From Beechcraft Service Bulletin # MTB-52-01 Revision Date: October 8, 2018 Date of Original: April 12, 2018 Revision Purpose: To expand Effectivity. Revision Compliance: NO EFFECT. Airplanes previously modified by this service bulletin are not affected by this revision. Doors – Inside Airstair Door Handle Snap Ring Modification Effectivity: King Air 90 (applicable variants within…