AD 2004-05-13 Airworthiness Directives; Bombardier Model DHC-8-401 and -402 Airplanes

Models named: DHC-8-401, -402. Read the applicability below — it usually turns on serial or part numbers too.

Model DHC-8-401 and -402 airplanes, certificated in any category, serial numbers 4003 through 4076 inclusive, and 4078 through 4081 inclusive.

Required as indicated, unless accomplished previously. To prevent cracks in the lower fuselage skin due to fatigue damage in the vicinity of the Number 2 VHF antenna, which could result in rapid decompression of the airplane, accomplish the following: Records Review (a) Within the applicable compliance time specified in Table 1 of this AD, review the airplane maintenance records to determine if the airplane has been modified or repaired in accordance with Bombardier Repair Drawing RD8/4-53-317, Issue 2, approved December 13, 2002, or earlier issue; or Bombardier Modification Summary (ModSum) Package IS4Q5300001, Revision B, approved March 17, 2003, or earlier issue. Table 1.—Compliance Time for Records Review If the total flight hours accumulated on the airplane, as of the effective date of this AD, is— Then review the records— ≤1,450 Before the accumulation of 1,900 total flight hours. >1,450 and ≤2,200 Within 300 flight hours after the effective date of this AD. >2,200 and ≤3,000 Within 150 flight hours after the effective date of this AD. >3,000 Within 50 flight hours after the effective date of this AD. Follow-on Actions: Drawing/ModSum Incorporated (b) If either Bombardier Repair Drawing RD8/4-53-317 or Bombardier ModSum IS4Q5300001, as specified in paragraph (a) of this AD, has been incorporated before the effective date of this AD: Do the terminating action required by, and at the time specified in, paragraph (d) of this AD. Follow-on Actions: Drawing/ModSum Not Incorporated (c) If neither Bombardier Repair Drawing RD8/4-53-317 nor Bombardier ModSum IS4Q5300001, as specified in paragraph (a) of this AD, has been incorporated before the effective date of this AD: Before further flight, do the actions specified in paragraphs (c)(1) and (c)(2) of this AD. (1) Perform a detailed inspection for cracking of the external surface of the fuselage skin in the area around the Number 2 VHF antenna, in accordance with Bombardier Service Bulletin 84-53-32, Revision B, dated November 24, 2003. Use a 10X magnifying glass and appropriate lighting to do the inspection. Note 1: For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.” (i) If any crack is found: Before further flight, do the actions specified in paragraphs (c)(1)(i)(A) and (c)(1)(i)(B) of this AD. (A) Repair in accordance with Bombardier Repair Drawing RD8/4-53-317, Issue 2, approved December 13, 2002. (B) Replace all 8 support cleats, part number (P/N) 85307891, at stringers 32S and 33, between stations X71.8 and X94.8, in accordance with Repair Drawing RD8/4-53-328, Issue 1, approved December 13, 2002. (ii) If no crack is found: Before further flight, do the requirements of paragraph (c)(2) of this AD. (2) Do a detailed inspection to detect discrepancies (cracks, deformation in the area of the bend radius, and broken rivets) of the support cleats, P/N 85307891, at stringers 32S and 33, between stations X71.8 and X94.8; in accordance with Bombardier Service Bulletin 84-53-32, Revision B, dated November 24, 2003. (i) If any discrepancy is found: Before further flight, remove the antenna and do a detailed inspection for cracks of the external surface of the fuselage skin underneath the antenna, in accordance with Bombardier Service Bulletin 84-53-32, Revision B, dated November 24, 2003. Use a 10X magnifying glass and appropriate lighting to do the inspection. (A) If no crack is found: Before further flight, reinforce the fuselage skin around the Number 2 VHF antenna and replace all 8 support cleats with new cleats, P/N 85307891, at stringers 32S and 33, between stations X71.8 and X94.8. Do the actions in accordance with Bombardier ModSum IS4Q5300001, Revision B, approved March 17, 2003. (B) If any crack is found: Before further flight, repair in accordance with Bombardier Repair Drawing RD8/4-53-317, Issue 2, approved December 13, 2002; and replace all 8 support cleats with new cleats, P/N 85307891, at stringers 32S and 33, between stations X71.8 and X94.8, in accordance with Bombardier Repair Drawing RD8/4-53-328, Issue 1, approved December 13, 2002. (ii) If no discrepancy is found: Repeat the inspections required by paragraph (c)(1) of this AD at the following times, as applicable: (A) If all 8 cleats have not been replaced: Repeat the inspections at intervals not to exceed 200 flight hours until accomplishment of the terminating action required by paragraph (d) of this AD. (B) If all 8 cleats have been replaced: Repeat the inspections at intervals not to exceed 500 flight hours until accomplishment of the terminating action required by paragraph (d) of this AD. Terminating Action (d) Within 4,000 flight hours after the effective date of this AD, do the actions specified in paragraphs (d)(1) and (d)(2), as applicable, of this AD. Accomplishment of the applicable requirements of this paragraph terminates the repetitive inspections required by paragraph (c) of this AD. (1) For all airplanes: Reinforce the Number 2 VHF antenna support structure in accordance with Bombardier ModSum 4-113458, Revision B-1, approved September 17, 2003. Bombardier Service Bulletin 84-53-32, Revision B, dated November 24, 2003, provides instructions for incorporating ModSum 4-113458. (2) For airplanes on which neither Bombardier Repair Drawing RD8/4-53-317 nor Bombardier ModSum IS4Q5300001 has been incorporated: Reinforce the fuselage skin around the Number 2 VHF antenna in accordance with Bombardier ModSum IS4Q5300001, Revision B, approved March 17, 2003. Alternative Methods of Compliance (e) 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 (f) Unless otherwise specified in this AD, the actions must be done in accordance with the Bombardier modification summary packages and repair drawings listed in Table 2 of this AD, as applicable. (The approval date of the repair drawings and modification summary packages appears only on the first page of these documents.) Table 2.—Applicable Service Documents Document Page number Revision level shown on the page Date shown on the page Bombardier Modification Summary Package IS4Q5300001 1-3, 6 Revision B March 17, 2003.   4, 5 Revision A December 22, 2002. Bombardier Repair Drawing RD8/4-53-317 1, 2 Issue 2 December 13, 2002.   3-5 Issue 1 December 11, 2002. Bombardier Repair Drawing RD8/4-53-328 All Issue 1 December 13, 2002. Bombardier Modification Summary Package 4-113458 All Revision B-1 September 17, 2003. Bombardier Service Bulletin 84-53-32 All Revision ‘B’ November 24, 2003. 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, 1600 Stewart Avenue, Westbury, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Note 2: The subject of this AD is addressed in Canadian airworthiness directive CF-2003-28, dated November 28, 2003. Effective Date (g) This amendment becomes effective on March 25, 2004. Issued in Renton, Washington, on February 25, 2004. Kalene C. Yanamura, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 04-4682 Filed 3-9-04; 8:45 am] BILLING CODE 4910-13-P