Joined: 11 Dec 2005
|Posted: Wed Apr 12, 2006 5:30 am Post subject: Obstacle clearance in the approach phase
|Q. Regarding the approach phase:
1) what is the obstacle clearance requirement in the initial and intermediate approach segments
2) where does the intermediate segment start from
3) and what is the real significance of the intermediate segment
1) Initial approach segment provides at least 1000 feet obstacle clearance in the primary area (984 feet to be precise). During the intermediate approach the obstacle clearance requirement reduces from 1000 feet to 500 feet in the primary area (984 & 492 feet to be precise), reducing laterally to zero at the outer edge of the secondary area.
2) When a final approach fix is specified then the intermediate approach segment begins when the aircraft is on the inbound track of the procedure turn, base turn or final inbound leg of the race track procedure. When FAF is not specified, the inbound track is the final approach segment.
3) From what I know, intermediate segment is the right time to adjust aircraft speed and configuration for the final approach.
Primary Area: A defined area symmetrically disposed about the nominal flight track in which full obstacle clearance is provided.
Secondary Area: A defined area on each side of the primary area located along the nominal flight track in which decreasing obstacle clearance is provided.