Interim Recommendation IR19970174

Interim Recommendation issued to: Civil Aviation Safety Authority

Recommendation details
Output No: IR19970174
Date issued: 06 February 1998
Safety action status: Closed



The Hughes 500 helicopter had been chartered to transfer two crewmembers and their luggage from shore to the ship "Karoo", a bulk ore carrier, at anchor near Mackay. After an uneventful flight, the pilot landed the helicopter on the port side of cargo hatch number seven. The steel cargo hatch, designated as the ship's helicopter landing site (HLS), had a smooth painted surface. The cargo hatch peaked in the centre and sloped down 0.85 degrees to both port and starboard sides. The pilot positioned the helicopter so that the tail rotor protruded over the port side edge of the hatch. In this position, the helicopter was under the influence of a crosswind from the left front quarter. The pilot reduced the engine power to idle, friction-locked the cyclic and collective controls, and locked the anti-torque pedals. He then left the cabin to supervise the disembarkation of the passengers and remove their luggage. After the passengers disembarked, the helicopter commenced to slide slowly downslope towards the edge of the cargo hatch.

The pilot ran from the right to the left side of the helicopter and attempted to unlock the anti-torque pedals and climb aboard. As he did so, the nose of the helicopter lifted when it weathercocked left into the 25-kt south-easterly wind. The helicopter, with the pilot partly on board, slid off the hatch and fell 3 m onto the main deck, landing inverted on raised piping which ran along the length of the deck. The pilot fell between the hatch and the piping and was saved from injury by two steel posts supporting the pipe system.


A factor in this accident was that the ship's HLS did not have a non-slip surface. When the weight in the helicopter was reduced following disembarkation of the passengers, the smooth hatch surface, combined with the helicopter's centre of gravity movement, resulted in the helicopter slipping on the hatch. The steel hatch had a smooth, painted surface which was not non-slip. Fortunately, no injuries resulted from this accident, but the potential for serious injury or death to personnel was clearly evident.

Factors in ship-helicopter transfers that may increase the risk of helicopter and personnel slippage include:

(a) operations are conducted in varied weather conditions;

(b) operations are conducted on ships that are under way

(c) sea spray or dew on HLS surfaces reduces the coefficient of friction of the surface;

(d) ship helicopter landing sites are subject to unpredictable movement due to the pitch and roll of the ship;

(e) some hatch covers used as a HLS may have significant camber either fore and aft or athwartships; and

(f) operations are conducted at night.


Marine regulations recommend the provision of non-slip surfaces for ship HLSs but do not mandate their provision.

Within the marine environment, the Australian Maritime Safety Authority - Marine Orders deals with safety issues relating to helicopter operations on ships operating in Australian territorial waters.


Marine Orders, part 57, Issue 2 - Helicopter Operations, makes provisions for and in relation to:

(a) The protection of the health and the security from injury of persons engaged in the loading and unloading of ships; and

(b) the safety of persons, including pilots, going on or coming from, or on board, ships,

in connection with transfer operations by helicopter.

Marine Orders part 57 states that requirements for safe arrangements for transfer operations by helicopter are regarded to have been met if arrangements, equipment, instructions and training comply with:

(a) the Australian Code of Safe Practice for Ship-Helicopter Transfers, published by AMSA; or

(b) the International Chamber of Shipping Guide to Helicopter/Ship Operations to the extent that it is not inconsistent with (a).


The Australian Code of Safe Practice for Ship-Helicopter Transfers applies to all routine transfers of personnel or goods by helicopter to or from ships while under way or at anchor. It does not apply to fixed or floating structures, or vessels employed in the offshore oil or gas industry.

Section 3 of the code deals with the HLS and states the following:

"The HLS should have a non-slip surface."

Appendix 1 states the following:

"All paint used within the limit of the clear zone of an HLS or the manoeuvring zone of an HWA [helicopter winching area] should be such as to provide a non-skid surface whether wet or dry".

These statements do not clearly affirm that it is mandatory for a ship HLS to have a non-slip surface. The word "should" indicates a recommendation for the HLS to have a non-slip surface but does not mandate it.


The International Chamber of Shipping's, "Guide to Helicopter/Ship Operations", when dealing with the provision of HLS surfaces, states the following:

"Section 4.5 Areas to be used by the helicopter landing gear or by personnel should have anti-slip surfaces even when wet".
"Section 4.2.4 The aiming circle (Touch Down Zone) should be completely covered with a matt anti-slip surface".

This publication is a guide and is not intended to be binding. Shipping companies, ships' masters and officers, helicopter operators and aircrew are all responsible for acting in accordance with relevant national regulations and company instructions.

It therefore does not appear compulsory under marine legislation for a ship HLS to have a non-slip surface.


Section 4 of the Code of Safe Practice provides an exemption from section 3 for marine pilot transfers and states the following:

"Helicopter-ship operations solely for the purpose of effecting the transfer of a marine pilot may be exempted from the provisions of [Section] 3 subject to the following:

(i) A clear area of deck exists which must be no less than twice the main rotor diameter and preferably 2D wherever possible.

