Temporary loss of aircraft control when a B747-100 flight has an en route problem with #2 autoplt an...

Attributes
ACN	537733
Time
Date	200202
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	intersection : pugal
State Reference	FO
Altitude	msl bound lower : 33000 msl bound upper : 34100
Environment
Light	Night
Aircraft 1
Controlling Facilities	artcc : zoa.artcc
Operator	common carrier : air carrier
Make Model Name	B747-100
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Route In Use	enroute airway : a590.airway
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
ASRS Report	537733
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical airspace violation : exit altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : overrode automation flight crew : regained aircraft control flight crew : returned to assigned altitude flight crew : returned to intended or assigned course other
Consequence	other other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

This incident occurred with a B747-100 leased to air carrier X on a military contract flight between rodn-panc-ksuu on the rodn-panc segment, approximately 13 mins northeast of pugal on nopac airway 590. The aircraft was operating at FL330, mach .848 in smooth conditions in the clear with a 50 KT tailwind (approximately) autoplt 'B' engaged in GPS mode. The first officer was PF. The captain was at the end of the process of annotating a procedural 10 min navigation plot. The aircraft entered (smoothly) a 15 degree left turn (uncommanded) off course and track with a commensurate rate of turn. The first officer announced the problem immediately to the captain. The off course turn was displayed in all 3 GPS CDU's with appropriate course indicator and track error pointed deflections. All compass/HSI/roll indications reflected reasonable indications to the aircraft's turn. The autoplt and aircraft failed to respond to a 'direct to entry' in the 'flying' GPS (#2). The captain suggested and selected heading mode on the autoflt management module whereas the bank now rapidly increased toward 35 degrees of bank towards the left (away from the heading bug) resulting in an increased rate of turn and pitch. The captain acquired control and disengaged the autoplt at approximately 30 degrees left bank and 9 degrees nose-up pitch. The aircraft was rolled wings level and found to be considerably out of trim, nose up, resulting in an initial 3000 FPM climb that was arrested finally at FL340-FL341, 1000-1100 ft above cruise FL330. An immediate manual return to assigned level and track was initiated by the captain. Once the aircraft was manually established back on track and level, autoplt 'a' was engaged, GPS ode was selected, and control returned to the first officer. The flight continued to panc and was uneventful, and the facility autoplt's system was logged and a captain's irregularity report was filed. Elapsed time approximately 6-7 mins, off course 60-70 degrees north of track, 19 NM, maximum altitude deviation +1000 ft.

Original NASA ASRS Text

Title: TEMPORARY LOSS OF ACFT CTL WHEN A B747-100 FLT HAS AN ENRTE PROB WITH #2 AUTOPLT AND ENDS UP 19 NM N OF COURSE, 1000 FT TOO HIGH. THIS WAS A 6-7 MIN ENCOUNTER WITH AN UNEXPECTED TURN OFF AIRWAY A590 ON FREQ WITH ZOA, CA.

Narrative: THIS INCIDENT OCCURRED WITH A B747-100 LEASED TO ACR X ON A MIL CONTRACT FLT BTWN RODN-PANC-KSUU ON THE RODN-PANC SEGMENT, APPROX 13 MINS NE OF PUGAL ON NOPAC AIRWAY 590. THE ACFT WAS OPERATING AT FL330, MACH .848 IN SMOOTH CONDITIONS IN THE CLR WITH A 50 KT TAILWIND (APPROX) AUTOPLT 'B' ENGAGED IN GPS MODE. THE FO WAS PF. THE CAPT WAS AT THE END OF THE PROCESS OF ANNOTATING A PROCEDURAL 10 MIN NAV PLOT. THE ACFT ENTERED (SMOOTHLY) A 15 DEG L TURN (UNCOMMANDED) OFF COURSE AND TRACK WITH A COMMENSURATE RATE OF TURN. THE FO ANNOUNCED THE PROB IMMEDIATELY TO THE CAPT. THE OFF COURSE TURN WAS DISPLAYED IN ALL 3 GPS CDU'S WITH APPROPRIATE COURSE INDICATOR AND TRACK ERROR POINTED DEFLECTIONS. ALL COMPASS/HSI/ROLL INDICATIONS REFLECTED REASONABLE INDICATIONS TO THE ACFT'S TURN. THE AUTOPLT AND ACFT FAILED TO RESPOND TO A 'DIRECT TO ENTRY' IN THE 'FLYING' GPS (#2). THE CAPT SUGGESTED AND SELECTED HDG MODE ON THE AUTOFLT MGMNT MODULE WHEREAS THE BANK NOW RAPIDLY INCREASED TOWARD 35 DEGS OF BANK TOWARDS THE L (AWAY FROM THE HDG BUG) RESULTING IN AN INCREASED RATE OF TURN AND PITCH. THE CAPT ACQUIRED CTL AND DISENGAGED THE AUTOPLT AT APPROX 30 DEGS L BANK AND 9 DEGS NOSE-UP PITCH. THE ACFT WAS ROLLED WINGS LEVEL AND FOUND TO BE CONSIDERABLY OUT OF TRIM, NOSE UP, RESULTING IN AN INITIAL 3000 FPM CLB THAT WAS ARRESTED FINALLY AT FL340-FL341, 1000-1100 FT ABOVE CRUISE FL330. AN IMMEDIATE MANUAL RETURN TO ASSIGNED LEVEL AND TRACK WAS INITIATED BY THE CAPT. ONCE THE ACFT WAS MANUALLY ESTABLISHED BACK ON TRACK AND LEVEL, AUTOPLT 'A' WAS ENGAGED, GPS ODE WAS SELECTED, AND CTL RETURNED TO THE FO. THE FLT CONTINUED TO PANC AND WAS UNEVENTFUL, AND THE FACILITY AUTOPLT'S SYS WAS LOGGED AND A CAPT'S IRREGULARITY RPT WAS FILED. ELAPSED TIME APPROX 6-7 MINS, OFF COURSE 60-70 DEGS N OF TRACK, 19 NM, MAX ALT DEV +1000 FT.

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.

Temporary loss of aircraft control when a B747-100 flight has an en route problem with #2 autoplt and ends up 19 NM north of course, 1000 ft too high. This was a 6-7 min encounter with an unexpected turn off airway A590 on frequency with ZOA, ca.