Flight crew experienced altitude excursion and altitude overshoot. Flight crew states caused by auto...

Attributes
ACN	169914
Time
Date	199102
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mol
State Reference	VA
Altitude	msl bound lower : 27000 msl bound upper : 28500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 80 flight time total : 14000 flight time type : 50
ASRS Report	169914
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : instrument pilot : commercial
Experience	flight time last 90 days : 174 flight time total : 7334 flight time type : 51
ASRS Report	170079
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : regained aircraft control
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

FL270-280, 30 mi north mol VOR. While in cruise at FL270 aircraft started climb. FMA was noted to go from VNAV level to VNAV climb. Immediate action was taken to stop climb and descent back to FL370. Maximum altitude excursion was 400' to FL274. ATC was notified of excursion. No traffic conflict resulted. Within approximately 1 min ATC gave clearance to climb to FL280. Climb was initiated of FMS. Aircraft did not level at FL280. FMA had going from VNAV capture to VNAV climb. Immediate action was taken to descend to FL280. Maximum altitude excursion was +500' to FL285. No traffic conflict resulted.

Original NASA ASRS Text

Title: FLT CREW EXPERIENCED ALT EXCURSION AND ALT OVERSHOOT. FLT CREW STATES CAUSED BY AUTOPLT MALFUNCTION.

Narrative: FL270-280, 30 MI N MOL VOR. WHILE IN CRUISE AT FL270 ACFT STARTED CLB. FMA WAS NOTED TO GO FROM VNAV LEVEL TO VNAV CLB. IMMEDIATE ACTION WAS TAKEN TO STOP CLB AND DSNT BACK TO FL370. MAX ALT EXCURSION WAS 400' TO FL274. ATC WAS NOTIFIED OF EXCURSION. NO TFC CONFLICT RESULTED. WITHIN APPROX 1 MIN ATC GAVE CLRNC TO CLB TO FL280. CLB WAS INITIATED OF FMS. ACFT DID NOT LEVEL AT FL280. FMA HAD GOING FROM VNAV CAPTURE TO VNAV CLB. IMMEDIATE ACTION WAS TAKEN TO DSND TO FL280. MAX ALT EXCURSION WAS +500' TO FL285. NO TFC CONFLICT RESULTED.

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.

Flight crew experienced altitude excursion and altitude overshoot. Flight crew states caused by autoplt malfunction.