Air carrier medium large transport altitude deviation excursion from clearance altitude in response ...

Attributes
ACN	180555
Time
Date	199105
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : atl
State Reference	GA
Altitude	msl bound lower : 11000 msl bound upper : 11500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : atl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
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 : 165 flight time total : 10000 flight time type : 45
ASRS Report	180555
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	vertical : 1500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Passing through approximately 11500' on arrival descent to 11000', we were requested to slow to 210 KTS. Controller was not satisfied with our rate of slowdown, so a vector from heading approximately 270 degree to 360 was given. At about 350 degree heading, a TCAS conflict alert came on and first officer climbed aircraft back up to 500'. I alerted approach to this fact, and they reminded us of other traffic. This avoidance may have conflicted us with traffic. Our TCAS evidently alerted on an aircraft climbing to 10000'. Our clearance was 11000', but TCAS did not know other aircraft was going to level.

Original NASA ASRS Text

Title: ACR MLG ALT DEVIATION EXCURSION FROM CLRNC ALT IN RESPONSE TO TCAS TA.

Narrative: PASSING THROUGH APPROX 11500' ON ARR DSNT TO 11000', WE WERE REQUESTED TO SLOW TO 210 KTS. CTLR WAS NOT SATISFIED WITH OUR RATE OF SLOWDOWN, SO A VECTOR FROM HDG APPROX 270 DEG TO 360 WAS GIVEN. AT ABOUT 350 DEG HDG, A TCAS CONFLICT ALERT CAME ON AND F/O CLBED ACFT BACK UP TO 500'. I ALERTED APCH TO THIS FACT, AND THEY REMINDED US OF OTHER TFC. THIS AVOIDANCE MAY HAVE CONFLICTED US WITH TFC. OUR TCAS EVIDENTLY ALERTED ON AN ACFT CLBING TO 10000'. OUR CLRNC WAS 11000', BUT TCAS DID NOT KNOW OTHER ACFT WAS GOING TO LEVEL.

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.

Air carrier medium large transport altitude deviation excursion from clearance altitude in response to TCAS TA.