What was found
AIRCRAFT WAS GROUNDED: ONCE AT FLIGHT IDLE ON THE DESCENT THROUGH 17000 ABNORMAL ODOR NOTICED IN FLIGHT DECK. NOTHING NOTED IN CABIN. COMPLIED WITH QRH15-38, AND ODOR DISSIPATED WITHIN SEVERAL MINUTES. TURNED PACK1 AND CROSS BLEED BACK TO AUTO AND ODOR CAME BACK. COMPLETED FLIGHT WITH PACK 1 OFF AND CROSS BLEED SHUT AND NO FURTHER ORDOR NOTICED. MAINTENANCE ACCOMPLISHED JC 26L00021001 AND JC 26L00021013. NO LONGER ABNORMAL ODOR PRESENT AT THIS TIME, A/C OK FOR SERVICE.