65-23-01 VICKERS: Amdt. 39-145 Part 39 Federal Register September 30, 1965. Applies to Viscount Models 744, 745D, and 810 Series Airplanes.
Compliance required as indicated.
As a result of reported cracks in the inner and outer wing spar attachment joint lugs, inspections were made and a number of airplanes were found to have cracks in the spar boom joint lugs. These cracks may occur on any one of the fingers of the joint lugs and appear to originate in the taper holes and then generally progress in a direction parallel to the joint lug. Accordingly, the following must be accomplished:
(a) Unless already accomplished as required by AD 61-23-05, within the next 20 hours' time in service after the effective date of this AD, inspect for cracks using ultrasonic methods, or FAA-approved equivalent, all the outer wing to inner wing spar boom attachment joint lugs, top and bottom, right and left, and the inner wing to center section spar boom attachment joint lugs, top and bottom, right and left, in the region of the taper bolt holes.
(1) If cracks are found in any of the lower spar boom joints, replace with new spar booms before further flight.
(2) If no cracks are found in any of the lower spar boom joints, airplanes having cracks in the top spar boom joints, within the limits specified in (a)(2)(i) may be continued in service provided the inspection required by (a) is repeated on the affected top spar boom joints at intervals specified in (b)(4).
(i) One crack is permitted in any of the top four joints, i.e., a total of four cracks per airplane. Permissible cracks are those extending completely between two adjacent holes in one lug only; or extending between the bolt hole nearest the end of one lug and the end of that lug; or between the bolt hole nearest the boom body and a line one inch from this hole toward the body of the boom, in one lug only. A number of small cracks confined within any one of these areas may be considered as one single crack for the purpose of this limitation.
(3) If cracks beyond the limits specified in (a)(2)(i) are found in any of the top spar boom joints, replacement with a new top spar boom is required before further flight; except that, if there are no cracks in any of the lower spar boom joints and the extent of the cracking in the top spar boom joints has been reported to B.A.C. (Operating) Ltd. (Weybridge Division) for evaluation and the operator has obtained and presented to the FAA approval for flight from B.A.C. (Operating) Ltd. based upon such evaluation, the airplane may be flown in accordance with FAR 21.197 to a base where replacement with a new top spar boom can be accomplished.
(b) Subsequent to the initial inspection required by (a) the following repetitive inspections must be accomplished.
(1) AIRPLANES FITTED WITH DTD 363 BOTTOM SPAR BOOMS (744 AIRPLANES).
(i) Accomplish ultrasonic or FAA-approved equivalent inspection on all the bottom spar boom joints not later than six months after the date of initial refitment of the taper bolts or subsequent reprotection of the spar boom joints.
(ii) Bottom Outer to Inner Wing spar boom joints that have not been line reamed - Accomplish repetitive ultrasonic or FAA-approved equivalent inspection at intervals not exceeding 18 months, commencing from the date of the initial refitment of the taper bolts or subsequent reprotection of the spar boom joints.
(iii) Bottom Outer to Inner Wing spar boom joints which have been line reamed, or Blueing Checks of the taper bolts has positively established the contact area between the bolt and the bolt hole to be not less than 95 percent including the web plates - Accomplish repetitive ultrasonic or FAA-approved equivalent inspection at intervals not exceeding two years, commencing after the date of initial refitment of the taper bolts or subsequent reprotection of the spar boom joints.
(iv) Bottom Inner Wing to Center Section spar boom joints - Accomplish repetitive ultrasonic or FAA-approved equivalent inspection at intervals not exceeding two years, commencing from the date of initial refitment of the taper bolts or subsequent reprotection of the spar boom joints.
(2) AIRPLANES FITTED WITH L.65 BOTTOM SPAR BOOMS (745D & 810 AIRPLANES).
(i) Accomplish repetitive ultrasonic or FAA-approved equivalent inspection at intervals not exceeding three years, commencing from the date of the last ultrasonic inspection or the subsequent six yearly reprotection of the spar boom joints.
(ii) If cracks are found in any of the lower spar boom joints, replacement with new spar booms is required prior to further flight.
(3) ALL AIRPLANES: TOP SPAR BOOM JOINTS.
(i) Inspect all top spar boom joints, in which the taper bolts have not been retensioned to the revised instruction detailed in the applicable PTL referenced herein, for cracks using ultrasonic methods, or FAA-approved equivalent, at intervals notexceeding six months commencing from the date of the last ultrasonic or FAA-approved equivalent inspection. Airplanes found to have cracks in the top spar boom joints which are within the limits specified in (a)(2)(i) and Sect. II, Part 2 "Limitations" of the applicable PTL referenced herein may be continued in service and must be reinspected in accordance with (b)(4). When cracks are found that exceed the limits of (a)(2)(i) or Section II Part 2 "Limitations" of the applicable referenced PTL, the spar boom must be replaced before further flight in accordance with (a)(3).
