Airworthiness Directive · Amendment 39-14695 · Eurocopter Canada Limited Model BO 105 LS A-3 Helicopters
Eurocopter Canada Limited Model BO 105 LS A-3 Helicopters
Model BO 105 LS A-3 helicopters certificated in any category.
This amendment adopts a new airworthiness directive (AD) for Eurocopter Canada Limited (Eurocopter) Model BO 105 LS A-3 helicopters that requires replacing certain fixed bolts and nuts, re-identifying certain main rotor nuts, and revising the Airworthiness Limitations-- Time Change Items (TCI) list to reflect the new life limits and new part numbers. This amendment is prompted by a re-evaluation of certain fatigue-critical parts, which resulted in establishing new life limits for certain like-numbered parts and re-identifying a certain existing part with a different part number, or in some cases, replacing them with new parts. The actions specified by this AD are intended to prevent fatigue failure of the fixed bolts and nuts, and subsequent loss of control of the helicopter.
To prevent fatigue failure of a fixed bolt and main rotor nut, and subsequent loss of control of the helicopter, accomplish the following:
(a) Within 30 days:
(1) Modify the Airworthiness Limitation section, Time Change Items (TCI) list, or table of life-limited components, with their revised life limits by adding part number (P/N) 105-142241.01 and by changing P/N LN 9038 K08018 to P/N 105-101021.17, as shown in the following table.
| Part name | P/N | Life limit |
|---|---|---|
| Fixed Bolt (Bolt) | 105-101021.17 (Formerly P/N LN 9038-K08018) | 6,000 hours time-in-service (TIS). |
| Main Rotor Nut (Nut) | 105-142241.01 | 122,850 flights or 18,900 hours TIS, whichever occurs first. |
(2) Create a historical or equivalent record for each of the parts listed in the preceding table.
(3) Review the aircraft records and determine the TIS and landings on each nut, P/N 105-142241.01. If the number of flights (i.e., landings) is unknown, the initial life limit is 18,900 hours TIS. Thereafter, record the number of flights for use when determining the retirement life.
(b) Before further flight, replace any nut that has less than 150 hours TIS remaining before reaching its life limit. Unless accomplished previously, prior to replacing a nut, re-identify the nut in accordance with paragraph (c)(2) of this AD.
(c) Within 150 hours TIS:
(1) Replace the 4 bolts, P/N LN 9038 K08018, with bolts, P/N 105-101021.17, as shown in Figure 1 of Eurocopter Alert Service Bulletin No. ASB BO 105 LS 10-11, dated May 11, 2005 (ASB).
(2) For those nuts with 150 or more hours TIS remaining on their life, remove and re-identify those nuts, P/N 105-142241.01, by adding the serial number of the main rotor head, followed by a dash and a consecutive number, in accordance with the procedures stated in Figure 2 of the ASB.
(d) Before further flight, remove any life-limited part on which the life limit has been equaled or exceeded.
(e) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Contact the Manager, Regulations and Policy Group, Rotorcraft Directorate, FAA, ATTN: Sharon Miles, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Guidance Group, Fort Worth, Texas 76193-0111, telephone (817) 222-5122, fax (817) 222-5961, for information about previously approved alternative methods of compliance.
