2011-09 · NASA ASRS report 971280
SF340 flight crew experiences FMS failure shortly after departure; then a right recirculation fan fault en route. While attempting to navigate using the autopilot to track the VOR CDI; a course deviation occurs for unknown reasons.
While flying in cruise; the FMS failed and then we had a recirculation fan fail. As we were working with both of these; we were given a heading to intercept an airway. We were about 20 miles from BDR VOR and when I selected NAV mode after selecting the heading to intercept we had full scale deflection to the right and the airplane turned left. We were both busy trying to figure out what was going on with the airplane and we overflew a waypoint. ATC called and told us we had over flown the waypoint; then gave us a vector to the next waypoint. As far as we know there were no conflicts with other traffic. Nothing was close to us on TCAS.The FMS had been written up in the log and signed off as fixed. The recirculation fan had also been written up in the same book and signed off as fixed. This all happened in about the same area [where] SF340 crews are always getting false capture of the LOC for Runway 22. It was very busy with all this going on at one time. We could have asked for a heading until we had some of these things under control. The workload was very high at this time.
Shortly after takeoff; our FMS locked up and became unusable. We could not turn it off. We notified ATC of our issue and told them we are to navigate VOR to VOR. En route; we received a 'Right Recirc Fan' fault. While dealing with this and navigating; we got a false capture of some sort and overflew BDR. ATC then came on and gave us a heading of 260 to join up with V475. We went back to HDG mode and navigated that way. As far as we know there was no conflict with any other aircraft in the area.While dealing with 3 separate problems; FMS failure; recirculation fan; and the false capture the workload was pretty high at the time. Not being able to use the NAV function of the autopilot added to the problems. This all occurred during the decent phase of flight.
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.