(ii) Inspect top spar boom joints in which the taper bolts have been retensioned to the revised instruction detailed in the applicable referenced PTL, for cracks using ultrasonic methods or FAA-approved equivalent, at intervals not exceeding two years commencing from the date of refitment of the taper bolts.
(iii) If, for any reason, an additional ultrasonic inspection has been carried out after retensioning, but before expiration of the two year period, the next ultrasonic inspection must be accomplished within not later than two years from the date of the subsequent inspection. Airplanes found to have cracks in the top spar boom joints which are within the limits specified in (a)(2)(i) and Section II Part 2 "Limitations" of the applicable PTL referenced herein may continue in service and must be reinspected in accordance with (b)(4). When cracks are found that exceed the limits in (a)(2)(i) and Section II Part 2 "Limitations" of the applicable PTL the spar boom must be replaced before further flight in accordance with (a)(3).
(4) On airplanes having cracks in the top spar boom joints which are within the permissible limits of (a)(2)(i) and Section II Part 2 "Limitations" of the applicable PTL referenced herein inspect the affected joint using ultrasonic methods or FAA-approved equivalent as follows:
(i) Where the acceptable defect has a reflectivity of at least 30 percent but not more than 100 percent of the appropriate 5/64 inch flat bottom hole standard, at intervals not exceeding 12 months, or at such periods as are approved by the airplane manufacturer, or the Chief, Aircraft certification Staff, FAA European Region, commencing from the date of the last ultrasonic inspection.
(ii) Where the acceptable defect has a reflectivity above 100 percent but not exceeding 200 percent of the appropriate 5/64-inch flat bottom hole standard, at intervals not exceeding six months or at such periods as are approved by the airplane manufacturer, or the Chief, Aircraft Certification Staff, FAA European Region, commencing from the date of the last ultrasonic inspection.
(iii) Where the acceptable defect has a reflectivity more than 200 percent of the appropriate 5/64-inch flat bottom hole standard, at intervals not exceeding three months or at such periods as are approved by the airplane manufacturer, or by the Chief, Aircraft Certification Staff, FAAEuropean Region, commencing from the date of the last ultrasonic inspection.
(iv) When cracks exceed the limits of (a)(2)(i) and Section II Part 2 "Limitations" of the applicable reference PTL the spar booms must be replaced before further flight in accordance with (a)(3).
(5) In addition to the ultrasonic inspection requirements of (a) and (b)(1) through (4) accomplish ultrasonic or FAA-approved equivalent inspection of the top and bottom spar boom joints when a replacement outer wing is fitted to the airplane. No ultrasonic inspection is necessary when an outer wing is removed and refitted to the same airplane between the specified ultrasonic inspection intervals, provided that bolt tensioning has previously been accomplished in accordance with the applicable PTL referenced herein and provided that the correct ultrasonic inspection cycles have been maintained.
(c) REPROTECTION OF SPAR BOOM JOINTS. Reprotection of wing spar joints at controlled intervals is required and must be accomplished in accordance with the procedure in the applicable referenced PTL. This procedure necessitates the removal of all bolts in each joint to enable a thorough visual inspection for corrosion and cleanliness, both of the bolts and holes. On re-assembly a set of new or reclaimed bolts must be fitted in accordance with Section IV of the subject PTL. After inspection as required by this AD and repair in accordance with the applicable referenced PTL the bolts and joints are to be reprotected and assembled in accordance with the applicable referenced PTL. Following the fitting of the bolts a torque loading check must be accomplished in accordance with Section V of the applicable referenced PTL. Refitment of the bolts must be followed by an inspection of the joint for cracks, using ultrasonic methods or FAA-approved equivalent, prior to further flight. Reprotection of all top and bottom spar boom joints must be carried out on all airplanes when they achieve five years of age, dating from the time of manufacture. On Type 744 airplanes (DTD 363 bottom spar booms) compliance was required by December 31, 1961. On Types 745D and 810 airplanes (L65 bottom spar booms) if this age was achieved before June 30, 1962, compliance was required by that date. Subsequently, repeat the reprotection at intervals of six years. If the spar bolts were retensioned before receipt of Vickers-Armstrongs Cable SS6952 or Issue 4 of the referenced PTL (for 744 and 745D) or Issue 3 of the referenced PTL (for 810) reprotection of all spar joints must be accomplished within six years after the date of the initial retentioning and at subsequent intervals of six years. On airplanes manufactured since January 1961, reprotection of all spar joints is required six years after date of manufacture and repeated at intervals of six years.
