What was found
THE 315W1176-25 AFT COWL SKIN HAS AN AREA OF DISCOLORATION, POSSIBLE OVERHEAT CENTERED 5.0 INCHES FROM THE AFT EDGE OF THE SKIN AND 4.25 INCHES FROM THE LOWER EDGE OF THE SKIN. THE DISCOLORATION MEASURES 2.5" X 1.5". HEAT DAMAGE ANALYSIS PER SRM 51-20-03 REVEALED THE FOLLOWING, DEFECT: CONDUCTIVITY AND HARDNESS OUT OF RANGE. MATERIAL: 2024-T62 ALUMINUM. ACTUAL CONDUCTIVITY (MAX OF 35 READINGS): 42.3 % IACS (17" FROM AFT EOP; 19" FROM UPPER EOP). IDEAL CONDUCTIVITY: 36.0--40.0 % IACS. ACTUAL HARDNESS (MAX OF 5 READINGS): 66.0 HRB (2 INCHES FROM THE AFT EOP; 18.5 INCHES FROM UPPER EOP). IDEAL HARDNESS: 72.0--86.0 HRB. LOCATION: ENTIRE AFT COWL SKIN. TOTAL MEASUREMENTS: 35 CONDUCTIVITY READINGS; MAX, 42.3 % IACS; MIN, 40.3 % IACS; MEDIAN, 41.00 % IACS; MODE, 40.90 % IACS; MEAN, 41.28 % IACS; STD DEV, 0.86 % IACS.