Pilot/Controller Glossary 3000 feet. Runway spacing can be as close as 750 feet. (Refer to AIM.) PROCEDURAL CONTROL [ICAO]" Term used to indicate that information derived from an ATS surveillance system is not required for the provision of air traffic control service. PROCEDURAL SEPARATION [ICAO]" The separation used when providing procedural control. PROCEDURE TURN- The maneuver prescribed when it is necessary to reverse direction to establish an aircraft on the intermediate approach segment or final approach course. The outbound course, direction of turn, distance within which the turn must be completed, and minimum altitude are specified in the procedure. However, unless otherwise restricted, the point at which the turn may be commenced and the type and rate of turn are left to the discretion of the pilot. (See ICAO term PROCEDURE TURN.) intermediate approach segment of a nonprecision instrument approach. The profile descent normally terminates at the approach gate or where the glideslope or other appropriate minimum altitude is intercepted. PROGRESS REPORT- (See POSITION REPORT.) PROGRESSIVE TAXI- Precise taxi instructions given to a pilot unfamiliar with the airport or issued in stages as the aircraft proceeds along the taxi route. PROHIBITED AREA- (See SPECIAL USE AIRSPACE.) (See ICAO term PROHIBITED AREA.) PROHIBITED AREA [ICAO]- An airspace of defined dimensions, above the land areas or territorial waters of a State, within which the flight of aircraft is prohibited. PROMINENT OBSTACLE" An obstacle that meets one or more of the following conditions: a. An obstacle which stands out beyond the adjacent surface of surrounding terrain and immediately projects a noticeable hazard to aircraft in flight. b. An obstacle, not characterized as low and close in, whose height is no less than 300 feet above the departure end of takeoff runway (DER) elevation, is within 10 NM from the DER, and that penetrates that airport/heliport"s diverse departure obstacle clearance surface (OCS). c. An obstacle beyond 10 NM from an airport/ heliport that requires an obstacle departure procedure (ODP) to ensure obstacle avoidance. zyxwvut PROCEDURE TURN [ICAO]- A maneuver in which a turn is made away from a designated track followed by a turn in the opposite direction to permit the aircraft to intercept and proceed along the reciprocal of the designated track. Note 1: Procedure turns are designated "left" or "right" according to the direction of the initial turn. Note 2: Procedure turns may be designated as being made either in level flight or while descending, according to the circumstances of each individual approach procedure. PROCEDURE TURN INBOUND- That point of a procedure turn maneuver where course reversal has been completed and an aircraft is established inbound on the intermediate approach segment or final approach course. A report of "procedure turn inbound" is normally used by ATC as a position report for separation purposes. (See FINAL APPROACH COURSE.) (See PROCEDURE TURN.) (See SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE.) PROFILE DESCENT- An uninterrupted descent (except where level flight is required for speed adjustment; e.g., 250 knots at 10,000 feet MSL) from cruising altitude/level to interception of a glideslope or to a minimum altitude specified for the initial or (See OBSTACLE.) (See OBSTRUCTION.) PROPELLER (PROP) WASH (PROP BLAST)- The disturbed mass of air generated by the motion of a propeller. PROPOSED BOUNDARY CROSSING TIME- Each center has a PBCT parameter for each internal airport. Proposed internal flight plans are transmitted to the adjacent center if the flight time along the proposed route from the departure airport to the center boundary is less than or equal to the value of PBCT or if airport adaptation specifies transmission regardless of PBCT. PROPOSED DEPARTURE TIME- The time that the aircraft expects to become airborne.