Manual of Standards Part 173—Standards Applicable to Instrument Flight Procedure Design
(b) VAA-H;(b) VAA-H;
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8.8.1.1 A certified designer may design the instrument approach and landing procedures mentioned in this section for helicopter point-in-space (PinS) operations, provided the procedures are only for operators approved by CASA.
8.8.1.2 The instrument approach and landing procedures in Part IV of PANS-OPS for helicopter PinS RNP APCH approach procedures may be used as an alternative to the instrument approach and landing procedures mentioned in this section.
8.8.2 Administration
8.8.2.1 Helicopter procedures under this section are:
(a) classified as specialised helicopter operations; and
(b) must be annotated, in the header and footer, with the following words in upper case bold font: FOR USE BY CASA-APPROVED OPERATORS ONLY.
The use of the specialised helicopter procedures is limited to CASA‑approved operators only.
Note The CASA Area Office forwards to the Manager, CNS/ATM, copies of the relevant parts of each prospective operator’s operations manual. The Manager provides operators with an approval for each TIFP, in accordance with Part 173 of CASR 1998 and this MOS. CNS/ATM also maintains a register of operators authorised to use the procedures, and holds the relevant part of the operators’ operations manuals.
8.8.3 Procedure Overview
8.8.3.1 All helicopter procedures designed under this section are to be designed in consultation with the local operator. Helicopter procedures are dependent upon visual segment procedures developed by the operator in consultation with the procedure designer. Operational procedures must include key visual features, hazards, routes to be flown and action to be taken in the event that meteorological conditions deteriorate below specified requirements and any other conditions relating to the procedure.
8.8.3.2 The operating procedures are to be included in the Operations Manual of an operator approved to use the procedure.
8.8.4 Visual Approach Area—Helicopter
8.8.4.1 Helicopter procedures will normally be designed with a Visual Approach Area - Helicopter (VAA-H).
8.8.4.2 Procedures that do not provide a VAA-H are to be noted accordingly on the approach chart.
8.8.4.3 The VAA-H criteria are based on the establishment of key visual lead-in features to the HLS. In this respect, each procedure will be unique and requires an operational specification to be included in an operator’s operations manual.
8.8.4.4 The procedure designer must liaise with operators to define key lead-in features.
8.8.4.5 During validation, particular attention has to be considered for local operating procedures and key lead-in features.
Section (b) VAA-H; - Manual of Standards Part 173—Standards Applicable to Instrument Flight Procedure Design - (b) VAA-H; | Zoe
8.8.4.6 This area is located between the MAPT and the HLS within which obstacle clearance at MDA is assured.
8.8.4.7 Operations within a VAA-H are visual flight manoeuvres. Once visual contact is established during the instrument approach, the helicopter is positioned within the VAA-H and manoeuvred utilising key lead-in points at altitudes not below the MDA until the HLS is sighted. (See AIP).
8.8.4.8 The missed approach criteria detailed in PANS-OPS are modified to take account of the VAA-H.
8.8.4.9 The centre of the HLS must be surveyed to an accuracy of 1/100th of a second of arc.
8.8.5 VAA-H Dimensions
8.8.5.1 Area. The VAA-H starts at the commencement of the missed approach segment with a width equal to the width of the final segment primary area at that point. Its boundaries join at a tangent to a circle of 926 m radius centred on the HLS (see Figure 8-28).
Visual approach area — helicopter
Figure 8-28: Visual approach area — helicopter
8.8.5.2 Length. The nominal length of the VAA-H is 3 km. The actual length is determined by the distance from the MAWP to the centre of the HLS. In any event, it should be such as to allow visual reference to be maintained with the HLS or key lead-in points.
8.8.6 Obstacle Clearance
8.8.6.1 A minimum obstacle clearance (MOC) of 90 m (295 ft) shall apply throughout the VAA-H. The principle of secondary areas does not apply.
8.8.7 Missed Approach
8.8.7.1 In addition to the standard missed approach analysis, a missed approach analysis for the VAA-H is also required. When considering these missed approaches, the obstacle distance (doH) is measured via the shortest distance from the boundary of the VAA-H or missed approach turn initiation area boundary (see Figure 8-29).
Turning missed approach
Figure 8-29: Turning missed approach
8.8.7.2 Straight Missed Approach. The VAA-H sits within the protected area of the straight missed approach segment. Accordingly, no adjustments are required for the straight missed approach splay (see Figure 8-30).
Figure 8-30: Straight missed approach
Figure 8-30: Straight missed approach
8.8.7.3 Turning Missed Approach. Depending on the turn angle, the VAA-H can extend beyond the protected area of the turning missed approach segment (see Figure 8-29) In this event, the turning missed approach area is extended on the outside of the turn by drawing a straight line from the outside edge of the splay at the nominal MAHWP or MATWP at a tangent to the 926 m radius arc around the HLS. The MOC in this extended area is 40 m (130 ft).
8.8.8 Calculation of MDA
8.8.8.1 The MDA for the procedure is the highest calculated OCA of the following the: