89-05-04 R1 BOEING: Amendment 39-6148 as revised by Amendment 39-6484. Docket No. 89-NM-107-AD. \n\n\tApplicability: Model 747 series airplanes, listed in Boeing Service Bulletin 747-57A2229, Revision 7, dated October 13, 1988, certificated in any category, that have reworked or interim production flap tracks (part numbers identified in the service bulletin). \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo preclude additional flap track failures, accomplish the following: \n\n\tA.\tAccomplish either paragraph A.1. or A.2., below according to the compliance schedule indicated. \n\n\t\t1.\tAccomplish A.1.a. through A.1.c., below: \n\n\t\t\ta.\tWithin five landings after March 8, 1989, (the effective date of Amendment 39-6148), revise the limitations section of the FAA-approved Airplane Flight Manual (AFM) by adding the following instructions. This may be accomplished by inserting a copy of this AD into the AFM: \n\n\t\t\t\t"Landing Flaps \n\n\t\t\t\tMaximum landing flaps shall not exceed 25 degrees, unless deemed necessary for safe operation by the pilot. The pilot shall document each use of 30 degree flaps in the airplane log book." \n\n\t\t\tb.\tWithin 15 landings after March 8, 1989, and thereafter at intervals not to exceed 15 landings, until paragraph B.2., below, is accomplished on the affected tracks, perform a close visual inspection of both sides of each flap track for cracks emanating from the first four fail-safe bar fastener holes of flap track numbers 1, 3, 6, and 8 (Borescope inspections, conducted in accordance with Boeing Alert Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989, or through the access hole in the forward end fairing, are acceptable). \n\n\t\t\tc.\tWithin 10 landings after any use of 30 degree flaps, conduct the inspection specified in paragraph A.1.b., above. \n\n\t\t2.\tWithin 15 landings after March 8, 1989, and thereafter at intervals not to exceed 5 landings, until paragraph B.2., below, is accomplished on the affected track, perform a close visual inspection of both sides of each flap track for cracks emanating from the first four fail-safe bar fastener holes on each side of flap track numbers 1, 3, 6, and 8 (eight holes per track). (Borescope inspections, conducted in accordance with Boeing Alert Service Bulletin 747- 57A2229, Revision 9, dated November 2, 1989, or through the access hole in the forward end fairing, are acceptable.) \n\n\tNOTE: Although 30 degree flaps are not prohibited in complying with paragraph A.2., it is recommended that 25 degree flaps be used whenever possible. \n\n\tB.\tWithin 75 landings after March 8, 1989, (the effective date of Amendment 39-6148), remove the bolts from the first four fail-safe bar fastener holes on each side of the track (eight per track) of flap track numbers 1 through 8 (except tracks 4 and 5 with a spliced-in end fitting) and accomplish B.1. or B.2., below: \n\n\t\t1.\tInspect fastener holes for cracks, in accordance with the eddy current procedures identified in Boeing Alert Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989. If no cracks are found, prior to further flight, apply an organic corrosion inhibitor (LPS-3 or equivalent) to the fastener hole and reinstall serviceable fasteners using corrosion inhibiting grease. Repeat at intervals not to exceed 75 landings. \n\n\t\t2.\tVerify that fastener holes are: \n\n\t\t\ta.\tCorrosion-free, by using magnifying borescope inspection procedures described in the enclosure to Boeing Letter B-221T-89-247, dated January 24, 1989, entitled "Borescope Inspection of Flap Track Holes, " and \n\n\t\t\tb.\tCrack-free, by using eddy current inspection procedures described in Boeing Alert Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989. \n\n\tRepeat these inspections at intervals not to exceed 1,500 landings. Bolts are to be reinstalled as noted in paragraph B.1., above. Verification that fastener holes are crack-free and corrosion-free constitutes terminating action for the requirements of paragraph A., above, for that track. Any track, which on subsequent inspection is found to have developed corrosion in a fastener hole, must be inspected in accordance with paragraphs A. and B.1., above, until the condition is corrected. \n\n\tC.\tFor tracks inspected in accordance with paragraph B.2., above, within 300 landings after tracks have been found to be crack-free and corrosion-free, and at intervals thereafter not to exceed 300 landings, perform an ultrasonic and close detailed visual inspection of both sides of the forward end of each track for cracks, with the fairing removed, in accordance with Boeing Alert Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989. \n\n\tD.