Narrative:

While en route we were circumnavigating weather. First officer (first officer) was pilot flying (PF) and I the captain was pilot monitoring. At this time we were IMC and receiving light to moderate turbulence at FL370. While circumnavigating the weather we were well away from any convective activity in what we were painting with our onboard radar. We did notice some 'green' returns on our deviation course; but nothing any more noticeable than that. The turbulence we received was continuous to occasional moderate turbulence at most - flight attendants and passengers were asked to stay seated. As we were exiting the area of turbulence I noticed the IAS was slightly decreasing with a red trend vector decreasing as well. I mentioned to the first officer to add more cruise power since the trend vector was showing a decreasing value. At the time I requested this we were neither climbing nor descending. After adding power and the vector still decreasing I then informed him to set climb power to prevent any further decrease of trend vector and airspeed. We could tell the winds were shifting and neither I nor he were sure if we were getting a slight wind shear at high altitude since the winds were changing quite a bit. At this time I requested lower altitude from ATC to help us increase airspeed. At no time did we get below mach .70. I believe the lowest we indicated was .71 mach.we were given a descent from 370 to 350 and all three airspeed indicators were showing a decreasing speed with a large decreasing trend even though we were in a descent. At this point we recognized we had blocked pitot tubes. Shortly after descending and throughout the descent we received numerous caution msgs: mach trim; stall fail; rudder fault and rudder limiter cautions msgs; 'fadec 2' status messages for engine two and engine one also posted; IAS caution; EFIS comp mon IAS and altitude caution messages (these are the ones I remember). I (captain) became the PF while the first officer ran the QRH procedures. (Please understand that I am trying to recall all messages and events in the best order I can. Not necessarily were they all there together. Sometimes messages appeared; disappeared; and then reappeared. We were running the QRH procedures as best we could for the appropriate messages we saw.) during the descent I was utilizing pitch and power settings best I could and also listening to the air noise over the windscreen to provide the safest descent profile under the circumstances. At no time did I ever feel we were too fast (barber pole) or too slow (near a stall). We [advised] ATC somewhere around FL310; if I remember correctly; and informed ATC we wanted to land in [a nearby airport] since the QRH directed us to do so and it was within close distance to land utilizing normal descent rates; plus it had a long runway which I wanted to utilize for this situation. During the descent the first officer was notifying dispatch we were landing at a divert airport. Also; some messages went away and airspeeds seemed to be normal; but then they would become erroneous again. During the descent my side seemed normal as well as the isi and the first officer's side abnormal; but at lower altitudes then the first officer's airspeed became what seemed normal and concurred with the integrated instrument system (isi) while mine was dropping showing near stall IAS; but the isi; first officer's IAS; and GS from the mfd were all providing data that seemed to elude we were flying safely. At this time we selected the source selector panel air data computer knob to the first officer's side and left it there for the remainder of the flight.while descending through FL250 the autopilot did a rather abrupt wing rocking motion from right to left. I clicked the autopilot off and hand flew the airplane. Sometime later we tried reengaging the autopilot; but it wouldn't engage. Approaching the airport we ensured emergency equipment was standing by as a precaution and we elected to land runway xy for the extra landing length and winds were a little bit of a crosswind; but manageable. Unfortunately we did not have a glide slope to use as a backup and since it was a single FMS head unit we could not enable 'VNAV' since it seemed that used data from my side and that function was not usable. The first officer then began calling out altitude and distance information to help me stay on a 3.0 degree glide path until I was able to utilize the VASI. We landed using flaps 20 (QRH directed with rudder limiter fault) and taxied off the runway to the gate without any additional problems.there were numerous threats in the situation. Weather; erroneous instruments (IAS); numerous message both caution and fault messages. Fortunately we never were in an undesired aircraft state that I knew of other than trying to figure out what airspeed we were using. We also backed up ground speeds with ATC to do our best to ensure we were flying at safe speeds for the pitch and power settings used. As in any event we can always look back and think 'I could have done this or that better'; hindsight is always 20/20. What was an exceptional factor to flying this airplane safely was the use of good CRM. The first officer was exceptional in all aspects in the way he helped me and ensured I wasn't forgetting to take care of necessary steps. I am very very thankful for the training has put into this high altitude pitot tube icing training as well as teaching solid CRM fundamentals and concepts to safely fly airplanes to the best of our abilities.

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Original NASA ASRS Text

Title: A CRJ-700 flight crew reported what appeared to be pitot icing at FL370 in IMC. The equipment affected were both airspeed/Mach systems; Integrated Standby Instruments; FADEC; RUD LIMITER; STALL Warning; MACH TRIM and EFIS COMP MON. The crew diverted to the nearby airport for an uneventful landing. Descending through FL200 in VMC partial equipment functionality returned.

