use 1/8-inch rivets at 1-inch spacing in two staggered rows for .025-inch skin. See figures 106 and 107.) For repair of the running light, see figure 111. Cut away and clean the damaged area. Redrill existing holes with a No. 20 drill and use D.T.D 327 - 5/32- inch diameter countersunk rivets. Replace aluminum- alloy 24ST, .020-inch plate and lamp assembly.      e. P-40E Dorsal Fin. - The original P-40E fin is the same in all details as the P-40D tin. To expedite production of the new fin, a tin overlay was

designed to fit over the original tin construction. (See figure l12.)      f. Attachment. - Fin to Stabilizer. - This fitting is built of X4130 steel that is heat-treated to a tensile strength of 90,000 pounds per square inch. Repair to this fitting is not practical because the shock from the impact of shell fire would misalign the channels. These channels have to be parallel within a tolerance of +/- .015 inch.