Citation III; VI; VII (C650)
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor
Flight Crew Last 90 Days 67; Flight Crew Total 17893; Flight Crew Type 8000
Human-Machine Interface; Situational Awareness; Troubleshooting
Aircraft Equipment Problem Critical; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types
Aircraft Equipment Problem Dissipated; Flight Crew FLC Overrode Automation; Flight Crew Overcame Equipment Problem
Aircraft; Human Factors
We experienced a slow degradation of the Captain's pitot static system. Eventually we experienced a partial shutdown of the First Officer's pitot static system. Our first indication was that the autopilot acted as if it was in a mountain wave but we were over the ocean above weather. The First Officer's instruments initially helped us get back on track but as we noted on our iPads using a Stratus S2 with synthetic vision that those instruments were suspect too. Using pitch power and the iPad for vertical speed monitoring and not doing anything aggressive; we descended out of RVSM altitudes. Somewhere around FL220 we regained first the copilot's side and then the captain's side. An uneventful final descent and landing followed.
The reporter stated that at FL410 they noticed the pitot/static system had an issue. They received warnings for the airspeed; altitude; vertical speed; and the autopilot. They disconnected all auto functions and hand flew the aircraft. The airspeed was indicating Mach .91 and all the indicators were completely unreliable. They finally regained control and some indication by FL220. They used an iPad for vertical speed monitoring.The reporter stated that prior to this flight the aircraft had been washed by a contract service. After the flight they found soapy water in the pitot/static system. After the wash; the pitot/static plumbing was not drained and may not have been covered while being washed. The pitot/static drains are not easily accessible. To gain access to the pitot/static drains; it's required that Maintenance removes panels on each side of the aircraft.
CE650 Captain reported a loss of all pitot-static instruments during cruise.