May - Cessna

---------------------------------------------------650------------------------------------------------Number: SB650-23-20-R2Type: OptionalTitle: Radio Management Unit (RM855) InstallationEffectivity: 650-0001 thru -7119Description: The Radio Management Unit (RMU) (RM850) is obsolete and will need to be replaced with the RMU(RM855). This optional service bulletin provides parts and instructions to replace the RM850 with the RM855.Revision 2 changes the compliance, allowing the replacement of a single RMU, but does not affect airplanes thathave previously complied with the service bulletin.---------------------------------------------------750------------------------------------------------Number: SB750-29-14-R1Type: MandatoryTitle: Engine Pylon Hydraulic Tube ImprovementEffectivity: 750-0039 thru -0306Description: The existing hydraulic tube can chafe the bleed air pylon tube heat shield. This mandatory servicebulletin provides parts and instructions to replace the existing hydraulic tube with a new one. Revision 1 makessome changes to accomplishment instructions, but does not affect airplanes that have previously complied withthis bulletin.Number: SB750-53-33Type: OptionalTitle: Ram Air Drip Tray ImprovementEffectivity: 750-0001 thru -0308 with ACSS TCAS 2000 InstalledDescription: The existing ram air drip tray can crack, allowing water to drip on components below. This optionalservice bulletin provides instructions to replace the existing drip tray with an improved new one. This bulletin canbe accomplished at the discretion of the owner.page 11www.citationservice.com