Definition
FLAMEOUT PATTERN
An approach normally conducted by a single‐engine military aircraft experiencing loss or anticipating loss of engine power or control. The standard overhead approach starts at a relatively high altitude over a runway (“high key”) followed by a continuous 180 degree turn to a high, wide position (“low key”) followed by a continuous 180 degree turn final. The standard straight‐in pattern starts at a point that results in a straight‐in approach with a high rate of descent to the runway. Flameout approaches terminate in the type approach requested by the pilot (normally fullstop).
Source: FAA Pilot/Controller Glossary (verbatim from the Federal Aviation Regulations).