ON IMPROVEMENTS TO INFORMATIONAL THE CARRIAGE AND GIMBAL ASSEMBLIES.. SERVICE LETTER MOS 07-AUG-2001 - (s) 51 737-SL-57-078 LOOSE FASTNERS IN THE AFT FLAP PROGRAMMING TRACKS. SERVICE LETTER INFORMATIONAL MOS I4-NOV-2001 - (s) 51 737-SL-57-079 WING TRAILING EDGE - INBOARD FIXED PANEL INTERFERENCE WITH GROUND SPOILER