Document ID: chunk:federal_register_of_legislation:F2024C01244:reg:5:p96
Version: federal_register_of_legislation:F2024C01244
Segment Type: reg
Provision Reference: reg 5 (pt 96/225)
Character Range: 560811–563333

taxiway or physical obstruction makes it impossible to locate the units on the left-hand side of the runway, the PAPI can be placed on the right-hand side of the runway.

       (4) As shown in Figure 9.50 (5), a PAPI must be installed and adjusted so that a pilot making an approach:

(a) when on or close to the approach slope — sees the 2 units nearest the runway as red and the 2 units farthest from the runway as white; and

(b) when above the approach slope — sees the one unit nearest the runway as red and the 3 units farthest from the runway as white; and

(c) when further above the approach slope — sees all the units as white; and

(d) when below the approach slope — sees the 3 units nearest the runway as red and the unit farthest from the runway as white; and

(e) when further below the approach slope — sees all the units as red.

       (5) A double-sided PAPI must:

(a) consist of 8 light units symmetrically disposed about the runway centreline in the form of 2 wing bars of 4 light units each; and

(b) be such that the indications seen by the pilot are symmetrical, so that when on or close to the approach slope, the 2 light units nearest the runway, in both wing bars, show red.

       (6) Each PAPI light unit must:

(a) be suitable for both day and night operations; and

(b) have colour transition from red to white in the vertical plane such that it appears to an observer, at a distance of not less than 300 m, to occur within a vertical angle of not more than 3 minutes of arc; and

(c) at full intensity, have a red light "y" coordinate not exceeding 0.320; and

(d) have a light intensity distribution as shown in Figure 9.48 (6); and

(e) have a suitable light intensity control which allows adjustments to be made:

 (i) to meet the prevailing conditions; and

 (ii) to avoid dazzling pilots during approach and landing; and

(f) be capable of adjustment in elevation so that the lower limit of the white part of the beam may be fixed at any desired angle of elevation between 1°30' and at least 4°30' above the horizontal; and

(g) be so designed and constructed that contamination from, for example, deposits of snow, ice, condensation, dirt or animal faeces, on optically-transmitting or reflecting surfaces:

 (i) interferes to the least possible extent with the light signals; and

 (ii) does not affect the elevation of the transition sector; and

 (iii) does not affect the contrast between the red and white signals.

     Figure 9.48 (6)   Light intensity distribution of PAPI