MANTA — deployable rigid-wing personal flight system

Live deployment

The structure deploys with the pilot.

Drag to orbit. Use the slider to scrub through the deployment sequence, or hit Play. Phase A (~0.3 s): pilot extends arms and legs from a tucked posture; the spine yoke locks the LE spars at the deployed sweep angle. Phase B (~0.1 s): CO₂ fires; telescoping wrist + ankle tip extensions snap out simultaneously. Phase D (passive): wing skin tensions across the structure.

One continuous morph-target animation (60 frames) baked by sim/build.py from the MuJoCo deployment kinematics — the slider scrubs a real animation clock, not a crossfade. The live telemetry strip is sampled from the verified flight-dynamics solution (sim/flight_dynamics.py): terminal-velocity freefall → drogue → load-limited pull-out → captured 13.7 : 1 glide at 17 m/s.

3-DOF longitudinal flight dynamics: freefall, drogue, pull-out, glide capture — Six-state longitudinal sim of the full sequence. The aero model is derived from the locked planform and reproduces every BRIEF target from first principles — terminal velocity 43.9 m/s, deploy pull-out peak 3.1 g (within the 3 g limit-load spar sizing), and a captured best-glide of 17.1 m/s at 13.7 : 1.

Headline numbers

Reproducible, traceable to source.

Wing planform is independent of mounting; the aero analyses still hold. Mass, structural, and packaging numbers updated for the corrected architecture.

Wing area

8.4 m²

Both sides; locked from BRIEF.

Span

7.4 m

Aspect ratio 6.52, taper 0.4, sweep 25°, washout 6°.

CL_α (3D, Weissinger)

4.24 /rad

≈ 0.074 /deg. Helmbold cross-checked.

Static margin (design CL)

5.4 % MAC

Top-of-BRIEF-range washout.

(L/D)ₘₐₓ

12.0

At V ≈ 16 m/s, nominal body CdA = 0.20 m².

Stowed thickness off body

87 mm

Within BRIEF target (< 150 mm). Dominated by spine yoke OD; structure runs along arms/legs, not on top of the rig.

Deployment time

≈ 0.6 s

Phase A arm spread + Phase B tip-extension + Phase D skin tension.

LE spar root OD

62 mm

Along-arm spar; slightly downsized from the 73 mm bending-sized aircraft-style root because the load path is different.

Wrist tip extension

3.30 m

3-stage telescoping CFRP; CO₂-driven.

Symmetry 3-σ |Δt|

16.3 ms

vs. BRIEF 10 ms gate — locked architecture FAILS. Active modulation closes it at 8.1 ms.

Pilot 50 mm CG shift

3.26 % MAC

≈ entire static margin. Alpha limiter mandatory.

Tests

27 / 27

Across analysis/ and fcs/. make test reproduces locally.

What the analysis surfaced

Four architecture amendments.

The analyses across deliverables #1–#6 plus the architecture rebuild produced four findings the BRIEF should be amended to reflect. Each is backed by runnable code; clicking through goes to the doc that defends it.

Finding #1

V_bg = 16 m/s, not 25 m/s

The locked planform's natural best-glide is ~16 m/s. At V = 25 m/s the wing is below its drag bucket — L/D ≈ 8.3, short of the 10:1 target.

Recommend restating BRIEF V_bg as ~16 m/s.

docs/01 →

Finding #2

Front spar must grow → 73 mm OD

BRIEF dimensions fail bending at 3 g limit by ~3× in stress. Sized at 73 mm OD root / 2.5 mm wall. Adds +1.1 kg/side.

Now relevant to the LE spar root cross-section.

docs/02 →

Finding #3

Active per-side flow modulation

The locked passive-pneumatic-sequencing architecture cannot close the 10 ms 3-σ symmetry gate. Active modulation drops 3-σ from 16.3 ms to 8.1 ms.

Replace passive sequencing with closed-loop sensing.

docs/03 →

Finding #4 — fundamental

Wingsuit-extension, not aircraft-on-back

BRIEF v1 described a separate aircraft strapped on top of a piggyback rig with pyrotechnic spar-root cutters. The actual concept is the pilot wearing a wingsuit-derivative with an arm-braced extending wing — pilot is the fuselage, structure runs along the limbs.

BRIEF v2 (current) reflects this.

