Recommendation

I refer to your letter dated 18 September 2001 notifying CASA of
Air Safety Recommendations which relate to Occurrence No. 200103038
on the serious incident involving a Sikorsky S76C helicopter,
VH-EXX, which occurred 45km east of Longford Helicopter Landing
Site, Vic on 11 July 2001. Please accept my apologies for the delay
in my reply.



In response to the Recommendations R20010192 and R20010196, CASA
advises the following:



Recommendation R20010196



The Australian Transport Safety Bureau recommends that the Civil
Aviation Safety Authority take appropriate action to ensure the
continued airworthiness of Australian registered aircraft fitted
with Turbomeca Arriel engines incorporating modification TU204.
CASA has been advised that the engine manufacturer, Turbomeca,
cancelled the incorporation of Modification TU 204 in 1998. The
DGAC has advised of action to be taken to address engines in
service incorporating TU204. CASA notes that the DGAC, in advice to
the ATSB dated 31 December 2001, advises the DGAC will be issuing
an Airworthiness Directive to require the mandatory removal of
turbine blades incorporating modification TU 204. The Directive is
to be limited to single engine helicopters. CASA will review the
DGAC Airworthiness Directive on its receipt and advise the ATSB of
the results of that review. CASA looks forward to receiving a final
briefing on the conclusions of the ATSB investigation of Occurrence
No. 200103038. Thank you for referring this matter to the attention
of the Authority.

Thank you for providing a copy of Air Safety Occurrence Report
200103038 on the serious incident involving Sikorsky S76C which
occurred 83km east of Longford Helicopter Landing Site, Victoria on
11 July 2001.



The Occurrence Report incorporates Recommendation 20010196:



The Australian Transport Safety Bureau recommends that the
Australian Civil Aviation Authority take appropriate action to
ensure the continued airworthiness of Australian registered
aircraft fitted with Turbomeca Arriel engines incorporating
modification TU204.



CASA's response included that it would review the Direction
Generale de I'Aviation Civile Airworthiness Directive on its
receipt and advise ATSB on the results of that review. The review
has been completed and CASA has issued Airworthiness Directive
AD/ARRIEL/16 with effect from 8 August 2002.



I believe the Authority's action in respect of this Report has been
finalised.