Citation II S2/Bravo (C550)
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
Immediately after rotation; the DOOR SEAL light illuminated. Continued to assigned altitude of 4;000 feet and leveled off to assess and diagnose the issue. We were handed off to Approach Control and told to climb to 10;000 feet. During climb; we observed that the cabin was unable to pressurize properly due to the DOOR SEAL not functioning correctly. We then informed ATC that we would have to stop our climb at 10;000 feet. As we reached approximately 9;500+/- feet; the CAB ALT HI light annunciator illuminated and we immediately requested a lower altitude and a vector back to [departure airport]. ATC gave us a vector. We landed without further incident; and taxied to a holding area where we could further diagnose the problem. We opened and closed the cabin door and the DOOR SEAL light extinguished. We then obtained a new clearance with ATC since the issue appeared to be corrected. The remaining flights went without incident; and upon landing maintenance and Dispatch were notified of the delay and issue with the cabin DOOR SEAL.
[Report narrative contained no additional information.]
CE-550 flight crew reported returning to departure airport when a faulty cabin door seal prevented pressurization.