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.
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.
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.
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.
