Ground power unit guide for the Bombardier Challenger 300/350. High-output 28V DC GPU specs and recommended equipment for the super-midsize business jet.
About the Bombardier Challenger 300/350
The Bombardier Challenger 300 and its upgraded successor, the Challenger 350, represent the super-midsize jet category — large enough for transcontinental range and a stand-up cabin, powerful enough to demand serious ground power infrastructure. These aircraft sit at the point where GPU selection crosses from "nice to have a portable" to "you need real equipment or you're not starting this airplane."
GPU Requirements
The Challenger 300/350's twin Honeywell HTF7350 turbofans draw 3,000 to 4,000 amps at peak during ground starts. This puts the Challenger firmly in TRU territory — while large battery GPUs can technically deliver this current, the sustained draw of starting two high-bypass turbofans in sequence pushes even lithium battery packs to their limits. Continuous power demands are equally significant: the Collins Pro Line 21 avionics, environmental control system, and cabin management system draw 400 to 500 amps during ground operations. Maintenance tasks like avionics updates and system checks can run for hours, requiring sustained continuous power.
Cold Weather Considerations
Super-midsize jets at northern airports in winter are the most demanding GPU scenario in business aviation. Peak draws approaching 4,000A at temperatures below -20°C are common. FBOs serving ski-resort airports (Aspen, Vail/Eagle, Jackson Hole) invest in high-capacity TRUs specifically for Challenger-class aircraft.
Recommended Ground Power Units
TRU
ITW GSE 2400T
Mains-powered TRU delivering up to 2,400A peak. For Challenger operations, two units can be paralleled for 4,800A combined peak — the standard FBO approach at high-traffic airports.
Combination GPU
Powervamp Coolspool 600
3,200A peak with 500A continuous. Approaches the Challenger 300's minimum requirements and works well for the lighter Challenger 300 in temperate conditions.
Diesel GPU
Hobart GPU-4120
Diesel-powered mobile GPU delivering 28V DC at 3,500A+ peak. Used at airports where fixed TRUs aren't available at every parking position. Towable to the aircraft's external power receptacle.
Need help choosing? See our GPU Sizing Guide for a step-by-step approach to matching ground power equipment to your aircraft, or compare options in our Best GPU 2026 roundup.
Related Equipment
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Frequently Asked Questions
Can a portable battery GPU start a Challenger 300?
Marginally. The Challenger 300 requires 3,000A+ peak, which is at the absolute limit of the largest lithium battery GPUs. In cold weather, a battery GPU alone may not suffice. For reliable Challenger starts, a mains-powered TRU or diesel GPU is strongly recommended.
What GPU do Challenger 350 FBOs use?
Most FBOs serving Challenger-class aircraft use mains-powered TRUs (ITW GSE 2400, Powervamp, or equivalent) rated at 2,400A or higher, often paralleled for additional capacity. Diesel GPUs from Hobart and TLD supplement fixed installations.
Is the Challenger 350 GPU connector different from the 300?
No. Both the Challenger 300 and 350 use the standard NATO 3-pin 28V DC external power receptacle. The 350's HTF7350 engines draw slightly more current than the 300's HTF7000, but the connector is identical.