COASTAL TRANSIT
(a)General
(1)Helicopters operating overwater in performance class 3 have to have certain equipment fitted. This equipment varies with the distance from land that the helicopter is expected to operate. The aim of this GM is to discuss that distance, bring into focus what fit is required and to clarify the operator's responsibility, when a decision is made to conduct coastal transit operations.
(2)In the case of operations north of 45N or south of 45S, the coastal corridor facility may or may not be available in a particular state, as it is related to the State definition of open sea area as described in the definition of hostile environment.
(3)Where the term ‘coastal transit’ is used, it means the conduct of operations overwater within the coastal corridor in conditions where there is reasonable expectation that:
(i)the flight can be conducted safely in the conditions prevailing;
(ii)following an engine failure, a safe forced landing and successful evacuation can be achieved; and
(iii)survival of the crew and passengers can be assured until rescue is effected.
(4)Coastal corridor is a variable distance from the coastline to a maximum distance corresponding to three minutes’ flying at normal cruising speed.
(b)Establishing the width of the coastal corridor
(1)The maximum distance from land of coastal transit, is defined as the boundary of a corridor that extends from the land, to a maximum distance of up to 3 minutes at normal cruising speed (approximately 5 - 6 NM). Land in this context includes sustainable ice (see (i) to (iii) below) and, where the coastal region includes islands, the surrounding waters may be included in the corridor and aggregated with the coast and each other. Coastal transit need not be applied to inland waterways, estuary crossing or river transit.
(i)In some areas, the formation of ice is such that it can be possible to land, or force land, without hazard to the helicopter or occupants. Unless the competent authority considers that operating to, or over, such ice fields is unacceptable, the operator may regard that the definition of the ‘land’ extends to these areas.
(ii)The interpretation of the following rules may be conditional on (i) above: CAT.OP.MPA.137(a)(2); CAT.IDE.H.290; CAT.IDE.H.295; CAT.IDE.H.300; and CAT.IDE.H.320.
(iii)In view of the fact that such featureless and flat white surfaces could present a hazard and could lead to white-out conditions, the definition of land does not extend to flights over ice fields in the following rules: CAT.IDE.H.125(d); and CAT.IDE.H.145.
(2)The width of the corridor is variable from not safe to conduct operations in the conditions prevailing, to the maximum of 3 minutes wide. A number of factors will, on the day, indicate if it can be used — and how wide it can be. These factors will include, but not be restricted to, the following:
(i)meteorological conditions prevailing in the corridor;
(ii)instrument fit of the aircraft;
(iii)certification of the aircraft — particularly with regard to floats;
(iv)sea state;
(v)temperature of the water;
(vi)time to rescue; and
(vii)survival equipment carried.
(3)These can be broadly divided into three functional groups:
(i)those that meet the provisions for safe flying;
(ii)those that meet the provisions for a safe forced landing and evacuation; and
(iii)those that meet the provisions for survival following a forced landing and successful evacuation.
(c)Provision for safe flying
(1)It is generally recognised that when flying out of sight of land in certain meteorological conditions, such as those occurring in high pressure weather patterns (goldfish bowl — no horizon, light winds and low visibility), the absence of a basic panel (and training) can lead to disorientation. In addition, lack of depth perception in these conditions demands the use of a radio altimeter with an audio voice warning as an added safety benefit — particularly when autorotation to the surface of the water may be required.
(2)In these conditions, the helicopter, without the required instruments and radio altimeter, should be confined to a corridor in which the pilot can maintain reference using the visual cues on the land.
(d)Provision for a safe forced landing and evacuation
(1)Weather and sea state both affect the outcome of an autorotation following an engine failure. It is recognised that the measurement of sea state is problematical and when assessing such conditions, good judgement has to be exercised by the operator and the commander.
(2)Where floats have been certificated only for emergency use (and not for ditching), operations should be limited to those sea states that meet the provisions for such use — where a safe evacuation is possible. Ditching certification requires compliance with a comprehensive number of requirements relating to rotorcraft water entry, flotation and trim, occupant egress and occupant survival. Emergency flotation systems, generally fitted to smaller CS-27 rotorcraft, are approved against a broad specification that the equipment should perform its intended function and not hazard the rotorcraft or its occupants. In practice, the most significant difference between ditching and emergency flotation systems is substantiation of the water entry phase. Ditching rules call for water entry procedures and techniques to be established and promulgated in the AFM. The fuselage/flotation equipment should thereafter be shown to be able to withstand loads under defined water entry conditions which relate to these procedures. For emergency flotation equipment, there is no specification to define the water entry technique and no specific conditions defined for the structural substantiation.
(e)Provisions for survival
(1)Survival of crew members and passengers, following a successful autorotation and evacuation, is dependent on the clothing worn, the equipment carried and worn, the temperature of the sea and the sea state. Search and rescue (SAR) response/capability consistent with the anticipated exposure should be available before the conditions in the corridor can be considered non-hostile.
(2)Coastal transit can be conducted (including north of 45N and south of 45S — when the definition of open sea areas allows) providing the provisions of (c) and (d) are met, and the conditions for a non-hostile coastal corridor are satisfied.