Altitude deviation. Excursion from assigned. Unable callback.

Attributes
ACN	142647
Time
Date	199004
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : ilm
State Reference	NC
Altitude	msl bound lower : 15000 msl bound upper : 22000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other cruise other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 90 flight time total : 9800 flight time type : 1000
ASRS Report	142647
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem flight crew : returned to intended course or assigned course flight crew : regained aircraft control flight crew : declared emergency
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

During a maintenance check flight on 4/mon/90, aircraft XXXX, a widebody transport was operating in the block altitude FL200-220. ATC was informed the flight was operating as a maintenance check flight when the block altitude was requested. The aircraft was configured for a clean approach to stick shaker. With the onset of stick shaker, manual procedures were followed with application of full thrust available (mct). Engines #2 and #3 accelerated normally to selected thrust, while #1 did not accelerate. This caused the aircraft to yaw to the left. I decreased pitch while attempting to control the yaw. The #3 throttle was retarded and the aircraft was returned to normal flight. During this time, the crew informed ATC that they would be unable to maintain the assigned block altitude. ATC advised that there was no traffic below the aircraft and to report back in the block. A total of approximately 5000' was lost during the recovery with no aircraft limitations being exceeded. The aircraft was returned to the block altitude and completed the flight west/O further incident. The engine was reported to maintenance and repaired prior to the next flight.

Original NASA ASRS Text

Title: ALT DEVIATION. EXCURSION FROM ASSIGNED. UNABLE CALLBACK.

Narrative: DURING A MAINT CHK FLT ON 4/MON/90, ACFT XXXX, A WDB WAS OPERATING IN THE BLOCK ALT FL200-220. ATC WAS INFORMED THE FLT WAS OPERATING AS A MAINT CHK FLT WHEN THE BLOCK ALT WAS REQUESTED. THE ACFT WAS CONFIGURED FOR A CLEAN APCH TO STICK SHAKER. WITH THE ONSET OF STICK SHAKER, MANUAL PROCS WERE FOLLOWED WITH APPLICATION OF FULL THRUST AVAILABLE (MCT). ENGS #2 AND #3 ACCELERATED NORMALLY TO SELECTED THRUST, WHILE #1 DID NOT ACCELERATE. THIS CAUSED THE ACFT TO YAW TO THE L. I DECREASED PITCH WHILE ATTEMPTING TO CTL THE YAW. THE #3 THROTTLE WAS RETARDED AND THE ACFT WAS RETURNED TO NORMAL FLT. DURING THIS TIME, THE CREW INFORMED ATC THAT THEY WOULD BE UNABLE TO MAINTAIN THE ASSIGNED BLOCK ALT. ATC ADVISED THAT THERE WAS NO TFC BELOW THE ACFT AND TO RPT BACK IN THE BLOCK. A TOTAL OF APPROX 5000' WAS LOST DURING THE RECOVERY WITH NO ACFT LIMITATIONS BEING EXCEEDED. THE ACFT WAS RETURNED TO THE BLOCK ALT AND COMPLETED THE FLT W/O FURTHER INCIDENT. THE ENG WAS RPTED TO MAINT AND REPAIRED PRIOR TO THE NEXT FLT.

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.