"Air Comm strives ceaselessly to design and produce products that
provide optimal comfort, safety, reliability and value for our customers." - Keith Steiner

Service Letters

May be mandatory or at the discretion of the operator. Service Letters give guidance and inspection criteria on known service conditions.

AgustaWestland AW119 Air Conditioning
Air Conditioning
Airbus AS350 Air Conditioning
  • SL-370_RevB
    Air Conditioner Aft Evaporator Blower Motor Connector Upgrade
Airbus EC120 Air Conditioning
  • SL-371_RevA
    Air Conditioner Aft Evaporator & Condenser Blower Motor Connector
Airbus EC130 Air Conditioning
  • SL-352_RevNC
    New Refrigerant Charging Procedure (24 Aug 2007)
  • SL-367_RevA
    Air Conditioner Blower Motor Connector Upgrade
Airbus EC135 Air Conditioning
  • SL-351_RevA
    New Refrigerant Charging Procedure (24 Aug 2007)
Airbus EC145 Air Conditioning
Bell 206 Air Conditioning
  • SL310_RevNC
    Condenser Blower Motor Assembly change
  • SL304_RevNC
    Air Conditioning System Performance Improvement Kit: 206L4 S/N 52118
  • SL311_RevC
    Electrical Change (Prevent potential overload of existing power source)
  • SL313_RevA
    Charging procedures change R134a
  • SL317_RevNC
    Air conditioning system. Temperature Control electrical circuit change 206L4
  • SL316_RevA
    Replacement of Forward Evaporator Blower Wheel & Motor Assy.
  • SL317A_RevNC
    Temperature Control Electrical Circuit change
  • SL323_RevNC
    Replacement of Hi-Output Blower Motor Support Bracket 206L4 & 407 series
  • SL325_RevNC
    Installation of additional R/H forward evaporator in Bell 206 A/B helicopter
  • SL330_RevA
    Forward Evaporator Air Outlet Louver Up-grade & Replacement Procedure 206 & 407
  • SL348_RevNC
    Condenser Scoop Actuator Replacement Procedure 206, 407, & 427
  • SL-365_RevC
    Air Conditioner Blower Motor Connector Upgrade
Bell 206 Heating System
  • SL339_RevNC
    Test procedures for ES26185-1 / -2 (4712-7) solenoid valves
  • SL341_RevNC
    Modification of S-9266EC-30 Particle Separator bleed air port
  • SL206-303_RevNC
    Upgrade Kit - Bell 206 Cabin Heater Aft Heater Outlet Flow Control
  • SL305_RevNC
    Upgrade Kit, Heater Ejector Installations
  • SL306_RevNC
    Cabin Exhaust Vent Blower Modification 206BIII S/N 4324
  • SL328_RevA
    Repair or Replacement of ES26185-1 (4712-7) Firewall shutoff valve
Bell 206 Hydraulic System
  • SL332_RevNC
    Hydraulic System Pump change 206A/B Series
Bell 407 Air Conditioning
  • SL313_RevA
    System charging procedures change R134a
  • SL316_RevA
    Replacement of Forward Evaporator Blower Wheel & Motor Assy.
  • SL323_RevNC
    Replacement of Hi-Output Blower Motor Support Bracket
  • SL330_RevA
    Forward Evaporator Air Outlet Louver Up-grade & Replacement Procedure 206 & 407
  • SL-366_RevC
    Air Conditioner Blower Motor Connector Upgrade
  • SL348_RevNC
    Condenser Scoop Actuator Replacement Procedure 206, 407, & 427
  • SL312_RevNC
    Condenser Blower Motor Assembly change
  • SL314_RevA
    Temperature Control electrical circuit change
  • SL343_RevNC
    Modification to Bell 407 Air Conditioner Belt Tensioning Collar in conjunction with Bell Helicopter Technical Bulletin No. 407-02-35
  • SL349_RevNC
    Inspection of the Bell 407 Air Conditioner Driveshaft Mounted Pulley and Drive Ring assembly
  • SL-329_RevB
    Condenser Scoop Bellcrank Replacement & Adjustment Procedure
Bell 407 Heating System
  • SL-328 _RevA
    Repair or Replacement of ES26185-1 (4712-7) Firewall shutoff valve
  • SL322_RevNC
    Engine Bleed Port Gasket - Engine Compartment Bleed Air System
Bell 412 Air Conditioning
  • SL326_RevNC
    Inspection of 412AC-5040-3 Accumulator, when installed with Aeronautical Accessories Hoist Kit (P/N 412-150-400)
  • SL333_RevNC
    Main Transmission Breather Vent Cap Relocation
  • SL334_RevH
    Compressor/Compressor Mount Up-grade
  • SL336_RevNC
    Hi/Lo Pressure Switch / Receiver Drier Schrader Valve Installation
  • SL-337_RevNC
    Receiver Drier Upper Support Bracket
  • SL344_RevA
    Compressor Speed Reducer Pulley and Bearing (Replacement of Al Idler Pulley by SS Pulley)
  • SL345_RevA
    Compressor Speed Reducer Bearing Replacement
  • SL350_RevNC
    Alternate compressor drive belt installation for the Bell 412CF air conditioner system
  • SL313_RevA
    System charging procedures change R134a
  • SL328_RevA
    Repair or Replacement of ES26185-1 (4712-7) Firewall shutoff valve
  • SL307_RevNC
    Compressor Change
  • SL315_RevNC
    Compressor Inspection Procedures
  • SL-374_RevC
    Compressor Drive Pulley Belt Guard Change
  • SL318_RevNC
    Inspection of Existing Air Conditioning System Condenser Assemblies
  • SL319_RevNC
    Relocation of Air Conditioning System Charging/Service Parts
  • SL320_RevNC
    Removal and Replacement of Air Conditioning System Compressor
  • SL324_RevNC
    Replacement of AFT Evaporator Blower Wheel & Motor Assy.
Bell 427 Air Conditioning
  • SL348_RevNC
    Condenser Scoop Actuator Replacement Procedure 206, 407, & 427
  • SL335_RevA
    Bell 427 Air Conditioner Compressor Drive Belt Replacement
  • SL346_RevNC
    Alternate Compressor Belt
  • SL-369_RevA
    Air Conditioner Blower Motor Connector Upgrade
  • SL329_RevB
    Condenser Scoop Bellcrank Replacement & Adjustment Procedure
Bell 427 Heating System
  • SL342_RevNC
    Change of Heater Bleed Air Shutoff Valve Orientation
Bell 429 Air Conditioning
MD 900 Air Conditioning