Altitude heading deviation.

Attributes
ACN	158277
Time
Date	199009
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : pmm
State Reference	MI
Altitude	msl bound lower : 20000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument pilot : flight engineer
Experience	flight time last 90 days : 170 flight time total : 7800 flight time type : 500
ASRS Report	158277
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 170 flight time total : 5500 flight time type : 500
ASRS Report	158273
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Pilot Deviation

Narrative:

Airlines flight xxz while cruising at FL310, we copied a clearance to 'descend and maintain FL200, turn left to heading 030 degrees to intercept V84 to pullman.' shortly after beginning descent center asked if we were maintaining FL310. We advised we were descending per our clearance (which we had read back). We were reclred to FL310 and give a 70 degree turn away from traffic. The captain called on the phone and found that no deviations were being written up. Center was investigating a possible bleed through problem with their equipment. There was also another air carrier flight yz on the frequency.

Original NASA ASRS Text

Title: ALT HEADING DEVIATION.

Narrative: AIRLINES FLT XXZ WHILE CRUISING AT FL310, WE COPIED A CLRNC TO 'DSND AND MAINTAIN FL200, TURN LEFT TO HDG 030 DEGS TO INTERCEPT V84 TO PULLMAN.' SHORTLY AFTER BEGINNING DSNT CENTER ASKED IF WE WERE MAINTAINING FL310. WE ADVISED WE WERE DSNDING PER OUR CLRNC (WHICH WE HAD READ BACK). WE WERE RECLRED TO FL310 AND GIVE A 70 DEG TURN AWAY FROM TFC. THE CAPT CALLED ON THE PHONE AND FOUND THAT NO DEVIATIONS WERE BEING WRITTEN UP. CENTER WAS INVESTIGATING A POSSIBLE BLEED THROUGH PROB WITH THEIR EQUIP. THERE WAS ALSO ANOTHER ACR FLT YZ ON THE FREQ.

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.