Crj-900 captain reported his airspeed indicator became unreliable in cruise flight. Crew selected al...

Narrative:

We were cruising at FL360 and at a filed airspeed of M.80. We received a clearance to climb to FL370 for traffic. Shortly after level off at the new altitude we received an EFIS comp mon caution message on our EICAS along with yellow IAS boxes on each pfd; while simultaneously receiving another climb instruction to FL380 for additional traffic from ATC. First officer started running the QRH while I resumed flying. The captain airspeed indication displayed M.828 while the first officer displayed M.77 and decreasing. We advised ATC that we required a lower altitude while we were working through a checklist for erroneous airspeed indications. As I descended the a/C and first officer ran the QRH; the captain airspeed indicator was approaching max speed ('barber pole') while the first officer and standby airspeed indicators both displayed M.72. At this point we ascertained that the first officer's indications were more accurate and corrected power to regain airspeed towards M.77. Per QRH procedures we selected ADC2 as the air data source on our source select panel and requested a further lower altitude of FL280 as we were no longer capable of rvsm. After verifying sufficient fuel and advising dispatch we continued safely to [destination].

Original NASA ASRS Text

Title: CRJ-900 Captain reported his airspeed indicator became unreliable in cruise flight. Crew selected alternate Air Data Computer and continued to destination.

Narrative: We were cruising at FL360 and at a filed airspeed of M.80. We received a clearance to climb to FL370 for traffic. Shortly after level off at the new altitude we received an EFIS COMP MON Caution message on our EICAS along with yellow IAS boxes on each PFD; while simultaneously receiving another climb instruction to FL380 for additional traffic from ATC. First Officer started running the QRH while I resumed flying. The Captain Airspeed Indication displayed M.828 while the First Officer displayed M.77 and decreasing. We advised ATC that we required a lower altitude while we were working through a checklist for erroneous airspeed indications. As I descended the A/C and First Officer ran the QRH; the Captain Airspeed Indicator was approaching max speed ('barber pole') while the First Officer and Standby Airspeed Indicators both displayed M.72. At this point we ascertained that the First Officer's indications were more accurate and corrected power to regain airspeed towards M.77. Per QRH procedures we selected ADC2 as the Air Data source on our Source Select Panel and requested a further lower altitude of FL280 as we were no longer capable of RVSM. After verifying sufficient fuel and advising Dispatch we continued safely to [destination].

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.

Attributes
ACN	1495028
Time
Date	201711
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Regional Jet 900 (CRJ900)
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Airspeed Indicator
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Speed All Types

Crj-900 captain reported his airspeed indicator became unreliable in cruise flight. Crew selected alternate air data computer and continued to destination.