Pilot deviation. - NASA ASRS

Attributes
ACN	288921
Time
Date	199411
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : stl
State Reference	MO
Altitude	msl bound lower : 24000 msl bound upper : 24000
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zkc
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 121
Flight Phase	cruise other descent other
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	other : unknown
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 17000 flight time type : 1500
ASRS Report	288921
Person 2
Function	flight crew : single pilot
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : clearance
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Miss Distance	vertical : 2500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Operating dfw to stl on nov/xx/94, we were holding due to thunderstorms in the area of the stl airport. While holding at 24000 ft, we believe we received a clearance to fly a 360 degree heading to intercept the stl 327 degree radial for the arrival, and to descend so as to cross the lorle intersection at 11000 ft. We read back the clearance and started our descent. After descending about 1500 ft, the TCASII gave us a TA. I saw on the TCASII that the aircraft was in our general flight path about 2000 ft below us. I immediately started a climb back to a higher altitude. Shortly thereafter, ATC advised us our assigned altitude was 24000 ft. We do not know who is at fault. The situation was that everybody was very busy due to the WX. We believe we were cleared to a lower altitude, we read back our clearance to do as we were instructed. In addition, we had an acm on board who is a check captain who also heard the clearance and thought we were correct. The TCASII was the reason the problem was discovered early.

Original NASA ASRS Text

Title: PLTDEV.

Narrative: OPERATING DFW TO STL ON NOV/XX/94, WE WERE HOLDING DUE TO TSTMS IN THE AREA OF THE STL ARPT. WHILE HOLDING AT 24000 FT, WE BELIEVE WE RECEIVED A CLRNC TO FLY A 360 DEG HDG TO INTERCEPT THE STL 327 DEG RADIAL FOR THE ARR, AND TO DSND SO AS TO CROSS THE LORLE INTXN AT 11000 FT. WE READ BACK THE CLRNC AND STARTED OUR DSCNT. AFTER DSNDING ABOUT 1500 FT, THE TCASII GAVE US A TA. I SAW ON THE TCASII THAT THE ACFT WAS IN OUR GENERAL FLT PATH ABOUT 2000 FT BELOW US. I IMMEDIATELY STARTED A CLB BACK TO A HIGHER ALT. SHORTLY THEREAFTER, ATC ADVISED US OUR ASSIGNED ALT WAS 24000 FT. WE DO NOT KNOW WHO IS AT FAULT. THE SIT WAS THAT EVERYBODY WAS VERY BUSY DUE TO THE WX. WE BELIEVE WE WERE CLRED TO A LOWER ALT, WE READ BACK OUR CLRNC TO DO AS WE WERE INSTRUCTED. IN ADDITION, WE HAD AN ACM ON BOARD WHO IS A CHK CAPT WHO ALSO HEARD THE CLRNC AND THOUGHT WE WERE CORRECT. THE TCASII WAS THE REASON THE PROB WAS DISCOVERED EARLY.

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.