Narrative:

During our third hold going into ZZZ; we had just told ATC that we would be diverting in a few mins due to fuel supply. Shortly after we had several yellow cas messages related to bleed misconfign; hydraulic pumps 1B and 2B. I looked up and the plane was descending about 400 ft below our assigned altitude; speed rasters were all red. It was very difficult to comprehend what was happening. Considering the hydraulic messages; the sudden autoplt descent (and subsequent climb); and we were in a stacked holding pattern; I quickly decided to declare an emergency; and announced we were having hydraulic issues and difficulty maintaining altitude. We requested immediate vectors to ZZZ to land. We regained altitude control; messages came and went. I (check airman giving IOE to a new first officer) assumed the controls; and asked the first officer to review only the QRH procedure for hydraulic pump 1B. The checklist essentially said to turn on the B pump. So although we did not have the yellow hydraulic cas at that moment; we decided to turn hydraulic 1B; 2B; 3B on. The flight attendant and passenger were briefed. Due to our low fuel situation; we expedited the approach rather than troubleshooting further. With the pumps on; things seemed to be ok. Flaps came out as usual (although flaps degrade white cas). Gear came down. Everything fine. On the ILS into ZZZ we were receiving erratic GS indications. At the FAF we quickly decided to continue as a localizer only approach; and made appropriate adjustments. Landed safely. Canceled emergency. The odd thing -- we still don't know what happened to the plane. If I had to guess; maybe a static buildup disturbed one of the computers. And either uncommanded extension of flaps; or the computer was confused and thought flaps were out. This would explain red speed raster; bleed misconfign; hydraulic B pumps trying to turn on; loss of altitude because flaps came out or automatic trim adjustment; brake temperatures being displayed. Who knows. I am curious though to see what maintenance had to say. Callback conversation with reporter revealed the following information: the reporter stated that maintenance could find no fault codes and that the aircraft was eventually released for flight with no maintenance action. The incident has not been repeated in the weeks since release. A faulty flap position indication is still the most plausible explanation for all of the warnings that occurred but why it occurred is unknown.

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Original NASA ASRS Text

Title: CRJ200 CAPT REPORTS OVERSPEED WARNING ALONG WITH CAS MESSAGES FOR BLEED MISCONFIGURATION AND HYDRAULIC PUMPS 1B AND 2B WHILE HOLDING.

Narrative: DURING OUR THIRD HOLD GOING INTO ZZZ; WE HAD JUST TOLD ATC THAT WE WOULD BE DIVERTING IN A FEW MINS DUE TO FUEL SUPPLY. SHORTLY AFTER WE HAD SEVERAL YELLOW CAS MESSAGES RELATED TO BLEED MISCONFIGN; HYD PUMPS 1B AND 2B. I LOOKED UP AND THE PLANE WAS DSNDING ABOUT 400 FT BELOW OUR ASSIGNED ALT; SPD RASTERS WERE ALL RED. IT WAS VERY DIFFICULT TO COMPREHEND WHAT WAS HAPPENING. CONSIDERING THE HYD MESSAGES; THE SUDDEN AUTOPLT DSCNT (AND SUBSEQUENT CLB); AND WE WERE IN A STACKED HOLDING PATTERN; I QUICKLY DECIDED TO DECLARE AN EMER; AND ANNOUNCED WE WERE HAVING HYD ISSUES AND DIFFICULTY MAINTAINING ALT. WE REQUESTED IMMEDIATE VECTORS TO ZZZ TO LAND. WE REGAINED ALT CTL; MESSAGES CAME AND WENT. I (CHK AIRMAN GIVING IOE TO A NEW FO) ASSUMED THE CTLS; AND ASKED THE FO TO REVIEW ONLY THE QRH PROC FOR HYD PUMP 1B. THE CHKLIST ESSENTIALLY SAID TO TURN ON THE B PUMP. SO ALTHOUGH WE DID NOT HAVE THE YELLOW HYD CAS AT THAT MOMENT; WE DECIDED TO TURN HYD 1B; 2B; 3B ON. THE FLT ATTENDANT AND PAX WERE BRIEFED. DUE TO OUR LOW FUEL SITUATION; WE EXPEDITED THE APCH RATHER THAN TROUBLESHOOTING FURTHER. WITH THE PUMPS ON; THINGS SEEMED TO BE OK. FLAPS CAME OUT AS USUAL (ALTHOUGH FLAPS DEGRADE WHITE CAS). GEAR CAME DOWN. EVERYTHING FINE. ON THE ILS INTO ZZZ WE WERE RECEIVING ERRATIC GS INDICATIONS. AT THE FAF WE QUICKLY DECIDED TO CONTINUE AS A LOC ONLY APCH; AND MADE APPROPRIATE ADJUSTMENTS. LANDED SAFELY. CANCELED EMER. THE ODD THING -- WE STILL DON'T KNOW WHAT HAPPENED TO THE PLANE. IF I HAD TO GUESS; MAYBE A STATIC BUILDUP DISTURBED ONE OF THE COMPUTERS. AND EITHER UNCOMMANDED EXTENSION OF FLAPS; OR THE COMPUTER WAS CONFUSED AND THOUGHT FLAPS WERE OUT. THIS WOULD EXPLAIN RED SPD RASTER; BLEED MISCONFIGN; HYD B PUMPS TRYING TO TURN ON; LOSS OF ALT BECAUSE FLAPS CAME OUT OR AUTO TRIM ADJUSTMENT; BRAKE TEMPS BEING DISPLAYED. WHO KNOWS. I AM CURIOUS THOUGH TO SEE WHAT MAINT HAD TO SAY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE REPORTER STATED THAT MAINTENANCE COULD FIND NO FAULT CODES AND THAT THE ACFT WAS EVENTUALLY RELEASED FOR FLIGHT WITH NO MAINTENANCE ACTION. THE INCIDENT HAS NOT BEEN REPEATED IN THE WEEKS SINCE RELEASE. A FAULTY FLAP POSITION INDICATION IS STILL THE MOST PLAUSIBLE EXPLANATION FOR ALL OF THE WARNINGS THAT OCCURRED BUT WHY IT OCCURRED IS UNKNOWN.

Data retrieved from NASA's ASRS site as of May 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.