AD 78-23-13

78-23-13 BRITISH AIRCRAFT CORPORATION: Amendment 39-3350. Applies to Viscount Model 744, 745D, and 810 Series airplanes, certificated in all categories.

Compliance is required as indicated.

The following parts are affected by this AD:

700 Series 800 Series

10" Oleos 14" Oleos

Gland Nut 70050-317 72450-69 81050-69 Locking Plate

72450-71 81050-71 Locking Screw 70050-259

To ensure the security of the gland nut and locking plate/locking screw combination and prevent detachment of the gland nut of the main landing gear shock absorber struts, accomplish the following:

(a) Within the next 25 landings after the effective date of this AD and thereafter at intervals not to exceed 25 landings from the last inspection until the inspection required by paragraph (c) of this AD is performed, visually inspect the gland nut and locking plate/locking screw combination as installed for security and satisfactory locking in accordance with paragraph 2.2 of the "Accomplishment Instructions" of British Aircraft Corporation Preliminary Technical Leaflet (PTL) No. 299 (700 Series) or PTL No. 168 (800 Series), as applicable, both at Revision 3, dated January 12, 1977, or an FAA-approved equivalent.

(b) If, during any of the inspections required by paragraph (a) of this AD, the gland nut is found to be loose or not adequately locked, before further flight, remove the gland nut and inspect the thread form in accordance with paragraph (c) of this AD.

(c) Within 500 landings after the effective date of this AD, unless already accomplished within the last 2,500 landings, and thereafter at intervals not to exceed 3,000 landings, remove the gland nut and inspect the condition of the threads in accordance with the criteria established in paragraph 2.2.2 of British Aircraft Corporation PTL No. 299 (700 Series) or PTL No. 168 (800 Series), as applicable, both at Revision 3, dated January 12, 1977, or an FAA- approved equivalent.

(d)If, during any inspection performed in accordance with paragraph (c) of this AD, the thread form of the gland nut is found unacceptable under the criteria referenced in paragraph (c) of this AD, before further flight, replace the gland nut with a serviceable part of the same part number found acceptable under those criteria.

(e) If, during any of the inspections required by this AD, a locking plate is found worn or fractured, before further flight, replace the locking plate with a serviceable part of the same part number. Replacement locking plates may be installed with the shock absorber strut intact by parting the plate as illustrated in Figure 1 of British Aircraft Corporation PTL No. 299 (700 Series) or PTL No. 168 (800 Series), as applicable, both at Revision 3, dated January 12, 1977, or an FAA-approved equivalent.

This amendment becomes effective December 18, 1978.