A Mechanic and Inspector report an MD-80 Structural Repair Manual (SRM) illustration does not accurately represent the requirement to have flush repair internal doublers pass under longerons; modified shear-ties and frames for a left alternate static port external fuselage skin repair in an RVSM area.
Synopsis
A Mechanic and Inspector report an MD-80 Structural Repair Manual (SRM) illustration does not accurately represent the requirement to have flush repair internal doublers pass under longerons; modified shear-ties and frames for a left alternate static port external fuselage skin repair in an RVSM area.
Narrative
I performed a repair on an MD-80 aircraft at the left hand [Alternate] static port area. The repair was performed per Structural Repair Manual (SRM) figure; outlining a flush repair concerning the [fuselage] production skin overlap. In this particular repair you have to use what is called the 'brick method'; where you have an internal doubler that connects the existing skin and the new skin. The figure illustrates that the bricks start and stop at the longerons and shear-ties/frames with continuous finger doublers running under all related structure. After talking to a co-worker and looking closer at SRM illustration; we discovered that the bricks are supposed to pass under the shear-ties/frames with modified/repaired shear-ties and frames. The SRM figure does not mention of altering/modifying or performing repairs to the affected shear-ties/frames. And the SRM illustration does not include a view of the modified shear-ties/frames. In the SRM; near the shear-tie/frame area; the dashed/jagged lines and fastener legend /identifying markings do not accurately represent performing this repair.
Second reporter narrative
While buying-off [signing for] the final installation of the repair; I incorrectly interpreted the Structural Repair Manual (SRM) repair drawing. The repair brick doubler as is terminates at the frame shear-tie. The repair brick doubler should slide under the shear-tie. The SRM drawing was difficult to interpret due to several [referenced] stacked pieces of material and the cut lines as shown. Suggest revising SRM drawing to make it clearer to see at the frame shear-tie location; also adding general notes to clarify [in SRM].
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.