport | 450 mm tube, wing stowed alongside | [V] |
Limitations (EP450)
Section titled “Limitations (EP450)”Hard limits — read with the family Limitations
chapter. The winged aircraft is pre-flight-test: several limits are [S]/[E] and will be
re-issued after flight test.
| Limitation | Value | Src |
|---|---|---|
| GTOW ceiling | 6.0 kg (hover T/W 1.25 on 7.5 kgf continuous) — do not exceed | [V]-derived |
| Demonstrator all-up weight | 5.01 kg (reference configuration) | [E] |
| Payload envelope | 0–1.5 kg (0.75 kg reference) | [E] |
| Cruise speed | ~22 m/s (79 km/h · 43 kt) design best-range — open-loop on throttle | [S] |
| Maximum airspeed | not established — dash capability (~200 km/h) is uncleared [E]; do not command above cruise band pending flight test |
— |
| Stall speed (Vs) | 18.3 m/s (66 km/h · 36 kt) at 5.01 kg | [E] |
| Bank limit | 60° (min sustained turn radius ≈ 39 m) | [S] |
| Hover / launch wind limit | 11.7 m/s (42 km/h · 23 kt), yaw-authority-limited | [E] |
| Transition altitude | forward transition at ≥ 30 m AGL | [S] |
| Transitions per sortie | one forward transition (heading recovery after back-transition not yet guaranteed) | [S] |
| Battery | RFD-approved 12S configurations only (range table below) | — |
| Launch/recovery pad | ≥ 2 m × 2 m clear (family standard) | — |
| Weather / light | Day VLOS · no precipitation · no icing band (family rules) | — |
| Temperature | Operational −10…+45 °C; battery in use +10…+40 °C (family bands) | [E] |
| Maximum continuous hover time | ~18 min (to be confirmed at flight test) | [E] |
Anatomy
Section titled “Anatomy”- Fuselage: Ø120 mm constant section, tangent-ogive nose; ~0.76 m body nose-to-tail.
- Wing (removable): 1.40 m span, root 168 / tip 112 mm, area 0.196 m², AR 10, NACA 4412, +2° incidence. A shorter 700 mm wing (same planform, clipped) exists for speed/wind-limited work.
- Propeller: APC 15×12 two-blade, Ø 381 mm (open — mind the arc).
- Tail / landing gear: four swept X-tail fins double as the landing gear.
- TVC: twelve slipstream vanes provide pitch/roll/yaw control.
- Motor / ESC: Hacker A60-7XS V4 · APD 120F3X (production; a Flycolor 80 A dev unit flies the prototype) · 12S bus.
- CG: 444 mm aft of the nose tip (16 % static margin); hold ±5 mm, re-measure at build weight.
Weight & balance [E] (weighed where marked [V])
Section titled “Weight & balance [E] (weighed where marked [V])”CG limit: 444 mm aft of the nose tip (16 % static margin); hold ±5 mm; re-measure at build weight and after any payload or battery change. As on the EP250, the CG station and its fore/aft limits are marked on the skin (printed CG symbol with forward/aft limit arrows) — balance on a knife-edge; the balance point must fall between the arrow tips.
| Item | Mass |
|---|---|
| PCU (motor+ESC+prop+servos+vanes+fins+rear fuselage) | 1.728 kg [V] |
| Avionics module | 0.156 kg [V] |
| Forward fuselage (nose, bays, bulkheads, wiring) | 0.390 kg |
| Wing (1.40 m) | 0.426 kg |
| Empty | 2.700 kg |
| Battery (2× 6S 5200) | ~1.56 kg |
| Payload (reference) | 0.750 kg |
| All-up weight | ~5.01 kg |
GTOW ceiling 6.0 kg = hover T/W 1.25 on 7.5 kgf continuous. Do not exceed.
Range across battery options (750 g payload, best-range cruise)
Section titled “Range across battery options (750 g payload, best-range cruise)”| Pack (12S) | Wh | AUW | Cruise | One-way range | Endurance | Note |
|---|---|---|---|---|---|---|
| 2× 6S 5200 (12S1P) | 231 | 5.01 kg | 22 m/s | ~38 km [S] / 37 [E] |
~26 min | demonstrator (< 5 kg) |
| 2× 6S 4000 (12S1P) | 178 | 4.67 kg | 23 m/s | ~30 km [E] |
~22 min | lightest |
| 4× 6S 4000 (12S2P) | 355 | 5.89 kg | 26 m/s | ~50 km [E] |
~33 min | > 5 kg, under 6 kg ceiling |
| 4× 6S 5200 (12S2P) | 462 | 6.57 kg | 27 m/s | ~60 km [E] |
~37 min | ⚠️ over the 6 kg ceiling |
Ranges are one-way, still-air, reusable (soft VTOL landing with reserve); headwind reduces them.
Manoeuvre & transition performance [S]/[E]
Section titled “Manoeuvre & transition performance [S]/[E]”Turns (5.01 kg, bank limit 60°): minimum sustained radius ≈ 39 m at the 25.8 m/s corner (2 g); at cruise, ~47 m radius / ~27 °/s at 1.45 g; at 35 m/s dash, ~72 m. Plan orbits around ~50 m.
Forward transition: near-flat — climbs only ~2 m, hands off at the ~22 m/s design speed; transition at ≥ 30 m AGL. Take off aligned with the outbound bearing.
Back transition: expect a ~15–17 m balloon at ~3.4 g as cruise speed converts to altitude; allocate ~20 m of vertical clearance above the hover point.
EP450-specific operating notes
Section titled “EP450-specific operating notes”- 🟡 No airspeed sensor. Cruise speed is open-loop on throttle and drifts with wind/weight/ density — watch ground speed and keep margin above the 18.3 m/s stall. Fit a pitot before relying on a precise cruise speed or automatic stall protection.
- Weak hover yaw. The single motor cannot slew a large heading quickly in hover — take off already pointed where you want to fly.
- Manage landing energy. The vertical descent is expensive; begin recovery with a real reserve.
- Fly one forward transition per sortie (heading recovery after back-transition is not yet guaranteed).
Compliance
Section titled “Compliance”NDAA at production spec (Hacker DE motor, APD AU ESC, APC US prop); dev-only FC/ESC/PM are swapped for delivery. Payload/logistics platform — no interceptor/warhead variant; DEC/DSGL discipline applies.
Status & flight-test gates
Section titled “Status & flight-test gates”[V]: PCU weighed 1.728 kg; bench 9.75 kgf; PCU hover (1 Jul 2026, no wings). [S]: winged
demonstrator flies the full max-range mission in real-time SITL — 38.5 km one-way at 22 m/s, soft
(0.42 m/s) landing. Before first winged flight: strapped-aircraft yaw bench at build weight ·
weigh the as-built wing + pack (confirm < 5 kg) · cruise-power calibration flight · add EP450 to the ReOC.