(4)
Where 180 or 250 KIAS is required, publish a speed restriction. Example: “Do not exceed (180/250) KIAS,” or “Do not exceed (180/250) KIAS until CHUCK WP.”
8. AREA.
a. Initial Climb Area. See appendix 1, figure 1.
(1)
All departures must proceed along runway alignment during the initial climb to a specified WP past DER. Locate the first WP after DER on extended runway centerline at a sufficient distance from DER to allow the aircraft to climb to at least 400 feet above airport elevation. The minimum distance allowable for fly-by WP’s is 2 NM or the DTA distance measured from the beginning of the fix displacement tolerance area. A shorter distance of 1 NM is allowed for a fly-over WP published with a climb gradient. See appendix 1, figure 1. Also, where the 400 feet above airport elevation requirement is not achieved for the first WP publish a climb gradient. See paragraph 12a.
(2)
Initial Segment Width. See appendix 1, figure 2. From a point 500 feet each side of runway centerline:
(a) Splay the area at 7.5°
, angular with the course line, until it reaches the width of the primary area, or the departure terminates, whichever occurs first. Where a turn occurs prior to the initial segment completing 2 NM primary width, refer to instructions in paragraph 9a(8).
(b) From the same point, splay a line at 15°
, angular with the course line, until it reaches a distance of 1 mile from the primary area boundary. This defines the secondary area width.
b. Departure Route Segments.
(1)
Length. Segment length is measured between plotted positions of the WP’s. Except for the initial climb area, the length of a segment shall be sufficient to encompass all turn anticipation and outside turn expansion requirements. The minimum segment length:
(a) In the case of two successive fly-by turning waypoints, is the DTA and the ATRK fix displacement tolerance of the first waypoint plus DTA including the ATRK fix displacement tolerance of the second waypoint. See figure a below.
Step 4. Compute the DTA of the second turn waypoint plus fix displacement tolerance: 2.7 NM
Step 5. Compute the minimum segment length by adding the two dimensions derived in steps 1 through 4:
Minimum Length of Segment = 2.7 + 2.7 = 5.4 NM
(b) In the case of two successive fly-over waypoints, use the following formula:
X= r2 + θ -1.732 cos θ
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Where: X = distance from the first TWP to the ATRK fix displacement tolerance of the second TWP. r = the radius of turn, table 2.
θ = angle of turn
Determine the fix displacement tolerance from table 1 and add this dimension to X to obtain the total distance between the TWP’s.
Example steps of computation:
Given:
Aircraft speed: 250 KIAS
Altitude: Below 10,000’ MSL
First turn angle: 45°
Second turn angle: (not applicable)
First TWP within 30 NM of ARP
Step 1.
X = 4.2 [2 + sin 45 -1.732 cos 45] = 6.2 NM
Step 2. Determine the fix displacement tolerance from table 1.
Step 3. Add the two dimensions calculated in steps 1 and 2:
X + fix displacement tolerance = 6.2 + 1 = 7.2 NM.
Figure c.
Example steps of computation:
Given:
Aircraft Speed: 250 KIAS
First Turn: 50°
Altitude: More than 10,000’ MSL
Segment more than 30 NM from ARP.
Step 1. Determine the turning radius of first turn from table 2:5.5 NM
Step 2. Determine DTA of first turn:
DTA = Turn Radius × Tangent (50°÷2) = 2.6 NM
Step 3. Add the DTA derived in step 2 plus the fix displacement tolerances, (en route), of
both WP’s:
Minimum Length of Segment = 2.6 + 2.0 + 2.0= 6.6 NM
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