FIG ENR 1.5.13
Final Approach Obstacle Clearance
CIRCLING APPROACH AREA RADII
Approach Category Radius (Miles)
A 1.3
B 1.5
C 1.7
D 2.3
E 4.5
11.3 Obstacle Clearance. Final approach obstacle clearance is provided from the start of the final segment to the runway or missed approach point, whichever occurs last. Side-step obstacle protection is provided by increasing the width of the final approach obstacle clearance area.
11.3.1 Circling approach protected areas are defined by the tangential connection of arcs drawn from each runway end. The arc radii distance differs by aircraft approach category (see FIG ENR 1.5.13). Because of obstacles near the airport, a portion of the circling area may be restricted by a procedural note: e.g., “Circling NA E of RWY 17.35.” Obstacle clearance
RADI (r) DEFINING SIZE OF AREAS, VARY WITH THE
is provided at the published minimums (MDA) for the pilot who makes a straight.in approach, side.steps, or circles. Once below the MDA the pilot must see and avoid obstacles. Executing the missed approach after starting to maneuver usually places the aircraft beyond the MAP. The aircraft is clear of obstacles when at or above the MDA while inside the circling area, but simply joining the missed approach ground track from the circling maneuver may not provide vertical obstacle clearance once the aircraft exits the circling area. Additional climb inside the circling area may be required before joining the missed approach track. See paragraph 27., Missed Approach, for additional considerations when starting a missed approach at other than the MAP.
Federal Aviation Administration Twentieth Edition
FIG ENR 1.5.14
Precision Obstacle Free Zone (POFZ)
11.3.2 Precision Obstacle Free Zone (POFZ). A volume of airspace above an area beginning at the runway threshold, at the threshold elevation, and centered on the extended runway centerline. The POFZ is 200 feet (60m) long and 800 feet (240m) wide. The POFZ must be clear when an aircraft on a vertically guided final approach is within 2 nautical miles of the runway threshold and the reported ceiling is below 250 feet or visibility less than 3/4 statute mile (SM) (or runway visual range below 4,000 feet). If the POFZ is not clear, the MINIMUM authorized height above touchdown (HAT) and visibility is 250 feet and 3/4SM. The POFZ is considered clear even if the wing of the aircraft holding on a taxiway waiting for runway clearance penetrates the POFZ; however, neither the fuselage nor the tail may infringe on the POFZ. The POFZ is applicable at all runway ends including displaced thresholds. (See FIG ENR 1.5.14.)
11.4 Straight.In Minimums are shown on the IAP when the final approach course is within 30 degrees of the runway alignment (15 degrees for GPS IAPs) and a normal descent can be made from the IFR altitude shown on the IAP to the runway surface. When either the normal rate of descent or the runway alignment factor of 30 degrees (15 degrees for GPS IAPs) is exceeded, a straight.in minimum is not published and a circling minimum applies. The fact that a straight.in minimum is not published does not preclude pilots from landing straight.in if they have the active runway in sight and have sufficient time to make a normal approach for landing. Under such conditions and when ATC has cleared them for landing on that runway, pilots are not expected to circle even though only circling minimums are published. If they desire to circle, they should advise ATC.
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