(ii) The helicopter pilot brings the aircraft to a hover clear of the ship's side and then hover-taxis to the landing position or the ship's master and the helicopter pilot agree that the landing may be safely made in another manner.

(iii) Sea and weather conditions are such that the ship's master and the helicopter pilot agree that the operation may be carried out safely and in accordance with flight rules, Civil Aviation Regulations and the flight operations manual".

Correspondence received from operators conducting helicopter marine pilot transfers has described situations where the helicopter has begun to slide whilst on the deck of a vessel during embarkation and disembarkation of marine pilots. When the helicopter begins to slide, the only option available is to become airborne. This situation, particularly at night, puts at risk the lives of those disembarking or embarking as well as the helicopter crew and the ship's crew.

Marine pilot transfer operations are no different from other ship-helicopter transfer operations in that the helicopter lands on the HLS and transfers a passenger. Marine pilot transfers are usually performed with the ship under way. The danger to passengers, the helicopter crew, and the ship's crew is still present if the helicopter slips on the designated HLS.

Many ship HLSs apparently do not have a non-slip surface. A non-slip surface on a ship HLS reduces the risk of the helicopter slipping with the pitch or roll of the ship. Additionally, a non-slip surface on the ship HLS reduces the risk of injury through personnel slipping on the deck.


The Civil Aviation Regulations - Orders and Guidelines, does not deal with the surface texture of a ship HLS. The landing area, size and requirements are referred to in Civil Aviation Advisory Publication (CAAP) 92-2 (1) - Guidelines for the establishment and use of helicopter landing sites (HLS). These guidelines do not address the provision of a non-slip surface.


Operators conducting ship-helicopter transfers approve ship-based HLSs in accordance with their operations manual and guidelines laid down in CAAP 92-2 (1). No consideration is required to be given by the operator to the non-slip nature of the helicopter landing site when approving the site for their operations.


Many ship HLSs being used for ship-helicopter transfers are not equipped with non-slip surfaces. The requirement for a non-slip surface on ship HLSs is not mandated in marine legislation, although it is recommended.

Helicopter landing sites used for marine-pilot transfer operations are exempted from the recommended non-slip surface under certain conditions.

It is not a requirement for helicopter operators to consider the non-slip nature of the ship HLS surface when approving or surveying the HLS for their operations. There is no requirement in operations manuals for operators to only use a HLS with a non-slip surface.

Output text

The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority require helicopter operators involved in ship-helicopter transfers to include in their operations manual the requirement to only use helicopter landing sites with non-slip surfaces.

IR970173 also refers and was addressed to the Australian Maritime Safety Authority.

Initial response
Date issued: 12 March 1998
Response from: Civil Aviation Safety Authority
Action status: Closed - Partially Accepted
Response text:

BASI Interim Recommendation 970174 recommends that the Civil Aviation Safety Authority (CASA) require operators of helicopters involved in ship/helicopter transfers to include in their operations manuals the requirement to only use helicopter landing sites with non-slip surfaces.

The recommendation is based on a number of factors related to the accident of Hughes 369 helicopter VH-WHP on board a ship on 17 July 1997. The BASI analysis of the accident appears to lead to the assumption that the major cause of the accident was the lack of a non-slip surface on the shipboard helicopter landing site. CASA agrees that the lack of a non-slip surface was a factor in the accident but contends that the major factor was the absence of the pilot from the controls in circumstances conducive to slippage of the helicopter on the ship's deck.

Pilot at the Controls

Civil Aviation Order (CAO) 95.7 allows a pilot to leave the controls of a helicopter if that absence from the cockpit is essential to the safety of the helicopter or of the persons on, or in the vicinity of, the helicopter. It does not address the nature of the surface on which the helicopter may stand when the pilot leaves the controls, nor does it address other factors conducive to movement of the helicopter.

This deficiency was recognised by the District Flying Operations Manager, Townsville, who issued a Direction under Civil Aviation Regulation (CAR) 215(3) regarding pilots leaving the controls of a helicopter (copy attached). direction has been circulated to other Districts with a recommendation for adoption. Further, the issue of pilots leaving the controls of a helicopter while it is running will be addressed during the current regulatory review.

HLS Standards

In its Interim Recommendation, BASI has stated that CASA's Guidelines for the Establishment and Use of Helicopter Landing Sites (CAAP 91-2(1)) do not address the provision of a non-slip surface. This statement is not correct. The CAAP addresses two types of marine HLS: the ship's side HLS and the midship HLS. In both cases, the surface is addressed with the following wording:

"The LLA should be entirely within the FATO and be capable of safely accepting the static and dynamic loads of the operation as well as have a non-slip surface."

CASA does not agree that helicopter operations should be prohibited from landing at marine landing sites without non-slip surfaces when, in the opinion of the pilot, such operations can be conducted in safety. CASA considers that the guidance contained in CAAP 91-2(1) and in the Australian Code of Safe Practice for Ship - Helicopter Transfers relating to non-slip surfaces is adequate for normal operations.

Accordingly, CASA does not intend to restrict the operations of helicopters involved in marine transfers but will instead focus attention on factors to be considered before a pilot leaves the controls of a helicopter while it is running.

Attachment: Direction to Helicopter Operators

Last update 01 April 2011