Lufthansa / Structures Engineering

A) question to paragraph (t)(1) DLH's understanding is, that the new Zones 4 and 5 are not physically new, but derived from former Zones 1 through 3 of the initial release of the SB. Therefore, inspections performed in all Zones 1,2 and 3 in accordance with SB Rev 0, should be acceptable for compliance with the requirements of paragraph (q) and (r). B) additional grace period Areas that were shifted to a more critical zone must be inspected within 4500 FC after effective date of AD or before reaching the applicable zonal inspection threshold, whichever occurs last. For any of these new critical zones that are inspected in accordance with the requirements of the full LRTS because of previous scribe line findings in the adjacent zone on the same lap splice between two butt joints, it would be beneficial to continue the full LRTS beyond the 4500FC grace period to reach the next heavy maintenance event to do the inspection. This may only valid for aircraft and areas where requirements of the Full LRTS is applied. C) no zones FAA may consider a wording how to proceed with scribed areas that have become "no zone" and are inspected in accordance with SB 737-53A1266 LRTS. The scribe damage in the "no zone" may out be of the SRM limit and need to be repaired prior to next flight, because the LRTS is not applicable any more.