Altitude deviation atx X unauthorized descent below assigned altitude during descent.

Attributes
ACN	293776
Time
Date	199501
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : act
State Reference	TX
Altitude	msl bound lower : 5500 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	common carrier : air taxi
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	descent other
Route In Use	enroute : direct enroute airway : grk
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 250 flight time total : 3500 flight time type : 900
ASRS Report	293776
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 5000 flight time type : 1000
ASRS Report	294063
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Atx X descent from 8000 ft to 6000 ft into killeen, tx, gray approach called converging traffic climbing through 6000 ft. Neither the captain nor myself had a visual on the traffic and I was worried about the traffic ending up at the same altitude as us. I continued the descent to 5500 ft when the captain reminded me of the 6000 ft clearance. I climbed back to 6000 ft with no further incident. I believe the altitude deviation was caused by my distraction in looking for the traffic. The only remedy I can think of would be an altitude alerter as well as better attention on my part. Supplemental information from acn 294063: on our descent into ile, and approximately 400 ft before our leveloff altitude, gray approach called conflicting traffic very close to us and converging on our flight path. Both my attention and the PF's attention were diverted to find the traffic. While we were looking for traffic we descended approximately 500 ft below our assigned altitude and then immediately recovered back to assigned altitude. If we had an altitude alerter and the PF had remained alert to flying the plane, this probably would not have happened.

Original NASA ASRS Text

Title: ALTDEV ATX X UNAUTH DSCNT BELOW ASSIGNED ALT DURING DSCNT.

Narrative: ATX X DSCNT FROM 8000 FT TO 6000 FT INTO KILLEEN, TX, GRAY APCH CALLED CONVERGING TFC CLBING THROUGH 6000 FT. NEITHER THE CAPT NOR MYSELF HAD A VISUAL ON THE TFC AND I WAS WORRIED ABOUT THE TFC ENDING UP AT THE SAME ALT AS US. I CONTINUED THE DSCNT TO 5500 FT WHEN THE CAPT REMINDED ME OF THE 6000 FT CLRNC. I CLBED BACK TO 6000 FT WITH NO FURTHER INCIDENT. I BELIEVE THE ALTDEV WAS CAUSED BY MY DISTR IN LOOKING FOR THE TFC. THE ONLY REMEDY I CAN THINK OF WOULD BE AN ALT ALERTER AS WELL AS BETTER ATTN ON MY PART. SUPPLEMENTAL INFO FROM ACN 294063: ON OUR DSCNT INTO ILE, AND APPROX 400 FT BEFORE OUR LEVELOFF ALT, GRAY APCH CALLED CONFLICTING TFC VERY CLOSE TO US AND CONVERGING ON OUR FLT PATH. BOTH MY ATTN AND THE PF'S ATTN WERE DIVERTED TO FIND THE TFC. WHILE WE WERE LOOKING FOR TFC WE DSNDED APPROX 500 FT BELOW OUR ASSIGNED ALT AND THEN IMMEDIATELY RECOVERED BACK TO ASSIGNED ALT. IF WE HAD AN ALT ALERTER AND THE PF HAD REMAINED ALERT TO FLYING THE PLANE, THIS PROBABLY WOULD NOT HAVE HAPPENED.

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.