reversal procedure

reversal procedure

A procedure designed to enable aircraft to reverse direction during initial approach segment of an instrument approach procedure. The sequence may include procedure turns or base turns (ICAO). There are three generally recognized maneuvers related to the reversal procedure, each with its own airspace characteristics:
i. A 45°/180° procedure turn. It starts at a facility or a fix and consists of a straight leg with track guidance [this may be limited by a radial or DME (distance-measuring equipment) distance]; a 45° turn; another straight leg with track guidance (this straight leg is timed; it is 1 min from the start of the turn for categories A and B aircraft and 1' 15” for categories C, D, and E aircraft); and a 180° turn in the opposite direction to intercept the inbound track. The 45°/180° procedure turn is an alternative to the 180°/260° procedure turn [described in (ii)] unless specifically excluded.
ii. A 180°/260° procedure turn. It starts at a facility or a fix and consists of a straight leg with track guidance (this leg may be timed or limited by a radial or DME distance), a 180° turn, and a 260° turn in the opposite direction to intercept inbound track. The procedure is an alternative to the 45°/180° procedure turn unless specifically excluded.
iii. A base turn. It consists of a specified outbound track and timing or DME distance from a facility followed by a turn to intercept the inbound track. The outbound track and the timing may be different for the various categories of aircraft. Where this is done, separate procedures are published.