Narrative:

At altitude with captain flying; we received EFIS comparator monitor for indicated airspeed. We noted the difference in indicated airspeed and the message cleared and reappeared several times. Shortly; ATC gave a descent of about 2000 ft. In the descent; we noted that first officer's side showed appropriate increase in indicated airspeed as the descent was initiated without a thrust reduction. The captain's side showed a decrease in indicated airspeed at the same time. We switched control on the fcp and transponder and I became PF. During the multiple stepdowns we received from ATC; the indicated airspeed became an increasingly greater difference. Also; we received 'temperature miscompare' on the FMS message line and the mach trim caution message came on and would not clear. We received a crossing restriction from ATC that would require a large vsi to meet. As soon as the descent was initiated; the yoke began to oscillate at a rate we thought excessive. We decreased the rate of descent and notified ATC we could not comply with the cross. The lower we descended the information on captain's pfo agreed again with first officer's side. On the approach and the rollout the speeds were once again off by 10-15 KIAS. At the gate in jax; the mechanic said there was water dropping from the captain's air data computer. As we waited to hear from maintenance if they could fix the problem. We began brainstorming about the incident. The captain said that on the takeoff roll my '100 KTS' call was made when his airspeed indicated only 90 KTS. This started me thinking that on the leg before from yul-lga the captain called '100 KTS' late and also on the landing roll his '70 KTS' call was way early. Since I flew from yul-lga and we were not as high; we did not recognize a problem. After it happened with captain as PF; I started thinking about the prior leg. Apparently the aircraft was delayed in cvg due to heavy rain. The aircraft flew to yul and was shut down approximately 10 mins between crews.

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Original NASA ASRS Text

Title: CRJ-200 FLT CREW HAS ANNUNCIATORS SHOW INDICATED AIRSPD; MACH TRIM; TEMP AND VSI MALFUNCTION ON THE CAPT'S SIDE. FLT CREW SWITCHES CTL TO FO SIDE OF COCKPIT AND CONTINUE.

Narrative: AT ALT WITH CAPT FLYING; WE RECEIVED EFIS COMPARATOR MONITOR FOR INDICATED AIRSPD. WE NOTED THE DIFFERENCE IN INDICATED AIRSPD AND THE MESSAGE CLRED AND REAPPEARED SEVERAL TIMES. SHORTLY; ATC GAVE A DSCNT OF ABOUT 2000 FT. IN THE DSCNT; WE NOTED THAT FO'S SIDE SHOWED APPROPRIATE INCREASE IN INDICATED AIRSPD AS THE DSCNT WAS INITIATED WITHOUT A THRUST REDUCTION. THE CAPT'S SIDE SHOWED A DECREASE IN INDICATED AIRSPD AT THE SAME TIME. WE SWITCHED CTL ON THE FCP AND XPONDER AND I BECAME PF. DURING THE MULTIPLE STEPDOWNS WE RECEIVED FROM ATC; THE INDICATED AIRSPD BECAME AN INCREASINGLY GREATER DIFFERENCE. ALSO; WE RECEIVED 'TEMP MISCOMPARE' ON THE FMS MESSAGE LINE AND THE MACH TRIM CAUTION MESSAGE CAME ON AND WOULD NOT CLEAR. WE RECEIVED A CROSSING RESTRICTION FROM ATC THAT WOULD REQUIRE A LARGE VSI TO MEET. AS SOON AS THE DSCNT WAS INITIATED; THE YOKE BEGAN TO OSCILLATE AT A RATE WE THOUGHT EXCESSIVE. WE DECREASED THE RATE OF DSCNT AND NOTIFIED ATC WE COULD NOT COMPLY WITH THE CROSS. THE LOWER WE DSNDED THE INFO ON CAPT'S PFO AGREED AGAIN WITH FO'S SIDE. ON THE APCH AND THE ROLLOUT THE SPDS WERE ONCE AGAIN OFF BY 10-15 KIAS. AT THE GATE IN JAX; THE MECH SAID THERE WAS WATER DROPPING FROM THE CAPT'S ADC. AS WE WAITED TO HEAR FROM MAINT IF THEY COULD FIX THE PROB. WE BEGAN BRAINSTORMING ABOUT THE INCIDENT. THE CAPT SAID THAT ON THE TKOF ROLL MY '100 KTS' CALL WAS MADE WHEN HIS AIRSPD INDICATED ONLY 90 KTS. THIS STARTED ME THINKING THAT ON THE LEG BEFORE FROM YUL-LGA THE CAPT CALLED '100 KTS' LATE AND ALSO ON THE LNDG ROLL HIS '70 KTS' CALL WAS WAY EARLY. SINCE I FLEW FROM YUL-LGA AND WE WERE NOT AS HIGH; WE DID NOT RECOGNIZE A PROB. AFTER IT HAPPENED WITH CAPT AS PF; I STARTED THINKING ABOUT THE PRIOR LEG. APPARENTLY THE ACFT WAS DELAYED IN CVG DUE TO HVY RAIN. THE ACFT FLEW TO YUL AND WAS SHUT DOWN APPROX 10 MINS BTWN CREWS.

Data retrieved from NASA's ASRS site as of January 2009 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.