T. SERVICE BULLETIN 10-JUN-1999 MOS - (s) SB 737-09-1133 AIRBORNE AUXILIARY POWER- AUXILARY POWER UNIT AIR INLET - AUXILARY POWER UNIT FLAP AND VORTEX GENERATOR ASSEMBLY MOSIFICATION. SERVICE BULLETIN MOS 22-SEP-2005 SB 737-09-1133 RI 21-SEP-2007 SB 737-09-1133 R2 26-JAN-2009 SB 737-09-11