Air carrier B757 aircraft in cruise and on autoplt. Aircraft descended 250 ft setting off altitude alert. Reporter first officer disconnected autoplt and returned to assigned altitude.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	377720
Time
Date	199708
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zlc
State Reference	UT
Altitude	msl bound lower : 34750 msl bound upper : 35000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zlc
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute airway : zlc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
ASRS Report	377720
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	377719
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While at cruise with center autoplt engaged, the altitude alert sounded as we descended about 250 ft below FL350. First officer, PF, disconnected the autoplt and hand flew back to altitude, then engaged right autoplt.

Original NASA ASRS Text

Title: ACR B757 ACFT IN CRUISE AND ON AUTOPLT. ACFT DSNDED 250 FT SETTING OFF ALT ALERT. RPTR FO DISCONNECTED AUTOPLT AND RETURNED TO ASSIGNED ALT.

Narrative: WHILE AT CRUISE WITH CTR AUTOPLT ENGAGED, THE ALT ALERT SOUNDED AS WE DSNDED ABOUT 250 FT BELOW FL350. FO, PF, DISCONNECTED THE AUTOPLT AND HAND FLEW BACK TO ALT, THEN ENGAGED R AUTOPLT.

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.