PA.IX.F.K2FAA-S-ACS-6C · Nov 2023Knowledge
VMC (red line), VYSE (blue line), and safe single-engine speed (VSSE).
VMC (red line), VYSE (blue line), and safe single-engine speed (VSSE).
Bottom line
VMC is the calibrated airspeed at which, following the sudden critical loss of thrust, it is possible to maintain control of the airplane, and it is typically marked with a red radial line on most airspeed indicators. VYSE is the best rate of climb speed with one engine inoperative, marked with a blue radial line on most airspeed indicators. VSSE is the safe, intentional one-engine-inoperative speed, originally known as safe single-engine speed. No intentional engine failure in flight should ever be performed below VSSE.
Key numbers
| Number | What it means |
|---|---|
| red radial line on most airspeed indicators | VMC red line |
| blue radial line on most airspeed indicators | VYSE blue line |
| turn stopped within 20 degrees of original heading | VMC heading |
| no more than 5 degrees angle of bank | VMC bank |
| approximately two to three degrees of bank toward the operating engine at Vyse | Zero sideslip bank |
FAA references
- AFH ch. 13 (pp. 13-1–13-2) — FAA-H-8083-3C
- FAA-P-8740-66, Flying Light Twins Safely — FAA-P-8740-66
- PHAK ch. 9 (p. 9-3) — FAA-H-8083-25C (2023)
- AFH ch. 13 (p. 13-37) — FAA-H-8083-3C
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