Aircraft Air Conditioning / Pre-Conditioned Air Unit (5-150 TR), made by MAK Controls & Systems

The MAK Pre-Conditioned Air (PCA) unit supplies temperature-controlled, filtered air to a parked aircraft's cabin environmental control system, allowing the aircraft to maintain a comfortable cabin temperature during ground time without burning APU fuel. The range spans 5 TR to 150 TR of cooling capacity, with standard production models at 30, 60, 65, 70, 110 and 140 TR — sizing that maps directly to aircraft classes from regional jets through to A380 and B747 widebodies. Output air temperature is adjustable from 2°C to 12°C, delivered at 100 to 860 PPM airflow at blower pressures up to 48 inches of water — sufficient to overcome the resistance of the aircraft's ducting and conditioned-air connector. The refrigeration circuit uses Bitzer, J&E Hall or Frascold screw compressors with R134a or R407c refrigerants, and Luve/Luvata heat exchangers for reliable performance in high-ambient environments. Diesel models run Deutz or Cummins Tier 4 Final engines; electric models use a Stamford or Marathon alternator, enabling operation from fixed gate power at airports with electrified gates. The unit is available in towable trailer, self-propelled and passenger-boarding-bridge (PBB) mounted configurations. The PBB-mounted option integrates into the jetway structure, eliminating ramp vehicle movements at the aircraft nose and reducing FOD risk on congested gates. Control is via the MAK GSEM V8-C touchscreen with RDMS telematics for remote temperature monitoring and fault alerting. For GCC operators, the high-capacity end of the range (110–140 TR) addresses the intense cooling load of wide-body aircraft in summer conditions where ambient temperatures regularly exceed 45°C, where APU-less ground handling is a regulatory and fuel-cost priority.