Case 0 Stability Report
Preliminary FDM result: inertia, control derivatives, rate damping, and propulsion are placeholders; ADB v1.1 contains alpha-beta data only.
Database Metadata
- File:
adb_v1_1_drag_correction_0.csv - Moment/reference/CG:
(-0.000, 0.000, 0.150) m - rho:
1.090 kg/m^3, q_ref:340.625 Pa, S:1.805 m^2, b:3.950 m, c:0.457 m
Trim
- success:
True - alpha:
2.2937 deg - theta:
2.2937 deg - elevator:
-9.7286 deg - throttle:
0.1719 - residual norm:
1.415e-14
Static Stability Derivatives
- Cm_alpha:
-1.037054 /rad(stable longitudinal static sign) - Cn_beta:
+0.034377 /rad(stable directional static sign) - Cl_beta:
-0.013984 /rad(stable lateral static sign) - CL_alpha:
+5.001922 /rad - CY_beta:
-0.228001 /rad
Dynamic Modes
| Mode | Eigenvalues | wn rad/s | zeta | time constant s | Classification |
|---|---|---|---|---|---|
| phugoid | -0.0253188+0.540732j; -0.0253188-0.540732j | 0.5413 | 0.0468 | 39.4963 | stable |
| short_period | -4.45612+7.50931j; -4.45612-7.50931j | 8.7319 | 0.5103 | 0.2244 | stable |
| dutch-roll-like lateral-directional | No clearly identifiable Dutch-roll-like lateral-directional oscillatory mode was found in this linearization. | n/a | n/a | n/a | not identified |
| roll | -30.2252+0j | 30.2252 | 1.0000 | 0.0331 | stable |
| spiral | -0.00285347+0j | 0.0029 | 1.0000 | 350.4503 | stable |
Summary
- Static stability: longitudinal
stable, directionalstable, lateralstable. - Dynamic stability among identified reduced-order modes:
stable. - Weakly damped modes: phugoid.
- No clearly identifiable Dutch-roll-like lateral-directional oscillatory mode was found in this linearization. Because the aircraft uses an inverse V-tail/ruddervator layout and the current lateral reduced eigenspectrum is entirely real, treat this as a model limitation and classification ambiguity to investigate before flight-test use.
Conclusion
Case 0 is the most stable sampled case by longitudinal static and dynamic metrics, but it requires the largest elevator trim deflection. It should be treated as a forward stability bound until control authority, mass properties, and the full control model are validated.