Aircraft equipment problem --jammed stabilizer.

Attributes
ACN	314399
Time
Date	199508
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : cdg
State Reference	FO
Altitude	agl bound lower : 0 agl bound upper : 10000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : cdg
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach descent other landing other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10500 flight time type : 9000
ASRS Report	314399
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Air Traffic Incident	Pilot Deviation

Narrative:

While on descent into cdg the stabilizer jammed at 0 degrees, cruise setting. All checklists were completed, all methods of moving the stabilizer, main and cruise electric and manual would not budge the stabilizer. The pulling of the brake release with application of stabilizer trim had no effect. An emergency was declared, equipment requested and a landing accomplished. This aircraft has a history of stabilizer problems and a similar problem was described in feb/xx/95 with a NASA report. The problem, as per maintenance, is the auxiliary brake, a new jack screw assembly was installed. Callback conversation with reporter revealed the following information: aircraft had previous write-ups on the jammed stabilizer and the reporter had even sent an ASRS report about it previously. In the past instances the pilots were able to release the stabilizer brake, but not this time. There are 2 stabilizer brakes, one can be released with the stabilizer brake release knob and the other, which is on the jack screw assembly operates differently. That brake is applied when a runaway stabilizer develops and the centrifugal sensing mechanism applies the brake. Apparently, the centrifugal sensing malfunctioned and the jack screw assembly brake was applied and could not be released by the flight crew. Since the malfunction occurred in cruise, the stabilizer jammed at 0 degrees. The stabilizer setting normally is approximately 5 degrees nose up for takeoff and landing. Consequently, the nose was very nose heavy for approach and landing and, in fact, in order to aid the captain in holding the nose up, the first officer had his arms around the yoke and pulling to help keep it up. The captain also carried extra airspeed on the approach to also help with the nose position. On approach to charles de gaul airport in paris, the reporter declared an emergency and on approach at 1000 ft the tower cleared an aircraft onto the runway for takeoff. When the reporter notified the tower that they were an emergency, the tower said, 'be advised windshear reported.'

Original NASA ASRS Text

Title: ACFT EQUIP PROB --JAMMED STABILIZER.

Narrative: WHILE ON DSCNT INTO CDG THE STABILIZER JAMMED AT 0 DEGS, CRUISE SETTING. ALL CHKLISTS WERE COMPLETED, ALL METHODS OF MOVING THE STABILIZER, MAIN AND CRUISE ELECTRIC AND MANUAL WOULD NOT BUDGE THE STABILIZER. THE PULLING OF THE BRAKE RELEASE WITH APPLICATION OF STABILIZER TRIM HAD NO EFFECT. AN EMER WAS DECLARED, EQUIP REQUESTED AND A LNDG ACCOMPLISHED. THIS ACFT HAS A HISTORY OF STABILIZER PROBS AND A SIMILAR PROB WAS DESCRIBED IN FEB/XX/95 WITH A NASA RPT. THE PROB, AS PER MAINT, IS THE AUX BRAKE, A NEW JACK SCREW ASSEMBLY WAS INSTALLED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: ACFT HAD PREVIOUS WRITE-UPS ON THE JAMMED STABILIZER AND THE RPTR HAD EVEN SENT AN ASRS RPT ABOUT IT PREVIOUSLY. IN THE PAST INSTANCES THE PLTS WERE ABLE TO RELEASE THE STABILIZER BRAKE, BUT NOT THIS TIME. THERE ARE 2 STABILIZER BRAKES, ONE CAN BE RELEASED WITH THE STABILIZER BRAKE RELEASE KNOB AND THE OTHER, WHICH IS ON THE JACK SCREW ASSEMBLY OPERATES DIFFERENTLY. THAT BRAKE IS APPLIED WHEN A RUNAWAY STABILIZER DEVELOPS AND THE CENTRIFUGAL SENSING MECHANISM APPLIES THE BRAKE. APPARENTLY, THE CENTRIFUGAL SENSING MALFUNCTIONED AND THE JACK SCREW ASSEMBLY BRAKE WAS APPLIED AND COULD NOT BE RELEASED BY THE FLC. SINCE THE MALFUNCTION OCCURRED IN CRUISE, THE STABILIZER JAMMED AT 0 DEGS. THE STABILIZER SETTING NORMALLY IS APPROX 5 DEGS NOSE UP FOR TKOF AND LNDG. CONSEQUENTLY, THE NOSE WAS VERY NOSE HVY FOR APCH AND LNDG AND, IN FACT, IN ORDER TO AID THE CAPT IN HOLDING THE NOSE UP, THE FO HAD HIS ARMS AROUND THE YOKE AND PULLING TO HELP KEEP IT UP. THE CAPT ALSO CARRIED EXTRA AIRSPD ON THE APCH TO ALSO HELP WITH THE NOSE POS. ON APCH TO CHARLES DE GAUL ARPT IN PARIS, THE RPTR DECLARED AN EMER AND ON APCH AT 1000 FT THE TWR CLRED AN ACFT ONTO THE RWY FOR TKOF. WHEN THE RPTR NOTIFIED THE TWR THAT THEY WERE AN EMER, THE TWR SAID, 'BE ADVISED WINDSHEAR RPTED.'

Data retrieved from NASA's ASRS site as of July 2007 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.