Vxse, Vyse, and Vsse: Multi-Engine Speeds
- wifiCFI
- Jan 1
- 4 min read
Multi-engine training has a funny moment: you spend weeks becoming a smooth, competent two-engine pilot… and then the instructor says, “Cool. Now let’s pretend one of them died.”
That’s where V-speeds go from trivia to survival tools.
Three in particular show up in every multi syllabus and every oral:
Vsse — safe single-engine speed
Vxse — best angle of climb single-engine (a.k.a. “best angle of not-descending”)
Vyse — best rate of climb single-engine (blue line)
Let’s unpack what they mean, why they’re different, and how to use them without turning it into a memorization contest.
Study this full length lesson (video, podcast, flashcards, and quiz) here: Full Length Lesson >
The One Rule That Makes All Three Speeds Make Sense
When you lose an engine, you lose more than half your performance. You lose:
thrust (obviously)
propeller drag (if it’s windmilling)
rudder authority margin (because asymmetry)
and a chunk of lift/drag efficiency (because you’re carrying the dead engine and often adding drag to control yaw)
So these speeds aren’t “go fast because fast is good.” They’re about balancing:
enough airspeed for control
enough airspeed for climb performance
without adding unnecessary drag
Vsse: Safe Single-Engine Speed (The “Don’t Be Cute” Speed)
Vsse is a practical speed, not a performance “best.” Think of it as:
“A speed where you have a comfortable control margin with one engine inoperative while you sort things out.”
It’s typically used for:
initial engine-out response after liftoff
training maneuvers where you want an added buffer above minimum control speed
situations where you’re configured or distracted and want stability more than peak performance
How to think about it in real life
Vsse is the speed you use when:
you don’t yet have the airplane cleaned up
you’re still identifying/confirming
you want to reduce the chance of getting slow, yawed, and behind the airplane
It’s a “stability and controllability” choice.
Common student mistake: treating Vsse like Vyse. It’s not. Vsse is often lower than Vyse and is chosen for safety margin, not best climb.
Vyse: Best Rate of Climb Single-Engine (Blue Line)
Vyse is the star of engine-out performance. It’s the “blue line” on most multi airspeed indicators for a reason.
If you can climb on one engine, you’ll typically climb best at Vyse.
“Vyse gives you the greatest altitude gain per unit of time.”
That’s what you want when:
you’re trying to stop descending and start climbing
you need the most climb performance possible
you’re clearing terrain in the broader sense (not necessarily the steepest angle, but the best sustained climb)
Practical use: Your target once the airplane is stabilized
A good mental flow:
control / directional stability
identify / verify / feather
clean up drag
set Vyse and hold it
Common student mistake: chasing blue line before the airplane is configured. If you’re still gear-down/flaps-out and the dead prop is windmilling, aiming for Vyse is like flooring the gas with the parking brake on.
Vxse: Best Angle of Climb Single-Engine (The “Obstacle” Speed)
Vxse is about:
“Most altitude gained per unit of horizontal distance.”
If you need to clear something close-in—like trees off the departure end—Vxse is theoretically the speed that gives you the steepest single-engine climb angle.
The reality check
In many light twins, single-engine climb performance is… modest. Sometimes it’s near zero, and sometimes it’s negative depending on density altitude, weight, and how fast you cleaned up.
So Vxse is important to understand, but it’s not magic. It’s simply the best of whatever the airplane can do that day.
Common student mistake: thinking Vxse is always the right choice after an engine failure on takeoff. In practice, you often stabilize at Vsse, clean up and secure, then go to Vyse. Vxse may come into play if you’re truly obstacle-limited and already stable and configured.
How These Speeds Relate to Each Other (and Why They’re Not Always in the Same Order)
In many training twins you’ll often see something like:
Vsse: lower “safe” speed
Vxse: higher than Vsse
Vyse: highest (blue line)
But that is not a law of physics. It’s an aircraft-specific set of numbers based on testing and manufacturer guidance.
Why Vyse is usually higher than Vxse
Best angle speeds tend to be slower
Best rate speeds tend to be faster
Same concept as in single-engine flying—just with less excess power available and a lot more yaw/drag to manage.
The “Correct Use” Scenario: Engine Failure After Takeoff (Pilot Mindset)
Here’s the pilot-focused, no-drama sequence most multi instructors want to see (always follow your POH and training standards):
Maintain control
Pitch for a safe speed (often Vsse initially)
Keep the ball centered / appropriate rudder input
Configuration check: reduce drag
Gear up (if applicable), flaps to the proper setting
Identify → verify → feather (as trained)
Set Vyse (blue line) for best sustained climb
Continue the checklist / brief the plan
Where Vxse fits:
If you’re obstacle-limited and already stable and configured, Vxse can be a short-term target
But you generally don’t want to be slow and asymmetric and busy unless you truly must be
The Trap Door: Confusing Vsse With Vmc (and Why That’s Dangerous)
Pilots sometimes mash together:
Vmc (minimum control speed)
Vsse (safe single-engine speed)
They’re related, but not interchangeable.
Vmc is the edge of directional control under specific conditions (often the “worst case” test setup).
Vsse is a recommended operational speed to keep you away from that edge.
If you fly close to Vmc while distracted, you can get into a situation where you run out of rudder before you run out of airspeed—and that’s when multi-engine airplanes get unforgiving.
Training Tip: Stop Memorizing; Start Visualizing
If you want these speeds to stick, picture three goals:
Vsse: “I need stability while I fix the problem.”
Vyse: “I need maximum climb performance over time.”
Vxse: “I need the steepest climb over the ground.”
Bottom line
Multi-engine flying isn’t about knowing three numbers. It’s about knowing what problem you’re solving:
Vsse buys you control margin and breathing room.
Vyse is the best chance you have at a positive climb on one engine.
Vxse is about clearing something close-in—when the airplane and the day actually allow it.
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