B737-700 crew had altitude overshoot in ZHU class a airspace.

Attributes
ACN	503890
Time
Date	200103
Day	Sun
Local Time Of Day	0601 To 1200
Place
State Reference	TX
Altitude	msl bound lower : 28000 msl bound upper : 28500
Environment
Flight Conditions	IMC
Light	Dawn
Aircraft 1
Controlling Facilities	artcc : zhu.artcc
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : vacating altitude descent : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 8000 flight time type : 5000
ASRS Report	503890
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : overshoot altitude deviation : excursion from assigned altitude non adherence : company policies non adherence : published procedure non adherence : far non adherence : clearance other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : returned to assigned altitude none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Climbing to FL280 on autoplt. The aircraft autoleveled at FL280. The autoplt was still in the altitude acquire mode when ATC gave us pilot's discretion back down to FL240. The first officer put FL240 in the altitude alert window with the autoplt still in the altitude acquire mode. The autoplt did not capture FL280 and overshot FL280 by 500 ft, before I noticed it and made a manual correction. No comment was made by ATC. We continued our descent normally.

Original NASA ASRS Text

Title: B737-700 CREW HAD ALT OVERSHOOT IN ZHU CLASS A AIRSPACE.

Narrative: CLBING TO FL280 ON AUTOPLT. THE ACFT AUTOLEVELED AT FL280. THE AUTOPLT WAS STILL IN THE ALT ACQUIRE MODE WHEN ATC GAVE US PLT'S DISCRETION BACK DOWN TO FL240. THE FO PUT FL240 IN THE ALT ALERT WINDOW WITH THE AUTOPLT STILL IN THE ALT ACQUIRE MODE. THE AUTOPLT DID NOT CAPTURE FL280 AND OVERSHOT FL280 BY 500 FT, BEFORE I NOTICED IT AND MADE A MANUAL CORRECTION. NO COMMENT WAS MADE BY ATC. WE CONTINUED OUR DSCNT NORMALLY.

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.