Light transport and ATC have misinterp of clearance given. Altitude deviation.

Attributes
ACN	247907
Time
Date	199307
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : den
State Reference	CO
Altitude	msl bound lower : 20000 msl bound upper : 21800
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	general aviation : personal
Make Model Name	Light Transport
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : cfi pilot : atp pilot : commercial
Experience	flight time last 90 days : 90 flight time total : 5100 flight time type : 150
ASRS Report	247907
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We departed apa. Initial heading was 320 degrees, initial altitude 8000 ft MSL from apa tower. Departure assigned heading 300 degrees, altitude 9000 ft, center assigned heading 245 degrees, altitude FL200. We requested and received 20 degrees left for WX. PNF requested 'how about higher for light transport. Maybe 220 or 240.' the controller said, 'approved.' PNF said, 'roger, climbing 240.' next, the controller said fly heading 260, 'that should take you around the north edge and keep you clear of traffic.' PNF read back, 'heading 260, FL240.' controller said, 'negative, maintain FL200.' we were climbing through FL215, maximum altitude was FL218. I immediately descended to FL200. We had just leveled off at FL200 when the controller said, 'maintain FL200 traffic 11 O'clock, 5 mi at FL210.' we said, 'roger.' I pride myself in using proper terminology, but let my guard down.

Original NASA ASRS Text

Title: LTT AND ATC HAVE MISINTERP OF CLRNC GIVEN. ALTDEV.

Narrative: WE DEPARTED APA. INITIAL HDG WAS 320 DEGS, INITIAL ALT 8000 FT MSL FROM APA TWR. DEP ASSIGNED HDG 300 DEGS, ALT 9000 FT, CTR ASSIGNED HDG 245 DEGS, ALT FL200. WE REQUESTED AND RECEIVED 20 DEGS L FOR WX. PNF REQUESTED 'HOW ABOUT HIGHER FOR LTT. MAYBE 220 OR 240.' THE CTLR SAID, 'APPROVED.' PNF SAID, 'ROGER, CLBING 240.' NEXT, THE CTLR SAID FLY HDG 260, 'THAT SHOULD TAKE YOU AROUND THE N EDGE AND KEEP YOU CLR OF TFC.' PNF READ BACK, 'HDG 260, FL240.' CTLR SAID, 'NEGATIVE, MAINTAIN FL200.' WE WERE CLBING THROUGH FL215, MAX ALT WAS FL218. I IMMEDIATELY DSNDED TO FL200. WE HAD JUST LEVELED OFF AT FL200 WHEN THE CTLR SAID, 'MAINTAIN FL200 TFC 11 O'CLOCK, 5 MI AT FL210.' WE SAID, 'ROGER.' I PRIDE MYSELF IN USING PROPER TERMINOLOGY, BUT LET MY GUARD DOWN.

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.