Cessna C650 first officer reported a pressurization issue caused by improper position of the pack sw...

Attributes
ACN	1530859
Time
Date	201803
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Citation III VI VII (C650)
Operating Under FAR Part	Part 91
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Air Conditioning and Pressurization Pack
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 48 Flight Crew Total 6861 Flight Crew Type 1200
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Flight Deck / Cabin / Aircraft Event Other / Unknown

Narrative:

We had a pressurization issue where we believe a pack wasn't operating properly. This started shortly after takeoff and gave us the 'cab alt high' annunciator. Our primary objective was terrain avoidance so we continued with the course on the departure; but since it was VMC we decided not to continue on. Instead we decided to work the problem while cavu and used our eyes for terrain avoidance while in contact with ATC.ATC wanted us to climb as we had told them we wanted to divert; but that would've required a climb to 17;000 feet which we weren't fully prepared for. We were still trying to troubleshoot the problem and see if we could fix it ourselves and stay in the relatively flat terrain. The checklist never directs the pilot to check the pack switches; and that was the problem the whole time. I reset the actual switches and that fixed our problem.ATC wasn't happy with us not climbing to 17;000 but there was a lot of communication problems in the cockpit with the oxygen masks/ATC/intercom. Basically at the same time the communication problem was figured out; we fixed the pressurization problem by resetting the pack valve switches; and we continued onto our original destination. I hope the manufacturer will address the checklist for 'cab alt high' for the citation 7.

Original NASA ASRS Text

Title: Cessna C650 First Officer reported a pressurization issue caused by improper position of the pack switches that was not resolved by the checklist.

Narrative: We had a pressurization issue where we believe a pack wasn't operating properly. This started shortly after takeoff and gave us the 'Cab Alt High' annunciator. Our primary objective was terrain avoidance so we continued with the course on the departure; but since it was VMC we decided not to continue on. Instead we decided to work the problem while CAVU and used our eyes for terrain avoidance while in contact with ATC.ATC wanted us to climb as we had told them we wanted to divert; but that would've required a climb to 17;000 feet which we weren't fully prepared for. We were still trying to troubleshoot the problem and see if we could fix it ourselves and stay in the relatively flat terrain. The checklist NEVER directs the pilot to check the pack switches; and that was the problem the whole time. I reset the actual switches and that fixed our problem.ATC wasn't happy with us not climbing to 17;000 but there was a lot of communication problems in the cockpit with the oxygen masks/ATC/intercom. Basically at the same time the communication problem was figured out; we fixed the pressurization problem by resetting the pack valve switches; and we continued onto our original destination. I hope the manufacturer will address the checklist for 'Cab Alt High' for the Citation 7.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Cessna C650 first officer reported a pressurization issue caused by improper position of the pack switches that was not resolved by the checklist.