\tWithin 150 landings after March 8, 1989 (the effective date of Amendment 39-6148), unless accomplished within the last 150 landings, and thereafter at intervals not to exceed 300 landings, remove the fairing from the forward end of flap tracks number 4 and 5 with spliced-in end fitting, and perform an ultrasonic and close detailed visual inspection of both sides of the forward end of each track for cracks, in accordance with the inspection procedures described in Boeing Alert Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989. \n\n\tE.\tWithin the next 50 landings after August 15, 1988 (the effective date of AD 88-16-03, Amendment 39- 5985), unless accomplished within the past 950 landings, and thereafter at intervals not to exceed 1,000 landings, visually inspect numbers 1 through 8 flap track webs for cracks extending from all fastener holes not inspected in accordance with the requirements of paragraphs A., B., C., or D., above, or paragraph L., below. These visual inspections must be accomplished in accordance with the procedures described in Boeing Service Bulletin 747-57-2146, Revision 4, dated August 25, 1988. \n\n\tF.\tCracked tracks must be replaced or reworked prior to further flight in accordance with Boeing Alert Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989, or Boeing Service Bulletin 747-57-2146, Revision 4, dated August 25, 1988. \n\n\tG.\tTracks which have had any of the first four fail-safe bar fastener holes reworked in accordance with Boeing Alert Service Bulletin 747-57A2229, Revision 7, dated October 13, 1988, or in accordance with any other procedure approved by the FAA, are subject to the requirements of paragraph A. and B.1., above, until compliance with paragraph B.2., above, is established. \n\n\tH.\tCarriage of fifth engine is not permitted unless a close visual inspection, described in paragraphs A.1.b. or A.2., above is conducted prior to the flight. \n\n\tI.\tReplacement of any flap track with a flap track approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, constitutes terminating action for the inspection requirements of this AD for that flap track. \n\n\tJ.\tAn alternate means of compliance or adjustment of the compliance time, whichprovides an acceptable level of safety, may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office. \n\n\tK.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. \n\n\tL.\tWithin 300 landings after the effective date of this amendment, and thereafter at intervals not to exceed 300 landings, remove the fairing from the forward end of flap track numbers 1 through 8 (except tracks 4 and 5 with a spliced-in end fitting) and visually inspect the flap track webs for cracks extending from the fifth through the tenth most- forward fail-safe bar fastener holes on each side of the track. These visual inspections must be accomplished inaccordance with the procedures described in Boeing Service Bulletin 747-57-2146, Revision 4, dated August 25, 1988. \n\n\tM.\tWithin the next 9 months after the effective date of this amendment accomplish the following on the first four fail-safe bar fastener holes on each side of the track (eight per track) of flap track numbers 1 through 8 (except tracks 4 and 5 with a spliced-in end fitting): \n\n\t\t1.\tModify the fastener holes in accordance with Boeing Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989. \n\n\t\t2.\tVerify that modified fastener holes are crack-free and corrosion-free in accordance with paragraph B.2., above. (NOTE: Modification of the fastener holes does not terminate the repetitive inspection requirements of paragraph B.2.) \n\n\tN.\tFor airplanes on which the first four flap track fail-safe bar fastener holes have been verified to be corrosion-free in accordance with paragraph B.2. of this AD, within 6 months after the effective date of this amendment, and until reworked and interim production flap tracks are replaced with more durable later design flap tracks in accordance with Boeing Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989, revise the Limitations Section of the Airplane Flight Manual (AFM) by adding the following instructions: \n\n\t\t"Landing Flaps \n\n\t\tMaximum landing flaps shall not exceed 25 degrees, unless deemed necessary for safe operation by the pilot." \n\n\tNOTE: In complying with paragraphs A. through D. and paragraph N. only, above, Boeing Service Bulletin 747- 57A2229, Revision 7, dated October 13, 1988, or Revision 8, dated January 31, 1989, may be used in lieu of Boeing Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989. \n\n\tIn complying with paragraph M., above, Boeing Service Bulletin 747-57A2229, Revision 8, dated January 31, 1989, may be used in lieu of Boeing Service Bulletin 747-57A2229, Revision 9, dated November 2, 1989. In complying with paragraphs E., F., and L., above, Boeing Service Bulletin 747-57-2146, Revision 3, dated May 9, 1986, may be used in lieu of Boeing Service Bulletin 747-57-2146, Revision 4, dated August 25,1988. \n\n\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis AD revises AD 89-05-04, Amendment 39-6148. \n\n\tThis amendment (39-6484, AD 89-05-04 R1) becomes effective on February 23, 1990.