CE650 captain reported a loss of all pitot-static instruments during cruise.

Attributes
ACN	1490634
Time
Date	201710
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	Citation III VI VII (C650)
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Pitot-Static System
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 67 Flight Crew Total 17893 Flight Crew Type 8000
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Altitude Excursion From Assigned Altitude Deviation - Speed All Types

Narrative:

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.

Original NASA ASRS Text

Title: CE650 Captain reported a loss of all pitot-static instruments during cruise.

Narrative: 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.

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.