Recommendation R20010083

Recommendation issued to: Civil Aviation Safety Authority

Recommendation details
Output No: R20010083
Date issued: 05 April 2001
Safety action status:
Background: Why this Recommendation was developed

Output text

The Australian Transport Safety Bureau recommends that the Civil Aviation Safety Authority:

(i) require the fitment of approved Wire Strike Protection System kits for all helicopters engaged in low flying activities for which a kit exists; and

(ii) that only agricultural spray kits compatible with Wire Strike Protection Systems be approved for fitment to these helicopters.

This recommendation was previously issued by the Bureau of Air Safety Investigation as R19950120.

Initial response
Date issued: 01 June 2001
Response from: Civil Aviation Safety Authority
Action status: Open
Response text:

CASA has generally been of the view that regulation which requires fitment of WSPS would represent an unfair imposition on operators of helicopters capable of fitment of such devices. To regulate against helicopters incapable of fitment of WSPS would unfairly penalize the operators of such helicopters. Thus, CASA chose to leave the fitment of WSPS as voluntary, while continuing to publish the benefits of wire strike protection and the dangers inherent in low-level operations.

Despite that position, CASA is sympathetic to the ATSB recommendation and has initiated discussions with the manufacturer of WSPS (Bristol Aerospace Limited) and representatives of the Australian helicopter industry with the aims of:

1. identifying those helicopters which are both capable of fitment of WSPS and at risk from wire strike accidents;
2. improving the level of awareness of wirestrike hazards;
3. devising better methods of detection of wires; and
4. devising a strategy which will increase the level of fitment of protection systems.

While not pre-empting the results of the discussions, it is worth noting that the aviation regulatory authorities in the US and Canada have each issued Advisory Circulars highlighting the benefits of WSPS. However, neither authority has mandated their use due to the potential discriminatory nature of such legislation.

ATSB response:

On 5 April 2001, the ATSB issued recommendation R20010083 pertaining to the fitment of Wire Strike Protection Systems (WSPS) on agriculture helicopters. On 6 June 2001, we received your response to our recommendation. Included in the response was a mention of possible discussions with British Aerospace Limited (manufacturers of WSPS) in order to identify helicopters capable of fitment of WSPS. A copy of the recommendation and the CASA response is attached.

Could you please advise us of the status of the discussions with the manufacturer and their outcome including any proposed actions concerning this recommendation? If we may be of any assistance on this matter, please contact me at your convenience.

Further correspondence
Date issued: 18 April 2002
Response from: Civil Aviation Safety Authority
Response status: Closed - Partially Accepted
Response text:

I refer to your letter dated 10 March 2002 relating to Recommendation R20010083 and the fitment of Wire Strike Protection Systems (WSPS) on agricultural helicopters. Since the date of our response to this Recommendation, CASA has had extensive contact with the Bristol Aerospace Division of Magellan Aerospace Corporation, the manufacturers of WSPS. The company has confirmed the efficacy of the WSPS against cables up to 9.Smm with a breaking strength of 55kN and the availability of WSPS kits for a range of helicopters in the medium to heavy category. They have advised that their efforts to address the lighter (piston engine) helicopter market have been limited due to the lack of structure typical of these aircraft and the limitation on how much additional weight can be added. They were planning to assess the feasibility of designing equipment specifically for this market with a decision expected by end 2001/early 2002. To date, no further advice has been received from the manufacturers.

The benefits of WSPS are widely known within the helicopter industry but due to limitations in the system and its limited availability for the lighter helicopters, CASA cannot mandate its use. However CASA does take every opportunity to highlight the benefits of such systems and is monitoring the development of alternative systems for protection against the effects of wire strikes.

Last update 01 April 2011