Citation II S2/Bravo (C550)
Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 100; Flight Crew Total 4635; Flight Crew Type 1215
Communication Breakdown; Confusion
ATC Issue All Types; Aircraft Equipment Problem Less Severe
Flight Crew Returned To Departure Airport
Procedure; Aircraft
Shortly after takeoff we began running the After Takeoff Checklist and noticed that the red 'Gear Unlocked' light remained on after gear retraction. I then noticed that the 'Hyd Press On' annunciator light light remained on as well - informing us that the hydraulic system remained pressurized. Knowing that we cannot continue flight with the hydraulic system pressurized we quickly ran the appropriate emergency checklists which led us to believe that while our landing gear was operating normally; the microswitch used to open the hydraulic system was malfunctioning. After quickly diagnosing the problem; we advised Approach that we'd like to return for a precautionary landing. They asked if we needed further assistance; at which point; we advised that we were fine and didn't need any special assistance with the matter. We then cancelled the IFR flight plan and joined the left traffic pattern; performed the appropriate checklists and landed without incident. The entire flight took less than 6 minutes from the time we took off.Shortly after landing the Airport Authority began making phone calls to the airport asking if we were okay. I then was approached by an Airport Authority Official asking if we were okay and preceded to tell me that Approach was concerned about our safety. I told him that we were fine and that we relayed the same message to Approach while on frequency. I've heard nothing from either party since.I'm writing this report because there was a clear breakdown in communication due to the quick nature of this emergency. We made every attempt to address any concerns that ATC may have had by informing them that we did not need special services and that were planning a normal landing as a precautionary measure only. I'm concerned that ATC used valuable resources and time making extra efforts to contact us when such efforts were not needed.
When the associated hydraulic system improperly remained pressurized after landing gear retraction the flight crew of a C550 made a precautionary return and landing at their departure airport.  Although they had not declared an emergency they were met by airport officials inquiring as to their well being and aircraft status.  The reporter felt such efforts were unnecessary.