Multiengine Operations
The asymmetric problem
A twin-engine airplane's second engine is a trade: more power, but the loss of one engine creates yaw, roll, and a large performance penalty. Learn the V-speeds as definitions, not letters. Vmc is the minimum controllable airspeed with the critical engine failed and the other at maximum power - a red radial line and the true lower limit of directional control. Vsse is the minimum speed for intentional single-engine operation. Vyse is single-engine best rate of climb (often a blue radial). Single-engine service ceiling is the altitude at which the aircraft can climb 50 fpm on one engine.
Which engine is critical?
The critical engine, when failed, produces the most adverse yaw. On a conventional twin with both propellers turning clockwise from the cockpit, the left engine is critical because its P-factor, accelerated slipstream, and spiraling slipstream act farther from the fuselage.
What raises Vmc
Vmc increases (gets worse) with: aft center of gravity, high power on the operating engine, the aircraft out of ground effect, gear and flaps up, and up to 5° of bank toward the operating engine. Vmc decreases with forward CG and with higher gross weight. A question that gives you aft CG is usually asking for "higher Vmc."
Handling an engine failure
The sequence is maintain control (reduce bank, pitch for Vyse or blue line), identify (dead foot, dead engine), verify (throttle back on the suspected engine), feather and secure, and never below Vmc. Reduce drag before adding power: gear and flaps up, cowl flaps as required. Fly a single-engine approach at Vyse or higher and expect a go-around decision to be made early - with one engine, there is no margin for a late go-around.
Trap
Vmc is a calibrated airspeed; at high altitude the same indicated Vmc corresponds to a higher true airspeed, which is why the margin over stall narrows in the flight levels.