AD 2004-05-21 Airworthiness Directives; Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 Airplanes

Models named: DHC-8-102, -103, -106, -201, -202, -301, -311, -315. Read the applicability below — it usually turns on serial or part numbers too.

Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 airplanes; certificated in any category; serial numbers 003 and subsequent; equipped with any flap actuator having part number 734181, 734374, or 755216.

Required as indicated, unless accomplished previously. To prevent the mechanical disconnection of a flap actuator, which, if followed by failure of the flap panel's second actuator due to increased loading, could result in flap asymmetry and consequent loss of controllability of the airplane, accomplish the following: Actuator Lubrication (a) Lubricate the flap actuators at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD, in accordance with the product support manuals (PSMs) and temporary revisions (TRs) to the maintenance program manual listed in Table 1 of this AD. (1) Within 2,500 flight hours or 18 months after the most recent flap actuator lubrication, whichever occurs first. (2) Within 500 flight hours after the effective date of this AD. Table 1.—de Havilland Maintenance Program Manual TRs TR PSM Task No. MRB-143 1-8-7 2750/04 MRB 2-21 1-82-7 2750/04 MRB 3-152 1-83-7 2750/04 Initial Backlash Measurement (b) Table 2 of this AD identifies service information references for the backlash measurement. Operators may have previously used one of these references to measure the actuator backlash. Table 2.—Backlash Measurement References Reference Date Bombardier Alert Service Bulletin A8-27-95 October 31, 2001. Bombardier Alert Service Bulletin A8-27-95, Revision A April 17, 2002. Bombardier Alert Service Bulletin A8-27-98 February 20, 2003. DHC-8 Maintenance Task Card Manual, Task No. 2750/18 November 23, 2001, or later revisions issued before the effective date of this AD. Transport Canada Airworthiness Directive CF-2002-26 May 2, 2002. Measure the backlash of each actuator at the applicable time specified in paragraph (b)(1) or (b)(2) of this AD, in accordance with the Accomplishment Instructions of the applicable Hamilton Sundstrand Service Bulletin 734181-27-A5 or 734374-27-A5, both of which form part of Bombardier Alert Service Bulletin A8-27-98, dated February 20, 2003. (1) If the most recent backlash measurement has been done before the effective date of this AD in accordance with a reference listed in Table 2 of this AD: Do the applicable action specified in Table 3 of this AD. Table 3.—Intervals: Backlash Measurement Done Previously If the measurement was— Then—   Do the initial measurement within the later of: (i) ≤ 0.027 inch 3,000 flight cycles since the most recent measurement, or 90 days after the effective date of this AD. (ii) > 0.027 inch and < 0.060 inch, and the wear rate is recorded or can be calculated The applicable interval specified in Service Bulletin A8-27-98, or 90 days after the effective date of this AD. (iii) > 0.027 inch and < 0.060 inch, but the wear rate is unknown or cannot be calculated due to lack of data The applicable interval, based on a wear rate of 0.010 inch per 1,000 flight cycles, as specified in Service Bulletin A8-27-98, or 90 days after the effective date of this AD. (iv) ≥ 0.060 inch and < 0.070 inch, and the wear rate is recorded or can be calculated The applicable interval specified in Service Bulletin A8-27-98, or 30 days after the effective date of this AD. (v) ≥ 0.060 inch and < 0.070 inch, but the wear rate is unknown or cannot be calculated due to lack of data The applicable interval, based on a wear rate of 0.010 inch per 1,000 flight cycles, as specified in Service Bulletin A8-27-98, or 30 days after the effective date of this AD. (vi) < 0.050 inch, but not recorded 1,000 flight cycles since the most recent measurement, or 90 days after the effective date of this AD. (vii) ≥ 0.070 inch Replace the flap actuator with a new or overhauled part: Before further flight. (2) If no backlash measurement has been done as of the effective date of this AD in accordance with a reference listed in Table 2 of this AD: Do the next measurement at the applicable time specified in Table 4 of this AD. Table 4.