(d) INTERFERENCE FITTING OF WING SPAR TAPER BOLTS. Refitment of the bolts must be accompanied by ultrasonic or FAA-approved equivalent inspection. Before being considered serviceable for further use, all taper bolts removed from the airplanes must be treated in accordance with the reclaiming procedure Section VII of the applicable reference PTL. The torque loading figures obtained during refitment of the spar taper bolts must be recorded for each airplane since these figures form the datum point for subsequent periodic torque loading inspections. However, where the original torque loading figures have not been recorded it will be necessary to accept the minimum figures quoted in the applicable referenced PTL for datum purposes at the next check inspection, at which time the torque loading figures must be recorded. Suitable charts on which to record the torque loading values are contained in the applicable referenced PTL's. Following the installation and torque loading check of new or reclaimed bolts as detailed in the applicable referenced PTL the inspections detailed below must be accomplished.
(e) TORQUE LOADING INSPECTIONS OF SPAR BOOM TAPER BOLTS.
(1) OUTER TO INNER WING SPAR BOOM JOINTS - PRIOR TO LINE REAMING THE JOINTS.
(i) Visually inspect the bolts for security not less than 100 hours' nor more than 500 hours' time in service after the time of fitment to the joints.
(ii) Conduct a torque loading inspection not later than six months after the date of refitment of the bolts to ensure that the torque loading values have not deteriorated to a value less than the figure previously recorded. If the torque values are not less than the recorded figures, accomplish next repetitive torque loading inspection within 18 months after the date of refitment of the taper bolts.
(iii) If, on the second repetitive inspection, the torque values are still not less than the recorded figures accomplish next inspection not later than 42 months after the date of refitment of the taper bolts.
(iv) Subsequently, provided the torque values are still not less then the recorded figures accomplish the next repetitive inspection within 66 months from the date of refitment of the taper bolts.
(v) The cycle of inspections required by this paragraph applies only when the torque values remain at not less than the recorded figures at each check. If the readings of any one or more bolts are less than the recorded figure, accomplish rectification in accordance with Section VI of the applicable PTL referenced herein.
(2) OUTER TO INNER SPAR BOOM JOINTS - SUBSEQUENT TO LINE REAMING THE JOINTS.
(i) Visually inspect the bolts for security not less than 100 hours' nor more than 500 hours' time in service after the time of fitment to the joints.
(ii) Conduct a torque loading inspection not later than six months after the date of refitment of the bolts to ensure that the torque loading values have not deteriorated to a value less than the figures previously recorded. If the torque values are not less than the recorded figures, accomplish next repetitive torqueloading inspection within two years after the date of refitment of the taper bolts.
(iii) Subsequently, if torque values remain at not less than the recorded figures accomplish repetitive inspection at intervals of two years.
(iv) The cycle of inspections required by this paragraph applies only when the torque values remain at not less than the recorded figures at each check. If the readings of any one or more bolts are less than the recorded figured, accomplish rectification in accordance with Section VI of the applicable referenced PTL.
(v) The repetitive torque loading inspections required by (d)(2) (ii) and (iii) also apply to those airplanes that have been subject to Blueing Checks of the taper bolts in the holes and it has been positively established that the contact area between the bolt and bolt holes in the top and bottom outer to inner wing joints is NOT LESS THAN 95 PERCENT INCLUDING THE WEB PLATES.
(3) INNER WING TO CENTER SECTION SPAR BOOM JOINTS.(i) Visually inspect the bolts for security not less than 100 hours' nor more than 500 hours' time in service after the time of fitment to the joints.
(ii) Conduct a torque loading inspection not later than six months after the date of refitment of the bolts to ensure that the torque loading values have not deteriorated to a value less than the figure previously recorded. If the torque values are not less than the recorded figures, accomplish next repetitive torque loading inspection within two years after the date of refitment of the taper bolts.
(iii) Subsequently, if the torque values remain at not less than the recorded figures accomplish repetitive inspections at intervals of two years.
(iv) The cycle of inspections required by this paragraph applies only when the torque values remain at not less than the recorded figures at each check. If the reading of any one or more bolts is less than the recorded figure, accomplish rectification in accordance with Section VI of the applicable referenced PTL.
(British Aircraft Corporation (Weybridge Division) Preliminary Technical Leaflet No. 230 Issue 8 (700 Series) and corrigendum (for 744 and 745D airplanes), No. 97 Issue 7 (800/810 Series) and corrigendum (for 810 Series airplanes) or later ARB-approved issue cover this subject.)
This supersedes AD 61-23-05.
This directive effective October 29, 1965.