Medium large transport descends below assigned altitude.

Attributes
ACN	253985
Time
Date	199310
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : okc
State Reference	OK
Altitude	msl bound lower : 26100 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 220 flight time total : 9000 flight time type : 195
ASRS Report	253985
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

First officer was copying destination ATIS while captain (who was making a PA) descended through level off ht of FL270 to approximately FL261 before correcting back to cleared altitude. Both pilots were aware of altitude deviation descending through approximately FL268 when the effort was made to correct back to FL270. ZKC asked us to check altitude cleared to at approximately FL265 (good job by them). Corrective action: change my habit pattern, have the PNF make PA's.

Original NASA ASRS Text

Title: MLG DSNDS BELOW ASSIGNED ALT.

Narrative: FO WAS COPYING DEST ATIS WHILE CAPT (WHO WAS MAKING A PA) DSNDED THROUGH LEVEL OFF HT OF FL270 TO APPROX FL261 BEFORE CORRECTING BACK TO CLRED ALT. BOTH PLTS WERE AWARE OF ALTDEV DSNDING THROUGH APPROX FL268 WHEN THE EFFORT WAS MADE TO CORRECT BACK TO FL270. ZKC ASKED US TO CHK ALT CLRED TO AT APPROX FL265 (GOOD JOB BY THEM). CORRECTIVE ACTION: CHANGE MY HABIT PATTERN, HAVE THE PNF MAKE PA'S.

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.