2025-05 · NASA ASRS report 2247478
Air Carrier CRJ-900 crew reported an 'EFIS COMP MON' warning during descent due to a degraded AHRS system. Crew landed safely after their second hand flown approach to minimums.
During Decent into ZZZ we received an EFIS (Electronic Flight Instrument System) COMP (Comparator) MON (Monitor) caution. We ran the appropriate QRH. While running the QRH we had a 154 knot crosswind giving the impression that the CA side heading indicator was the correct side. We followed the checklist and the EFIS COMP MON message cleared. While joining the final approach fix the autopilot kicked off. I began to hand fly the approach. I became unstable and Approach canceled our approach clearance and asked us to fly a north heading. While attempting to do so my PFD (Primary Flight Display) began to go on and off. A red MAG (Magnetic) flag populated on my PFD and while being asked to fly different headings by ATC my FO and I tried to determine what information was to do and which was bad. We [requested priority handling] with ATC and I began to fly off the standby and the compass. We began to run the QRH for an AHRS failure. After completion of the checklist we determined we had the proper amount of information to attempt the ILS XXL back into ZZZ. I attempted to fly the approach with out the autopilot because the autopilot would kick off when joining the ILS. Once we got down to 500ft I became in stabilized and initiated a go around. After the go around we decided to try and re engage the autopilot once established on the ILS. We flew the autopilot down to Minimums and I disconnected it at 110ft; landed and taxied us to our gate.Cause:EFIS COMP MON due to failing AHRS system.
I was flying from ZZZ1 TO ZZZ. When we got an EFIS (Electronic Flight Instrument System) COMP (Comparator) MON (Monitor). We went through the QRH and it seemed like it was my side. We fixed the heading on my side and it went away. While coming into ZZZ my flight director and pitch were not matching up. Told the captain it didn't look right on my side. His looked right so he took the controls. When turning onto final his PFD (Primary Flight Display) screen turned on and off and the plane turned to the left. ATC saw the turn and cancelled our approach. They told us to turn 330 and then 300. Captain thought he was on 300. We were told multiple times to turn and correct our alt. Captain [requested priority handling] at that time. That's when I looked at the compass and noticed we were not on heading. I told Cap to fly standby compass. Once we got on the correct heading we ran the AHRS failure because captains side got a red rol (Roll) indication. Ran the QRH and fixed the rol. We confirmed with ATC the heading we were flying and told them we were ready for the approach.The clouds were down to min with 1/2 vis. At about four hundred feet the captain got off course one dot and he called a go around. He stated he got disoriented. ATC vectored us around for another approach. Once on final we turned on autopilot and Cap landed no problems.Cause: AHRS failure.
More incidents for this aircraft family
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.
Loading the flight search…
Pick an aircraft model — Boeing 737, Airbus A320, A380, Boeing 787 Dreamliner and more — enter your origin airport, and FlightFinder shows every route that plane flies from there with live fares.
We support Boeing 737/747/757/767/777/787, the full Airbus A220/A319/A320/A321/A330/A340/A350/A380 family, Embraer E170/E175/E190/E195, Bombardier CRJ and Dash 8, and the ATR 42/72 turboprops.
Search and schedules are free. Pro ($4.99/month, $39/year, or $99 one-time lifetime) unlocks the enriched flight card — on-time stats, CO₂ per passenger, amenities, live gate & weather — plus My Trips with push alerts.
Live schedules come from Amadeus, AeroDataBox and Travelpayouts. Observed routes (which aircraft actually flew a given city pair) are crowdsourced from adsb.lol ADS-B data under the Open Database License.