21. Simultaneous Converging Instrument Approaches
21.1 ATC may conduct instrument approaches simultaneously to converging runways; i.e., runways having an included angle from 15 to 100 degrees, at airports where a program has been specifically approved to do so.
21.2 The basic concept requires that dedicated, separate standard instrument approach procedures be developed for each converging runway included. Missed approach points must be at least 3 miles apart and missed approach procedures ensure that missed approach protected airspace does not overlap.
21.3 Other requirements are: radar availability, nonintersecting final approach courses, precision (ILS/MLS) approach systems on each runway, and if runways intersect, controllers must be able to apply visual separation as well as intersecting runway separation criteria. Intersecting runways also require minimums of at least 700.foot ceilings and 2 miles visibility. Straight.in approaches and landings must be made.
21.4
Whenever simultaneous converging ap-proaches are in progress, aircraft will be informed by the controller as soon as feasible after initial contact or via ATIS. Additionally, the radar controller will have direct communications capability with the tower controller where separation responsibility has not been delegated to the tower.
22.
Timed Approaches From a Holding Fix
22.1 Timed approaches may be conducted when the following conditions are met:
22.1.1 A control tower is in operation at the airport where the approaches are conducted.
22.1.2 Direct communications are maintained be-tween the pilot and the center/approach controller until the pilot is instructed to contact the tower.
22.1.3 If more than one missed approach procedure is available, none requires a course reversal.
22.1.4 If only one missed approach procedure is available, the following conditions are met.
22.1.4.1 Course reversal is not required.
22.1.4.2 Reported ceiling and visibility are equal to or greater than the highest prescribed circling minimums for the instrument approach procedure.
22.1.5 When cleared for the approach, pilots shall not execute a procedure turn. (See 14 CFR Section 91.175j.)
22.2 Although the controller will not specifically state that “timed approaches are in progress,” the assigning a time to depart the final approach fix inbound (nonprecision approach) or the outer marker or the fix used in lieu of the outer marker inbound (precision approach) is indicative that timed approach procedures are being utilized, or in lieu of holding, the controller may use radar vectors to the final approach course to establish a mileage interval between aircraft that will insure the appropriate time sequence between the final approach fix/outer marker or the fix used in lieu of the outer marker and the airport.
22.3 Each pilot in an approach sequence will be given advance notice as to the time he/she should leave the holding point on approach to the airport. When a time to leave the holding point has been received, the pilot should adjust his/her flight path to leave the fix as closely as possible to the designated time. (See FIG ENR 1.5.33.)
Federal Aviation Administration Twentieth Edition
FIG ENR 1.5.33
Timed Approaches from a Holding Fix
EXAMPLE.
At 12:03 local time, in the example shown, a pilot holding, receives instructions to leave the fix inbound at 12:07. These instructions are received just as the pilot has completed turn at the outbound end of the holding pattern and is proceeding inbound toward the fix. Arriving back over the fix, the pilot notes that the time is 12:04 and that there are 3 minutes to lose in order to leave the fix at the assigned time. Since the time remaining is more than two minutes, the pilot plans to fly a race track pattern rather than a 360 degree turn, which would use up 2 minutes. The turns at the ends of the race track pattern will consume approximately 2 minutes. Three minutes to go, minus 2 minutes required for the turns, leaves 1 minute for level flight. Since two portions of level flight will be required to get back to the fix inbound, the pilot halves the 1 minute remaining and plans to fly level for 30 seconds outbound before starting the turn back to the fix on final approach. If the winds were negligible at flight altitude, this procedure would bring the pilot inbound across the fix precisely at the specified time of 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：美国航行情报汇编 AERONAUTICAL INFORMATION PUBLICATION AIP 2(110)