Narrative: While en route we were circumnavigating weather. First Officer (FO) was Pilot Flying (PF) and I the Captain was Pilot Monitoring. At this time we were IMC and receiving light to moderate turbulence at FL370. While circumnavigating the weather we were well away from any convective activity in what we were painting with our onboard radar. We did notice some 'green' returns on our deviation course; but nothing any more noticeable than that. The turbulence we received was continuous to occasional moderate turbulence at most - Flight Attendants and passengers were asked to stay seated. As we were exiting the area of turbulence I noticed the IAS was slightly decreasing with a red trend vector decreasing as well. I mentioned to the FO to add more cruise power since the trend vector was showing a decreasing value. At the time I requested this we were neither climbing nor descending. After adding power and the vector still decreasing I then informed him to set Climb power to prevent any further decrease of trend vector and airspeed. We could tell the winds were shifting and neither I nor he were sure if we were getting a slight wind shear at high altitude since the winds were changing quite a bit. At this time I requested lower altitude from ATC to help us increase airspeed. At no time did we get below Mach .70. I believe the lowest we indicated was .71 Mach.We were given a descent from 370 to 350 and all three airspeed indicators were showing a decreasing speed with a large decreasing trend even though we were in a descent. At this point we recognized we had blocked pitot tubes. Shortly after descending and throughout the descent we received numerous caution Msgs: Mach trim; Stall fail; rudder fault and rudder limiter cautions Msgs; 'Fadec 2' status messages for engine two and engine one also posted; IAS caution; EFIS Comp Mon IAS and ALT caution messages (these are the ones I remember). I (Captain) became the PF while the FO ran the QRH procedures. (Please understand that I am trying to recall all messages and events in the best order I can. Not necessarily were they all there together. Sometimes messages appeared; disappeared; and then reappeared. We were running the QRH procedures as best we could for the appropriate messages we saw.) During the descent I was utilizing Pitch and Power settings best I could and also listening to the air noise over the windscreen to provide the safest descent profile under the circumstances. At no time did I ever feel we were too fast (barber pole) or too slow (near a stall). We [advised] ATC somewhere around FL310; if I remember correctly; and informed ATC we wanted to land in [a nearby airport] since the QRH directed us to do so and it was within close distance to land utilizing normal descent rates; plus it had a long runway which I wanted to utilize for this situation. During the descent the FO was notifying dispatch we were landing at a divert airport. Also; some messages went away and airspeeds seemed to be normal; but then they would become erroneous again. During the descent my side seemed normal as well as the ISI and the FO's side abnormal; but at lower altitudes then the FO's airspeed became what seemed normal and concurred with the Integrated Instrument System (ISI) while mine was dropping showing near stall IAS; but the ISI; FO's IAS; and GS from the MFD were all providing data that seemed to elude we were flying safely. At this time we selected the Source selector panel ADC knob to the FO's side and left it there for the remainder of the flight.While descending through FL250 the autopilot did a rather abrupt wing rocking motion from right to left. I clicked the autopilot off and hand flew the airplane. Sometime later we tried reengaging the autopilot; but it wouldn't engage. Approaching the airport we ensured emergency equipment was standing by as a precaution and we elected to land runway XY for the extra landing length and winds were a little bit of a crosswind; but manageable. Unfortunately we did not have a glide slope to use as a backup and since it was a single FMS head unit we could not enable 'VNAV' since it seemed that used data from my side and that function was not usable. The FO then began calling out altitude and distance information to help me stay on a 3.0 degree glide path until I was able to utilize the VASI. We landed using flaps 20 (QRH directed with Rudder Limiter Fault) and taxied off the runway to the gate without any additional problems.There were numerous Threats in the situation. Weather; Erroneous instruments (IAS); numerous message both caution and fault messages. Fortunately we never were in an undesired aircraft state that I knew of other than trying to figure out what airspeed we were using. We also backed up ground speeds with ATC to do our best to ensure we were flying at safe speeds for the pitch and power settings used. As in any event we can always look back and think 'I could have done this or that better'; hindsight is always 20/20. What was an exceptional factor to flying this airplane safely was the use of good CRM. The First Officer was exceptional in all aspects in the way he helped me and ensured I wasn't forgetting to take care of necessary steps. I am very very thankful for the training has put into this high altitude pitot tube icing training as well as teaching solid CRM fundamentals and concepts to safely fly airplanes to the best of our abilities.

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.