What was found
WITH WING ANTI-ICE ON, LOUD THUMP HEARD ON LEFT SIDE LEFT WING LE OVHT LIGHT ILLUMINATED. CLOSED LEFT ISOLATION VLV, SHUTOFF NR 1 AND NR 2 BLEED. WING OVHT LIGHT WENT OUT. FOUND MAIN PNEU SUPPLY DUCT WITH DAMAGED FLANGES AND CLAMPS, 2 EA LOWER SKIN PANELS HAVE EXTENSIVE HEAT DAMAGE. COMPLIED W/INTERIM REPAIR PER EO B747-5720-28529A. PERM REPAIR DUE BY 5/17/08. LT WING L/E PNEUM DUCT REMOVED FROM STA 170-630 & 170-365. INSTALLED PNEU DUCT PER 36-11-00. LEAKS CHECKS GOOD.