BRIEF →

Deliverable #1

Aerodynamics

Pure-Python lifting-line, validated against Helmbold (rectangular AR=8: −3.4 %), feeds trim, glide polar, and the parametric wing OML. Wing planform is independent of how it integrates with the pilot — these numbers carry over from BRIEF v1 unchanged.

Glide polar L/D vs V — Glide polar across CD0 brackets. (L/D)ₘₐₓ at V ≈ 16 m/s. The BRIEF target V = 25 m/s sits below the drag bucket.

Washout sweep — Trim + washout iteration: SM, x_CG_trim, and tip stall margin vs. washout. Recommend 6° (top of BRIEF range) for 5.4 % SM.

Deliverables #2 + #3

Structures

Bending analysis uses Weissinger output as the loading shape. The cantilever load path in the new architecture is from wingtip → telescoping booms → wrist hub → along-arm LE spar → shoulder yoke → spine. Bending magnitudes carry over; the path is shorter and the moment is reacted by the spine yoke rather than a sub-frame.

Bending stress along span — Bending moment + max-fiber stress along the span at 3 g limit.

Mass budget — Component mass roll-up with the bending-sized spar. Total ≈ 16.6 kg.

Deliverables #4 + #5

Deployment + symmetry budget

State machine implements every gate and abort path; 50,000-trial Monte Carlo characterizes the symmetry budget. The CO₂ contributor dominates and busts the 10 ms 3-σ BRIEF gate alone.

Symmetry budget histogram — Distribution of |Δt_LR| across 50,000 trials. The 10 ms BRIEF gate (black) sits inside the bulk; 3-σ at 16.3 ms (red dashed). Architecture revision required.

Drogue descent profile (legacy from BRIEF v1). The new architecture deploys from spread-eagle freefall posture so a separate drogue stage isn't strictly required — but the bridle snatch (3.94 kN at 3.83 g) is still the binding harness-mount load case if used.

FCS architecture

Alpha limiter — a structural design assumption.

Per BRIEF, the alpha limiter is treated as an invariant the structure depends on. Pilot CG perturbations alone can eat the static margin; without active envelope protection, a 50 mm posture shift can destabilize the wing. The shoulder/hip rotation against the locked spar gives the pilot a wingsuit-style direct control path that maps to alpha command.

Closed-loop scenario: pilot demands α = 12° at cruise V = 20 m/s. Limiter saturates the α command at ~9° (α_stall − 2.5° margin) for 83 % of the run; anti-windup holds the inner loop integrator while saturated.

Where each deliverable stands

Program status.

Every BRIEF first-deliverable closed end-to-end with runnable analysis, real CAD, tests where logic exists, and an explicit open-issues section where the analysis stopped.

BRIEF	Deliverable	Doc	Tests	Status
#1	Aero sizing	docs/01-aero-sizing.md	5 ✓	first-cut
#2	Mass budget	docs/02-structural-budget.md	8 ✓	first-cut
#3	Spar bending	docs/02-structural-budget.md	8 ✓	first-cut
#4	Deployment sequence	docs/03-deployment-sequence.md	7 ✓	first-cut
#5	Symmetry budget	analysis/deployment/symmetry-budget.md	—	first-cut — fails 10 ms gate
#6	Ground rig spec	test/ground/spec.md	—	spec drafted
+	FCS architecture + alpha limiter	docs/04-fcs-architecture.md	7 ✓	first-cut
+	Emergency systems	docs/05-emergency-systems.md	—	first-cut
+	Test plan	docs/06-test-plan.md	—	first-cut
+	Pilot training transition	docs/07-pilot-training.md	—	syllabus drafted
+	Lateral-directional dynamics	analysis/flightdynamics/lateral.py	—	first-cut
+	Drogue dynamics	analysis/deployment/drogue_dynamics.py	—	first-cut
+	FMEA — 11 / 14 per-mode files	safety/fmea.md	—	first-cut
+	Bench characterization plan	test/bench/README.md	—	spec drafted

27 / 27 tests passing across analysis/ and fcs/.

Engineering culture

The bar.

This project kills people if done sloppily.

Every analysis is reviewable. Every assumption is cited. Every safety-critical claim has a test that backs it. No vibes-based engineering.

Would this analysis hold up if a coroner's office asked for it?

analysis/

aero · struct · deployment · flight dynamics

cad/

single parametric build (corrected architecture) · STEP + STL

safety/

FMEA · 11 per-mode write-ups · reserve compatibility

test/

bench · ground rig spec · tow · drop · manned-flight gates