Citation X (C750)
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Situational Awareness; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance
Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
After departure PBI; SLIDZ1 Runway 10L; part 91 trip; aircraft not pressurizing. We leveled off at 7000 feet to work the problem and decided to return as cabin would not pressurize. While holding at SLIDZ1; west of PBI to burn fuel for landing weight; we already had slats/flaps 5; speed brakes deployed and gear down to create max fuel burn. Amber CAS (Crew Alerting System) message 'HYD VOLUME A LOW' appeared. We had 6-11% volume in the A system. We ran the checklist; notified ATC we are now [requesting priority handling]; notified Dispatch; briefed each other; briefed passengers and landed Runway using emergency braking. Came to complete stop on Runway. CFR (Crash fire rescue equipment) and [FBO] tug met us; placed chalks and tugged us off runway without incident.
C750 Captain reported pressurization failure causing a return to departure airport.