PX4 uses Calibrated Airspeed (CAS ≈ IAS × pitot scale) for all limits. While TAS increases at altitude (TAS = CAS / √σ), both stall and cruise TAS increase by the same ratio, so the safety margin stays constant.
Throttle Budget
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Required @ Takeoff Alt
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Required @ Max Alt
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Margin @ Max Alt
Safety Margins
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TKO → Stall Margin
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TKO → TRIM Gap
✈️ Recommended Parameter Changes
Only showing parameters that need adjustment for this weight/altitude combination.
✅ No Parameter Changes Required
Default parameters are appropriate for this weight and altitude.
📈 Climb Parameters by Altitude
Note: FW_THR_TRIM is set for max altitude and should not be changed in flight (causes integrator wind-up issues).
Only FW_T_CLMB_MAX and FW_T_CLMB_R_SP should be adjusted during climb.
Albatross: Wing area 0.66 m², Cl 1.02 (no flaps), 1.2 (flaps), APC 14x12 prop Model: Physics-based throttle scaling: baseline × (weight/8.1)^1.5 / √σ Validated against pai-5k.ulg (5000-10000ft climb) Motor: Standard = 52% throttle at SL baseline • High-Power = 40% throttle at SL baseline (1.29× efficiency) Climb: Efficient = max rates (less battery) • Conservative = reduced rates (more margin, ~2× climb battery) Default params: FW_TKO_AIRSPD=19, FW_AIRSPD_TRIM=20, FW_THR_TRIM=60%, FW_T_CLMB_MAX=5.5, FW_T_CLMB_R_SP=3.0, FW_TKO_PITCH_MIN=10° Known bug: TECS flare pitch constraint not enforced in v1.14 (pitch goes to 0° instead of FW_LND_FL_PMIN)