—Intervals: No Prior Backlash Measurement If the actuator, since new or overhauled, has accumulated— Then do the initial measurement within— (i) ≤ 3,000 total flight cycles 3,000 total flight cycles since new or overhauled, or within 180 days after the effective date of this AD, whichever occurs later. (ii) > 3,000 total flight cycles 60 days after the effective date of this AD. Determination of Subsequent Intervals (c) After each actuator backlash measurement required by this AD, determine (calculate) the next measurement interval by the applicable time specified in Table 5 of this AD. To determine each interval, use paragraph 2.A.(4)(b) and Figure 4 of the applicable Hamilton Sundstrand Service Bulletin 734181-27-A5 or 734374-27-A5, both of which form part of Bombardier Alert Service Bulletin A8-27-98, dated February 20, 2003. Alternatively, the Bombardier spreadsheet “Dash 8 Q100/200/300 Flap Ballscrew Backlash Data, Data Recording and Charting Utility,” document number BM_DHI_RM_APP01, may be used. Table 5.—Timeframe To Determine Subsequent Intervals For any recorded backlash that was— Determine (calculate) the next interval— (1) ≥ 0.060 inch and < 0.070 inch Within 45 flight cycles after the recorded completion of backlash measurement. (2) > 0.027 inch and < 0.060 inch Within 30 days after the recorded completion of backlash measurement. (3) ≤ 0.027 inch Within 3,000 flight cycles after the recorded completion of backlash measurement. (4) Not done because the actuator was new or newly overhauled Before the accumulation of 3,000 total flight cycles on the actuator. Subsequent Repetitive Measurements (d) After the initial backlash measurement required by paragraph (b) of this AD, repeat each subsequent measurement within the applicable interval specified in paragraph (c) of this AD, in accordance with paragraph 2.A.(1) of the applicable Hamilton Sundstrand Service Bulletin 734181-27-A5 or 734374-27-A5, both of which form part of Bombardier Alert Service Bulletin A8-27-98, dated February 20, 2003. Follow-on and Corrective Actions (e) After each backlash measurement required by paragraph (b) or (d) of this AD, do the actions required by paragraph (e)(1) or (e)(2), as applicable, of this AD. Do the actions in accordance with the Accomplishment Instructions of Bombardier Alert Service Bulletin A8-27-98, dated February 20, 2003. (1) For any measured backlash of less than 0.070 inch: Repeat the measurement within the interval specified in paragraph (c) of this AD. (2) For any measured backlash of 0.070 inch or more: Replace the actuator with a new or overhauled actuator before further flight. Alternative Methods of Compliance (f) In accordance with 14 CFR 39.19, the Manager, New York Aircraft Certification Office (ACO), FAA, is authorized to approve alternative methods of compliance for this AD. Incorporation by Reference (g) Unless otherwise specified in this AD, the actions must be done in accordance with Bombardier Alert Service Bulletin A8-27-98, dated February 20, 2003; and the de Havilland temporary revisions to the applicable de Havilland Dash-8 Program Support Manuals listed in Table 6 of this AD: Table 6.—de Havilland Temporary Revisions Service information PSM Task No. Date Temporary Revision MRB-143 1-8-7 2750/04 May 18, 2001. Temporary Revision MRB 2-21 1-82-7 2750/04 May 18, 2001. Temporary Revision MRB 3-152 1-83-7 2750/04 May 18, 2001. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, FAA, 1600 Stewart Avenue, suite 410, Westbury, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Note 1: The subject of this AD is addressed in Canadian airworthiness directive CF-2002-26R1, dated October 6, 2003. Effective Date (h) This amendment becomes effective on March 25, 2004. Issued in Renton, Washington, on March 1, 2004. Ali Bahrami, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 04-5069 Filed 3-9-04; 8:45 am] BILLING CODE 4910-13-P