What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23)On October 20, 2008, at approximately 0823 eastern time, a Bombardier, CL-600-2B19, conducted under 14CFR part 121, flying from the philadelphia international airport (kphl) to the detroit metropolitan wayne county airport (kdtw), while at cruise the aicraft indicated the flaps were coming down. Shortly there after the aircraft began to pitch up and down. The crew declared an emergency and the aircraft was diverted to Pittsburgh International Airport (kpit) and landed on runway 28R without further incident. The aircraft rescue fire fighting (ARFF) units had responded yet were not utilized. There were no injuries to the crew or passengers. The captain of the aircraft made the following statement: "upon reaching FL280, (cruising alt.) We received indications that would normally appear when we configure for landing. These indications were brake temp, gear icons, flap position indicator, speed raster coming down to 210 KTS. During these indications the aircraft with autopilot on was starting to porpoise up and down +/-50-100'. The "flaps degraded" status msg appeared as well. We notified ATC immediataely, about having some problems, and issues with holding altitude and would be diverting in a few minutes. F/o privacy data omitted, and I agreed that pittsburg would be the closest airport to divert to. After talking to mx, and dispatch they concurred that pit it was. We didn't declare an emergency because these indications had no longer came up, and everything seemed to be normal. During these alt. Fluctuations, I had asked the f/a to go back and watch to see if the flaps were moving at all. It was confirmed after a couple of minutes that the flaps didn't appear to be moving when these indications came up. Before we started the diversion to pit the aircraft nosed over briefly with about a 500' loss. The aircraft recovered almost instantly back to FL280. That was the last occurrence with these indications as we were going into pit. The arrival, and configuration into landing, and landing went uneventful. The gate agent/supervisor, manager, and ATC were very helpful upon this unscheduled arrival. Many thanks to them!!" The aircraft's skew detection unit (sdu) was bypassed and the aircraft was moved to a maintenance facility via a special flight permit. The skew detection unit and the left flap position transmitter unit (fptu) were removed and replaced. Additionally the digital flight data recorder (dfdr) was downloaded and analyzed. Afterwards the aircraft was returned to service. The flight crew's actions or lack of actions did not contribute to this incident.
As the FAA filed it
(-23)ON OCTOBER 20, 2008, AT APPROXIMATELY 0823 EASTERN TIME, A BOMBARDIER, CL-600-2B19, CONDUCTED UNDER 14CFR PART 121, FLYING FROM THE PHILADELPHIA INTERNATIONAL AIRPORT (KPHL) TO THE DETROIT METROPOLITAN WAYNE COUNTY AIRPORT (KDTW), WHILE AT CRUISE THE AICRAFT INDICATED THE FLAPS WERE COMING DOWN. SHORTLY THERE AFTER THE AIRCRAFT BEGAN TO PITCH UP AND DOWN. THE CREW DECLARED AN EMERGENCY AND THE AIRCRAFT WAS DIVERTED TO PITTSBURGH INTERNATIONAL AIRPORT (KPIT) AND LANDED ON RUNWAY 28R WITHOUT FURTHER INCIDENT. THE AIRCRAFT RESCUE FIRE FIGHTING (ARFF) UNITS HAD RESPONDED YET WERE NOT UTILIZED. THERE WERE NO INJURIES TO THE CREW OR PASSENGERS. THE CAPTAIN OF THE AIRCRAFT MADE THE FOLLOWING STATEMENT: "UPON REACHING FL280, (CRUISING ALT.) WE RECEIVED INDICATIONS THAT WOULD NORMALLY APPEAR WHEN WE CONFIGURE FOR LANDING. THESE INDICATIONS WERE BRAKE TEMP, GEAR ICONS, FLAP POSITION INDICATOR, SPEED RASTER COMING DOWN TO 210 KTS. DURING THESE INDICATIONS THE AIRCRAFT WITH AUTOPILOT ON WAS STARTING TO PORPOISE UP AND DOWN +/-50-100'. THE "FLAPS DEGRADED" STATUS MSG APPEARED AS WELL. WE NOTIFIED ATC IMMEDIATAELY, ABOUT HAVING SOME PROBLEMS, AND ISSUES WITH HOLDING ALTITUDE AND WOULD BE DIVERTING IN A FEW MINUTES. F/O ^PRIVACY DATA OMITTED^, AND I AGREED THAT PITTSBURG WOULD BE THE CLOSEST AIRPORT TO DIVERT TO. AFTER TALKING TO MX, AND DISPATCH THEY CONCURRED THAT PIT IT WAS. WE DIDN'T DECLARE AN EMERGENCY BECAUSE THESE INDICATIONS HAD NO LONGER CAME UP, AND EVERYTHING SEEMED TO BE NORMAL. DURING THESE ALT. FLUCTUATIONS, I HAD ASKED THE F/A TO GO BACK AND WATCH TO SEE IF THE FLAPS WERE MOVING AT ALL. IT WAS CONFIRMED AFTER A COUPLE OF MINUTES THAT THE FLAPS DIDN'T APPEAR TO BE MOVING WHEN THESE INDICATIONS CAME UP. BEFORE WE STARTED THE DIVERSION TO PIT THE AIRCRAFT NOSED OVER BRIEFLY WITH ABOUT A 500' LOSS. THE AIRCRAFT RECOVERED ALMOST INSTANTLY BACK TO FL280. THAT WAS THE LAST OCCURRENCE WITH THESE INDICATIONS AS WE WERE GOING INTO PIT. THE ARRIVAL, AND CONFIGURATION INTO LANDING, AND LANDING WENT UNEVENTFUL. THE GATE AGENT/SUPERVISOR, MANAGER, AND ATC WERE VERY HELPFUL UPON THIS UNSCHEDULED ARRIVAL. MANY THANKS TO THEM!!" THE AIRCRAFT'S SKEW DETECTION UNIT (SDU) WAS BYPASSED AND THE AIRCRAFT WAS MOVED TO A MAINTENANCE FACILITY VIA A SPECIAL FLIGHT PERMIT. THE SKEW DETECTION UNIT AND THE LEFT FLAP POSITION TRANSMITTER UNIT (FPTU) WERE REMOVED AND REPLACED. ADDITIONALLY THE DIGITAL FLIGHT DATA RECORDER (DFDR) WAS DOWNLOADED AND ANALYZED. AFTERWARDS THE AIRCRAFT WAS RETURNED TO SERVICE. THE FLIGHT CREW'S ACTIONS OR LACK OF ACTIONS DID NOT CONTRIBUTE TO THIS INCIDENT.