Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Workload; Troubleshooting; Time Pressure; Situational Awareness
Aircraft Equipment Problem Critical
Air Traffic Control Provided Assistance; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport
Aircraft
We were on a Part 91 ferry flight. On climb out we noticed the ground idle annunciation light was illuminated which we concluded was not normal as the ground idle is on a squat switch and shouldn't be on in flight. We further discussed other system items which would possibly cause the issue. In addition we noticed that the takeoff V speeds were still showing on the airspeed indicator which should have been cleared out after takeoff. ATC cleared us up to FL390 and we were crossing our first fix. We tried cycling the ground idle switch during this time and were in the mid teens. The ground idle annunciation remained illuminated. Shortly after this the Captain noticed that our cabin was not pressurizing; as the cabin altitude was not increasing nor was the cabin rate increasing. He selected the cabin rate knob to high to try and get the cabin to pressurize. Shortly after; the cabin rate immediately went to approximately 6;000 fpm. He said lets get our oxygen masks on. We put them on and at this time we were at approximately FL220. Suddenly the master warning illuminated along with a cabin decompression annunciation. He disconnected the autopilot and leveled off and said lets advise ATC. I advised ATC and requested a return to our origin. ATC gave us a descent to 10;000 ft. with direct to the airport. Once we accomplished memory items for cabin decompression and emergency descent we ran the emergency checklist and returned with no further issues. I believe we handled the situation appropriately by advising ATC and going to a lower altitude and returning to our origin airport. Once we reached 10;000 ft. the cabin decompression annunciation extinguished and we landed with no further issues.
Cessna V/Ultra Pilots reported a malfunction of the air/ground squat switch and unable to pressurize the aircraft.