B737 crew had altitude deviation in ZHU class a airspace.

Attributes
ACN	486321
Time
Date	200009
Day	Mon
Local Time Of Day	0601 To 1200
Place
State Reference	LA
Altitude	msl bound lower : 33000 msl bound upper : 34000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu.artcc tracon : a90.tracon
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zhu.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : flight engineer pilot : multi engine
Experience	flight time last 90 days : 230 flight time total : 2550 flight time type : 250
ASRS Report	486321
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 162 flight time total : 7365 flight time type : 960
ASRS Report	485750
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : company policies non adherence : published procedure other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned altitude none taken : detected after the fact
Miss Distance	horizontal : 18000 vertical : 1000
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Cruising at FL330, first officer requested flight planned altitude of FL350. ZHU advised us of crossing traffic at FL350, and 'expect FL350' once clear of traffic. First officer acknowledged. Captain misunderstood radio transmission and initiated climb to FL350. At approximately FL340, ZHU queried us about our altitude. Captain disconnected the autoplt and expedited a descent to FL330. First officer was unaware of captain's initiation of climb. Human performance considerations: 1) cockpit CRM and procedures breakdown. 2) crossing traffic held first officer's attention as a visual was obtained. 3) confirmation of new altitude of FL350 was not obtained by the captain (procedure). ATC would have been queried and this deviation would not have occurred. Supplemental information from acn 485750: cruising at FL330. First officer requested flight plan altitude of FL350 from ATC (houston 132.7) first officer heard and read back 'expect FL350' and traffic call. Captain understood clearance and readback was to FL350. First officer was acknowledging/pointing our traffic at '2 O'clock position' as captain dialed FL350 in altitude window. ATC questioned altitude climbing through approximately FL338. Autoplt disconnected and aircraft descended to FL330. No TCASII warning received.

Original NASA ASRS Text

Title: B737 CREW HAD ALTDEV IN ZHU CLASS A AIRSPACE.

Narrative: CRUISING AT FL330, FO REQUESTED FLT PLANNED ALT OF FL350. ZHU ADVISED US OF XING TFC AT FL350, AND 'EXPECT FL350' ONCE CLR OF TFC. FO ACKNOWLEDGED. CAPT MISUNDERSTOOD RADIO XMISSION AND INITIATED CLB TO FL350. AT APPROX FL340, ZHU QUERIED US ABOUT OUR ALT. CAPT DISCONNECTED THE AUTOPLT AND EXPEDITED A DSCNT TO FL330. FO WAS UNAWARE OF CAPT'S INITIATION OF CLB. HUMAN PERFORMANCE CONSIDERATIONS: 1) COCKPIT CRM AND PROCS BREAKDOWN. 2) XING TFC HELD FO'S ATTN AS A VISUAL WAS OBTAINED. 3) CONFIRMATION OF NEW ALT OF FL350 WAS NOT OBTAINED BY THE CAPT (PROC). ATC WOULD HAVE BEEN QUERIED AND THIS DEV WOULD NOT HAVE OCCURRED. SUPPLEMENTAL INFO FROM ACN 485750: CRUISING AT FL330. FO REQUESTED FLT PLAN ALT OF FL350 FROM ATC (HOUSTON 132.7) FO HEARD AND READ BACK 'EXPECT FL350' AND TFC CALL. CAPT UNDERSTOOD CLRNC AND READBACK WAS TO FL350. FO WAS ACKNOWLEDGING/POINTING OUR TFC AT '2 O'CLOCK POS' AS CAPT DIALED FL350 IN ALT WINDOW. ATC QUESTIONED ALT CLBING THROUGH APPROX FL338. AUTOPLT DISCONNECTED AND ACFT DSNDED TO FL330. NO TCASII WARNING RECEIVED.

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.