Definition
An informal name for the maneuver of attempting to turn back to the departure runway after a complete engine failure shortly after takeoff in a single-engine airplane. It is called 'impossible' because at low altitude and low airspeed the turn often cannot be completed safely: it requires a steep bank, loses significant altitude, and risks an aerodynamic stall and spin before the runway can be reached.
Plain English
If your only engine quits just after takeoff, turning around to land back on the runway you just left is usually a bad idea. You probably don't have enough height or speed to make it, and trying often ends in a stall and crash. The safer choice is almost always to land more or less straight ahead.
Context Anchor
Encountered in training and takeoff briefings for engine failure after takeoff in a single-engine airplane.
Derivation
Called 'impossible' not because the turn can never physically be made, but because pilots historically attempted it, failed, and crashed often enough that the name stuck as a warning. The label is meant to discourage the attempt rather than describe a strict aerodynamic impossibility.
Why Pilots Care
Attempting the turn below roughly 800–1,000 feet AGL is a leading cause of fatal stall-spin accidents after takeoff; landing straight ahead is usually the safer option.
Grounding Statement
Picture the engine quitting just after liftoff: the airplane is close to the ground, slowing down, and the pilot has only seconds to choose where to land.
Intuition Check
Do not read “impossible” as “always impossible.” In this context, it means “usually unsafe unless there is enough height, planning, and practice.”
Example Sentence 1
During his takeoff briefing, the instructor reminded the student that below 700 feet AGL they would land straight ahead rather than attempt the impossible turn.
Example Sentence 2
Instructors stress that the impossible turn should never be attempted without both adequate altitude and recent practice.