AD 2012-17-08

This AD applies to Model 204B, 205A, 205A-1, 205B, and 212 helicopters, with a main rotor yoke (yoke), part number (P/N) AAI-4011-102 (all dash numbers), ASI-4011-102 (all dash numbers), or 204-011-102 (all dash numbers), installed, certificated in any category.

This AD defines the unsafe condition as a crack in a yoke. This condition could result in failure of a yoke, and subsequent loss of control of the helicopter.

This AD supersedes AD 93-05-01, Amendment 39-8507 (58 FR 13700, March 15, 1993); AD 81-19-02, Amendment 39-4208 (46 FR 45595, September 14, 1981; AD 81-19-01, Amendment 39-4207 (46 FR 45595, September 14, 1981); and AD 79-20-05, Amendments 39-3662 (45 FR 6922, January 31, 1980), 39-3626 (44 FR 70123, December 6, 1979), and 39-3572 (44 FR 55556, September 27, 1979).

This AD becomes effective February 27, 2013.

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 yoke, P/N AAI-4011-102 (all dash numbers) and ASI-4011-102 (all dash numbers), installed, within 100 hours time-in-service (TIS):

(i) Create a component history card or equivalent record for each yoke.

(ii) Determine the model for each helicopter on which the yoke has been installed from the time the yoke had zero hours TIS.

(iii) In accordance with the rate per hour categories shown in Table 1 to paragraph (f) of this AD, categorize the accumulated “Factored Hours TIS” on each yoke by determining the types of operation AND the rate per hour of external load lifts for each hour TIS accumulated on each yoke. One external load lift occurs each time the helicopter picks up an external load and drops it off. For determining the proper rate per hour category for external load operations, any external load lift in which the helicopter achieves a vertical altitude difference of greater than 200 feet indicated altitude between the pickup and drop-off point counts as two external load lifts.

(iv) By reference to Table 1 to paragraph (f) of this AD, enter the “Unfactored Hours TIS” for each category as determined by paragraph (f)(1)(iii) of this AD. Calculate the “Factored Hours TIS” by multiplying the “Unfactored Hours TIS” by the “Hours TIS Factor.” Determine the accumulated “Total Factored Hours TIS” on each yoke by adding the factored hours TIS for each type of operation and helicopter model. Tracking the Total Factored Hours TIS is only for establishing a retirement life and not for tracking inspection intervals.

(v) Record the accumulated Total Factored Hours TIS on the component history card or equivalent record for each yoke.

(vi) Continue to factor the hours TIS for each yoke by following paragraph (f)(1)(ii) through (f)(1)(iv) of this AD, and record the additional factored hours TIS on the component history card or equivalent record.

(2) For helicopters with yoke, P/N 204-011-102 (all dash numbers), installed, before further flight:

(i) For hours TIS accumulated before the effective date of this AD, calculate and record the Total Factored Hours TIS as follows:

(A) For the Model 212 helicopters, 1 hour TIS in which passenger or internal cargo was carried equals 1 factored hour TIS; 1 hour TIS where more than 4 external load lifts occurred equals 5 factored hours TIS.

(B) For the Model 204 and 205 series helicopters, 1 hour TIS equals 1 factored hour TIS.

(ii) For hours TIS accumulated after the effective date of this AD, calculate and record the factored hours TIS on the yoke in accordance with the requirements of paragraphs (f)(1)(i) thorough (f)(1)(vi) of this AD.

(3) Revise the Airworthiness Limitations section of the applicable maintenance manuals or the Instructions for Continued Airworthiness (ICAs) by establishing a new retirement life of 3,600 Total Factored Hours TIS for each yoke, P/N AAI-4011-102 (all dash numbers), ASI-4011-102 (all dash numbers), or 204-011-102 (all dash numbers), by making pen and ink changes or inserting a copy of this AD into the Airworthiness Limitations section of the maintenance manual or ICAs.

(4) Record a life limit of 3,600 Total Factored Hours TIS for each yoke, P/N AAI-4011-102 (all dash numbers), ASI-4011-102 (all dash numbers), or 204-011-102 (all dash numbers), on the component history card or equivalent record.

(5) Within 100 hours TIS or 600 hours TIS since the last magnetic particle inspection (MPI) of the yoke, whichever occurs later, and thereafter at intervals not to exceed 600 hours TIS, for any yoke installed on any Model 205B or 212 helicopter:

(i) Remove the yoke from the main rotor hub assembly (hub). Using a 5-power or higher magnifying glass, visually inspect each pillow block bushing hole, spindle radius, and center section web for any corrosion or mechanical damage.

(ii) Perform an MPI of each yoke for a crack.

(6) Within 100 hours TIS or 2,400 hours TIS since the last MPI of the yoke, whichever occurs later, and thereafter at intervals not to exceed 2,400 hours TIS, for any yoke installed on any Model 204B, 205A, or 205A-1 helicopter:

(i) Remove the yoke from the hub. Using a 5-power or higher magnifying glass, visually inspect each pillow block bushing hole, spindle radius, and center section web for any corrosion or mechanical damage.

(ii) Perform an MPI of each yoke for a crack.

(7) Before further flight, replace each yoke with an airworthy yoke if:

(i) The yoke has 3,600 or more Total Factored Hours TIS; or

(ii) The Total Factored Hours TIS for the yoke is unknown and cannot be determined; or

(iii) The yoke has any corrosion or mechanical damage that exceeds any of the maximum repair damage limits; or

(iv) The yoke has a crack.

Special flight permits may only be issued under 14 CFR 21.197 and 21.199 for the purpose of operating the helicopter to a location where the MPI requirements of paragraphs (f)(5) or (f)(6) of this AD can be performed.

(1) The Manager, Rotorcraft Certification Office, FAA, may approve AMOCs for this AD. Send your proposal to: Michael Kohner, Aviation Safety Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, TX 76137; telephone (817) 222-5170; email 7-avs-asw-170@faa.gov.

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.

Bell Alert Service Bulletin Nos. 204-92-36, 205-92-51, and 212-92-80, all dated October 23, 1992, which are not incorporated by reference, contain additional information about the subject of this AD. For service information identified in this AD, contact Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, TX 76101, telephone (817) 280-3391, fax (817) 280-6466, or at http://www.bellcustomer.com/files/. You may review a copy of this service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Joint Aircraft Service Component (JASC) Code: 6220: Main Rotor Head.