Document ID: chunk:federal_register_of_legislation:F2024C01244:reg:5:p94
Version: federal_register_of_legislation:F2024C01244
Segment Type: reg
Provision Reference: reg 5 (pt 94/225)
Character Range: 555570–558218

following:

(a) an approach slope of 3º;

(b) a pilot eye-height over the threshold of 15 m;

(c) if the runway on which a T-VASIS is provided is also equipped with an ILS — the siting and elevation of the light units must be such that the T-VASIS approach slope conforms as closely as possible with the ILS glide path;

        Note   A T-VASIS eye-height over the threshold that is 1 m higher than the ILS glide path has been found to satisfy most aeroplanes.

(d) the light beams from the corresponding light units on opposite sides of the runway must have the same recognition angle, and the fly-up and fly-down light units of the  "T" must appear with uniform steps as the approach slope changes;

(e) the elevation of the beams of the wing bar light units on both sides of the runway must be the same;

(f) the elevation of the top of the beam of the fly-up light unit nearest to each wing bar, and the bottom of the beam of the fly-down light unit nearest to each wing bar, must be equal and correspond to the approach slope;

(g) the cut-off angle of the top of the beams of successive fly-up units must decrease by 5' (±½') of arc in angle of elevation at each successive unit away from the wing bar;

(h) the cut-in angle of the bottom of the beam of the fly-down light units must increase by 7' (±½') of arc in angle of elevation at each successive unit away from the wing bar;

(i) the elevation setting of the top of the red light beams of the wing bar and fly-up light units must be such that, during an approach, the pilot of an aeroplane, to whom the wing bar and 3 fly-up units are visible, would clear all objects or structures in the approach area by a safe margin, if any such light did not appear red.

       (3) Light units must be sited at least 15 m from the edge of the runway.

       (4) Light units must be sited at least 15 m from the edge of a taxiway, unless CASA approves otherwise in writing.

       (5) The standard and allowable tolerance mentioned in a row of columns 2 and 3 of Table 9.47 (5) apply to the design, installation and subsequent maintenance of the item mentioned in the same row in column 1.

     Table 9.47 (5)   T-VASIS light units — standards and tolerances for design etc.

Item                                                            Standard                       Allowable tolerance
Eye height over threshold                                       15 m1,2                        +1 m  –3 m
Approach slope3                                                 3° (1:19 nominal)
Distance of longitudinal line of light units from runway edge4  30 m                           ±3 m
Leg light unit