Document ID: chunk:federal_register_of_legislation:F2022C00813:reg:300:p20
Version: federal_register_of_legislation:F2022C00813
Segment Type: reg
Provision Reference: reg 300 (pt 20/27)
Character Range: 123396–126237

is 2 NM and is fully contained by the procedure area.

       The development of the 2.4 NM area semi-width is based on an area length of 8.4 NM. This distance allows a helicopter transit time of 9.4 minutes to the OIP at a G/S of 44 kt for the crew to assess the obstacle situation and determine the MDA/H.

       The area semi-width is derived from the distance that would be travelled by a notional surface ship moving at 15 kt towards the MAPt at right angles to the procedure axis, during the time it takes a helicopter to travel 8.4 NM to the OIP.

8.6.7.3              In the missed approach, the procedure is a semi-circle of 4 NM radius centred on the ATP and extending down-track from the ATP, as shown in Figure 8-22.

8.6.8                   Flight crew operating tolerance

8.6.8.1              Radar tracking tolerance for a TIFP must not exceed 0.75 NM.

8.6.8.2              The radar tracking tolerance mentioned in paragraph 8.6.8.1 must be included in the operations manual of an operator using the TIFP.

8.6.9                   Obstacle clearance

8.6.9.1              Obstacle clearance before the VF. The following applies:

(a)         minimum obstacle clearance over obstacles and low terrain must be 1 000 ft; and

(b)         if the elevation of an obstacle or low terrain, including small structures on the obstacle or terrain, exceeds 500 ft AMSL, then the elevation must be added to the initial approach altitude.

           Note   Vertical errors associated with mapping or a database must be included in the 500 ft obstacle clearance.

8.6.9.2              Obstacle clearance after the VF. Minimum obstacle clearance must be applied to the sea surface, and include a minimum wave height of 50 ft, in accordance with PANS-OPS such that the final segment minimum obstacle clearance and the MDA are, respectively, as follows:

(a)         300 ft and 350 ft, using pressure altimetry (BAROALT); and

(b)         200 ft and 250 ft using radar altimetry (RADALT).

8.6.9.3              For observed obstacles (other than ATP) either in the procedure area or radially within 4 NM of the ATP in the missed approach, additional obstacle clearance allowance must be applied in the TIFP, being the greater of:

(a)         200 ft; or

(b)         the known obstacle height.

8.6.9.4              If a wave height is forecast, or observed, to exceed 50 ft, the MDA/H must be increased by the amount by which the forecast wave height, or the observed radio altimeter fluctuations, exceed 50 ft.

8.6.10              Values

 In determining minima:

(a)         minimum altitudes must be rounded up to the nearest 10 ft; and

(b)         visibilities must be rounded up to the nearest half kilometre.

8.6.11              Allowance for tidal rise and fall

 A TIFP must account for a tidal rise and fall of up to 50 ft by