B737 crew had altitude overshoot in ZDV class a.

Attributes
ACN	475540
Time
Date	200006
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : den.airport
State Reference	CO
Altitude	msl bound lower : 31000 msl bound upper : 31500
Environment
Flight Conditions	Mixed
Weather Elements	Thunderstorm Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : multi engine pilot : atp pilot : cfi pilot : commercial pilot : flight engineer
Experience	flight time last 90 days : 240 flight time total : 10500 flight time type : 4000
ASRS Report	475540
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	altitude deviation : overshoot inflight encounter : turbulence inflight encounter : weather inflight encounter other non adherence : clearance
Independent Detector	other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance Weather Airspace Structure
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier flight abc den-yvr we encountered some WX at approximately FL300. We had leveled at FL290 when we asked for higher. FL310 was approved. During the climb from FL290 to FL310 we asked for a deviation for WX. It was a cell with a red center. There was some confusion about which side we could deviate on. We wanted to turn 20 degrees left but then ATC said there was inbound traffic to denver to our left and told us to turn right. I turned back approximately 20 degrees right of course, hand-flying. We encountered moderate turbulence and I gained approximately 500 ft. ATC then asked about our altitude but we were already correcting.

Original NASA ASRS Text

Title: B737 CREW HAD ALT OVERSHOOT IN ZDV CLASS A.

Narrative: ACR FLT ABC DEN-YVR WE ENCOUNTERED SOME WX AT APPROX FL300. WE HAD LEVELED AT FL290 WHEN WE ASKED FOR HIGHER. FL310 WAS APPROVED. DURING THE CLB FROM FL290 TO FL310 WE ASKED FOR A DEV FOR WX. IT WAS A CELL WITH A RED CTR. THERE WAS SOME CONFUSION ABOUT WHICH SIDE WE COULD DEVIATE ON. WE WANTED TO TURN 20 DEGS L BUT THEN ATC SAID THERE WAS INBOUND TFC TO DENVER TO OUR L AND TOLD US TO TURN R. I TURNED BACK APPROX 20 DEGS R OF COURSE, HAND-FLYING. WE ENCOUNTERED MODERATE TURB AND I GAINED APPROX 500 FT. ATC THEN ASKED ABOUT OUR ALT BUT WE WERE ALREADY CORRECTING.

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.