Multi-Engine V-Speeds Explained: Vmc, Vyse, Vsse, and Vxse

Walk up to a multi-engine airplane and you’ll see two colored lines on the airspeed indicator you didn’t have in a single: a red line and a blue line. Knowing what those speeds mean — and the two unmarked ones behind them — is foundational to flying a twin safely, and it’s a guaranteed topic on your checkride. Here’s how a Designated Pilot Examiner wants to hear them explained.

Vmc — the red line

Vmc is the minimum control speed with the critical engine inoperative — the slowest speed at which you can maintain directional control under the certification conditions. It’s marked in red because below it, with an engine out and the other at full power, you may not be able to keep the airplane pointed where you want it. Vmc isn’t about stalling; it’s about control.

Vyse — the blue line

Vyse is the best single-engine rate of climb — the speed that gives you the most altitude gain per minute on one engine. After an engine failure, blue line is the number you fly. It’s the speed that buys you the most performance when you have the least to spare, which is exactly why examiners care that you fly it precisely rather than approximately.

Vsse — safe single-engine speed

Vsse is the minimum speed the manufacturer recommends for intentionally shutting down or restricting an engine — for example, during training. It exists to keep you comfortably above Vmc when you deliberately introduce an engine failure, so a demonstration never becomes a real loss of control. If you teach or take multi-engine training, this is the speed that keeps the exercise safe.

Vxse — best single-engine angle

Vxse is the best single-engine angle of climb — the most altitude gained per unit of distance on one engine. You’d reach for it when you need to clear an obstacle after an engine failure, trading some rate of climb for a steeper angle. It comes up less often than blue line, but knowing the difference between Vyse and Vxse shows real understanding.

Putting them together

The mental model an examiner is listening for: Vmc keeps you in control, Vyse gets you the most climb, Vxse gets you over the obstacle, and Vsse keeps training safe. Memorizing the acronyms is easy; being able to say when you’d use each is what passes the oral.

Free download: The Multi-Engine Checkride Readiness Checklist lists every speed and concept an examiner will expect you to teach — free. For the full breakdown in short video lessons, see the Multi-Engine Training Series, built by a DPE with a 30-day money-back guarantee.