ZDV controller questions turbojet cpr flight crew observing further descent below MVA.

Attributes
ACN	534493
Time
Date	200201
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : tex.airport
State Reference	CO
Altitude	msl bound lower : 14000 msl bound upper : 1500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : cfi pilot : atp
Experience	flight time last 90 days : 120 flight time total : 3200 flight time type : 300
ASRS Report	534493
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : ground less severe ground encounters other non adherence : far non adherence : published procedure
Independent Detector	atc equipment other atc equipment : radar other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued advisory controller : issued new clearance
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

While approaching tex for a planned visual approach, we were last assigned 15000 ft altitude. The center controller advised his MVA in the area was 16000 ft. He then asked if we were able to maintain our own terrain separation. We advised that we could. Controller then told us to maintain our own terrain separation. I interpreted this to mean we could maneuver and descend as long as terrain separation could be maintained. I initiated a gradual descent and upon reaching 14000 ft, controller inquired about altitude and informed us last assigned altitude was 15000 ft. He then asked if we were canceling IFR, which we then did. Controller advised 'no problem, cancellation received.' while no violation occurred technically, one could have been assessed.

Original NASA ASRS Text

Title: ZDV CTLR QUESTIONS TURBOJET CPR FLC OBSERVING FURTHER DSCNT BELOW MVA.

Narrative: WHILE APCHING TEX FOR A PLANNED VISUAL APCH, WE WERE LAST ASSIGNED 15000 FT ALT. THE CTR CTLR ADVISED HIS MVA IN THE AREA WAS 16000 FT. HE THEN ASKED IF WE WERE ABLE TO MAINTAIN OUR OWN TERRAIN SEPARATION. WE ADVISED THAT WE COULD. CTLR THEN TOLD US TO MAINTAIN OUR OWN TERRAIN SEPARATION. I INTERPED THIS TO MEAN WE COULD MANEUVER AND DSND AS LONG AS TERRAIN SEPARATION COULD BE MAINTAINED. I INITIATED A GRADUAL DSCNT AND UPON REACHING 14000 FT, CTLR INQUIRED ABOUT ALT AND INFORMED US LAST ASSIGNED ALT WAS 15000 FT. HE THEN ASKED IF WE WERE CANCELING IFR, WHICH WE THEN DID. CTLR ADVISED 'NO PROB, CANCELLATION RECEIVED.' WHILE NO VIOLATION OCCURRED TECHNICALLY, ONE COULD HAVE BEEN ASSESSED.

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.