Applicability:
Model AS 350 B, B1, B2, BA, BB and D helicopters, equipped with
upper and lower stabiliser fins pre-MOD 073288.
Model AS350 B3 helicopters, equipped with upper and lower
stabiliser fins pre-MOD 073288, or, upper and lower stabiliser fins
post-MOD 073288, with the upper fin pre-MOD 073148.
Requirement:
For Model AS 350 B, B1, B2, BA, BB and D
helicopters:
1. Replace the upper fin and lower fin attachment screws in
accordance with paragraph 2.B. of Eurocopter AS 350 Alert Service
Bulletin (ASB) No. 55.00.12. As of 30 June 2006 it is prohibited to
install screws part number 22201BC060016L or part number
22201BV060016L on upper and lower fins. For Model AS 350 B3
helicopters.
Helicopters equipped with upper and lower fins pre-MOD 073288, with
the upper fin pre-MOD 073148:
2. Replace the upper and lower fin attachment screws in accordance
with paragraph 2.B.2. of ASB No. 55.00.13.
2.a. Check the tightening torque of the upper fin attachment screws
and check there is no cracking and no loose rivet in the upper fin
reinforcement splice, in accordance with paragraph 2.B.3. of ASB
No. 55.00.13.
(i) If a crack is detected in the reinforcing splice, replace the
fin, scrap the two attachment screws and replace them before
installing a new fin, in accordance with paragraph 2.B.3.a.1. of
ASB No. 55.00.13.
(ii) If the tightening torque of one or both of the attachment
screws is less than 80% of the minimum torque value and/or if there
is a loose rivet, check that there is no cracking in the upper fin
spar, in accordance with paragraph 2.B.3.a.2. of ASB
55.00.13,
- If there is a crack in the spar, replace the upper fin, scrap the
two attachment screws and replace them before installing a new fin
in accordance with paragraph 2.B.3.a.2. of the ASB,
- If there is a loose rivet, replace the loose rivet(s), scrap the
two attachment screws and replace them in accordance with paragraph
2.B.3.a.2. of the ASB,
- If there is no cracking and no loose rivet, scrap the two
attachment screws and replace them in accordance with paragraph
2.B.3.a.2. of the ASB,
(iii) If the tightening torque of the two attachment screws is
equal to or more than 80% of the minimum torque value and if there
is no cracking and no loose rivet, scrap the two attachment screws
and replace them in accordance with paragraph 2.B.3.a.3. of the
ASB. Helicopters equipped with upper and lower fins pre-MOD 073288,
with the upper fin post-MOD 073148.
3. Replace the upper and lower fin attachment screws in accordance
with paragraph 2.B.2. of the ASB. Helicopters equipped with upper
and lower fins post-MOD 073288 with the upper fin pre-MOD
073148.
4. Check the tightening torque of the upper fin attachment screws
and check that there is no crack and no loose rivet in the upper
fin reinforcement splice, in accordance with paragraph 2.B.3. of
ASB No. 55.00.13.
a. If a crack is detected in the reinforcement splice, replace the
fin, scrap the two attachment screws and replace them before
installing a new fin, in accordance with paragraph 2.B.3.a.1,
b. If the tightening torque of one or both of the attachment screws
is less than 80% of the minimum torque value and/or there is a
loose rivet, check there is no crack in the upper fin spar, in
accordance with paragraph 2.B.3.a.2,
- If a crack is detected in the spar, replace the upper fin, scrap
the two attachment screws and replace them before installing a new
fin, in accordance with paragraph 2.B.3.a.2,
- If there is a loose rivet, replace the loose rivet(s), scrap the
two attachment screws and replace them in accordance with paragraph
2.B.3.a.2,
- If there is no cracking and no loose rivet, scrap the two
attachment screws and replace them in accordance with paragraph
2.B.3.a.2, c. If the tightening torque of the two attachment screws
is equal to or more than 80% of the minimum torque value, and if
there is no cracking and no loose rivet, scrap the two attachment
screws and replace them in accordance with paragraph 2.B.3.a.3.
Note: EASA AD 2006-0060-E refers.
Compliance:
1. At the next “T” inspection after 15 March 2006 or
before 30 June 2006, whichever occurs first.
2. Within 110 flight hours after 15 March 2006.
2.a. At intervals not to exceed 110 flight hours.
3. At the next 500 hour inspection after 15 March 2006 or before 31
March 2006, whichever occurs first.
4. Within 110 flight hours after 15 March 2006, and thereafter at
intervals not to exceed 110 flight hours.
This Airworthiness Directive becomes effective on 15 March
2006.
Background: The European Aviation Safety Agency
received two reports of cracks in the spar of the upper fin on AS
355 N helicopters. Undetected crack growth could lead to failure of
the spar and consequent loss of the fin. For the AS 350 B3
helicopters, compliance with this Directive cancels the
requirements of DGAC AD F-2005-010 (AD/ECUREUIL/107), planned to be
replaced, in the very short term by an EASA AD, without
modification to its technical content.