AIRCRAFT USE OF FUELS CONTAMINATED WITH DYE. SERVICE LETTER RECOMMENDED MOS I6-APR-2012 SL 737-SL-28-055 DESIGN IMPROVEMENT FOR PITCH AND ROLL INCLINOMETERS TO PREVENT CRACKING OF GLASS TUBE, SERVICE INFORMATIONAL LETTER I8-JUN-1999 MOS - (s) SL 737-SL-28-055 REV. A DESIGN IMPROVEMENT FOR PITCH AND