Airworthiness Directive · Amendment 39-17733 · Main rotor control
Eurocopter France (Eurocopter) Helicopters
This AD applies to Eurocopter Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, and AS350D1 helicopters, certificated in any category, without modification (MOD) 073175 installed; with MOD 073237 installed in accordance with Eurocopter Service Bulletin No. 67.00.37, Revision 0, dated September 27, 2007, or Revision 1, dated February 6, 2008; or with one of the following serial numbers: 3972, 3973, 3982, 3987, 4003, 4023, 4046, 4050, 4086, 4120, 4122, 4132, 4143, 4152, 4172, 4194, 4259, 4314, 4324, 4378, 4392, 4447, 4452, 4477, 4489, 4490, 4501, 4523, 4546, 4560, 4589, 4594, 4599, 4632, 4659, 4666, or 4671.
We are adopting a new airworthiness directive (AD) for Eurocopter Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, and AS350D1 helicopters. This AD requires measuring the distance between the end of the main rotor collective pitch lever (collective) locking stud (locking stud) and the locking strip and repairing the locking stud if the clearance is insufficient. This AD was prompted by a report that insufficient distance between the locking stud and the locking strip may cause the collective to become inadvertently locked in the low pitch (low) position. The actions of this AD are intended to prevent the collective from becoming inadvertently locked in the low position and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) For helicopters with MOD 073237 installed, within 100 hours time-in-service (TIS):
(i) With the collective (item b) in the low position but not locked on the locking strip (item a), measure the distance between the end of the locking stud (item c) and the locking strip as indicated by dimension “J” in Figure 2 of Eurocopter Emergency Alert Service Bulletin No. 05.00.58, Revision 0, dated January 12, 2008 (EASB 05.00.58).
(ii) If the distance between the end of the locking stud and the locking strip is equal to or more than 3 millimeters (mm), no further action is required.
(iii) If the distance between the end of the locking stud and the locking strip is less than 3 mm and MOD 073175 is not installed, inspect to determine whether the grommet in the locking strip is seated against the console as shown in Figure 2 of EASB 05.00.58.
(A) If the grommet is not seated against the console, restore the original profile of the locking strip by doing the following:
(1) Clamp the locking strip in a vice with soft jaws and apply load progressively to the locking strip to restore the original profile of the locking strip.
(2) With the collective in the low position but not locked on the locking strip, measure the distance between the end of the locking stud and the locking strip as indicated by dimension “J” in Figure 2 of EASB 05.00.58.
(3) If the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm, no further action is required.
(4) If the distance between the end of the locking stud and the locking strip is less than 3 mm, adjust the length of the locking stud and re-identify the locking stud by following the Accomplishment Instructions, paragraph 2.B.2.c., of EASB 05.00.58, except you are not required to comply with paragraph 2.B.4 of EASB 05.00.58.
(B) If the grommet is seated against the console, adjust the length of the locking stud and re-identify the locking stud by following the Accomplishment Instructions, paragraph 2.B.2.c, of EASB 05.00.58, except you are not required to comply with paragraph 2.B.4 of EASB 05.00.58.
(iv) If the distance between the end of the locking stud and the locking strip is less than 3 mm and MOD 073175 is installed, adjust the length of the locking stud and re-identify the locking stud by following the Accomplishment Instructions, paragraph 2.B.2.c., of EASB 05.00.58, except you are not required to comply with paragraph 2.B.4 of EASB 05.00.58.
(v) After adjusting the length of the locking stud in accordance with paragraph 2.B.2.c of the EASB, determine whether the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm.
(A) If the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm, no further action is required.
(B) If the distance between the end of the locking stud and the locking strip is less than 3 mm, do not approve the helicopter for return to service until the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm.
(2) For helicopters without MOD 073237 installed, within 100 hours TIS:
(i) With the collective in the low position but not locked on the locking strip, measure the distance between the end of the locking stud and the locking strip as indicated by dimension “J' in Figure 2 of EASB 05.00.58.
(ii) If the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm, no further action is needed.
(iii) If the distance between the end of the locking stud and the locking strip is less than 3 mm and MOD 073175 is not installed, inspect to determine whether the grommet in the locking strip is seated against the console as shown in Figure 2 of EASB 05.00.58.
(A) If the grommet is not seated against the console, restore the original profile of the locking strip by doing the following:
(1) Clamp the locking strip in a vice with soft jaws and apply load progressively to the locking strip.
(2) With the collective in the low position but not locked on the locking strip, measure the distance between the end of the locking stud and the locking strip as indicated by dimension “J” in Figure 2 of the EASB 05.00.58.
(3) If the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm, no further action is required.
(4) If the distance between the end of the locking stud and the locking strip is less than 3 mm, do not approve the helicopter for return to service until the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm.
(B) If the grommet is seated against the console, do not approve the helicopter for return to service until the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm.
(iv) If the distance between the end of the locking stud and the locking strip is less than 3 mm and MOD 073175 is installed, do not approve the helicopter for return to service until the distance between the end of the locking stud and the locking strip is equal to or more than 3 mm.
(3) Repeat the measurement requirement in paragraphs (e)(1) or (e)(2) of this AD as applicable to your helicopter each time the collective, locking stud, or locking strip is replaced; each time the locking strip setting is readjusted; or at intervals not exceeding 660 hours TIS or 2 years, whichever occurs first.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
