Began descent from altitude without clearance.

Attributes
ACN	92314
Time
Date	198808
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cos
State Reference	CO
Altitude	msl bound lower : 11200 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : cos
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 20 flight time total : 1100 flight time type : 300
ASRS Report	92314
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was on an IFR flight plan from grand junction, co to co springs, co, via V26 V244 at 17,000 MSL. WX was VMC with cumulus buildups and thunderstorm activity with moderate turbulence requiring flight deviations approved by denver center. Upon approaching the vicinity of pueblo, co, and the co springs area, I had requested and received permission to descend from 17,000' MSL to 12,000' MSL in a step-down fashion from denver center. I was turned over to co springs approach control and radar contact was acknowledged. As I approached co springs with the airport in sight, I repeatedly called on assigned approach frequency with requests to descend, and I continued at my assigned altitude. When I felt it was no longer safe to continue at that altitude and was getting no response from approach, I began a VFR descent and was immediately told I had no permission to do so at that time. I feel approach should have at least told me to stand by instead of ignoring my xmissions. There were no other xmissions on this frequency at the time of this occurrence, so I do not feel that can be used as an excuse. It has been my experience that it is not uncommon for the controllers to ignore xmissions, and then cause piston aircraft to descend in a rapid and unsafe manner of operation. This can also cause passenger discomfort in unpressurized aircraft. Air traffic controllers should be made more aware of the needs of this type of aircraft operation. Callback conversation with reporter revealed the following: reporter admits he should have maintained his altitude until receiving clearance. Could have cancelled IFR but really wanted to hang on to the clearance. Would have had no problem if the controller had advised to stand by, but he got no response. Descent was made in VFR conditions and when the controller called, he said it was ok to stay at the lower altitude. No explanation of why his calls were not acknowledged. Did admit he wanted to get started down because his wife has problem clearing her ears in descent.

Original NASA ASRS Text

Title: BEGAN DESCENT FROM ALT WITHOUT CLRNC.

Narrative: I WAS ON AN IFR FLT PLAN FROM GRAND JUNCTION, CO TO CO SPRINGS, CO, VIA V26 V244 AT 17,000 MSL. WX WAS VMC WITH CUMULUS BUILDUPS AND TSTM ACTIVITY WITH MODERATE TURB REQUIRING FLT DEVIATIONS APPROVED BY DENVER CENTER. UPON APCHING THE VICINITY OF PUEBLO, CO, AND THE CO SPRINGS AREA, I HAD REQUESTED AND RECEIVED PERMISSION TO DSND FROM 17,000' MSL TO 12,000' MSL IN A STEP-DOWN FASHION FROM DENVER CENTER. I WAS TURNED OVER TO CO SPRINGS APCH CTL AND RADAR CONTACT WAS ACKNOWLEDGED. AS I APCHED CO SPRINGS WITH THE ARPT IN SIGHT, I REPEATEDLY CALLED ON ASSIGNED APCH FREQ WITH REQUESTS TO DSND, AND I CONTINUED AT MY ASSIGNED ALT. WHEN I FELT IT WAS NO LONGER SAFE TO CONTINUE AT THAT ALT AND WAS GETTING NO RESPONSE FROM APCH, I BEGAN A VFR DSCNT AND WAS IMMEDIATELY TOLD I HAD NO PERMISSION TO DO SO AT THAT TIME. I FEEL APCH SHOULD HAVE AT LEAST TOLD ME TO STAND BY INSTEAD OF IGNORING MY XMISSIONS. THERE WERE NO OTHER XMISSIONS ON THIS FREQ AT THE TIME OF THIS OCCURRENCE, SO I DO NOT FEEL THAT CAN BE USED AS AN EXCUSE. IT HAS BEEN MY EXPERIENCE THAT IT IS NOT UNCOMMON FOR THE CTLRS TO IGNORE XMISSIONS, AND THEN CAUSE PISTON ACFT TO DSND IN A RAPID AND UNSAFE MANNER OF OPERATION. THIS CAN ALSO CAUSE PAX DISCOMFORT IN UNPRESSURIZED ACFT. AIR TFC CTLRS SHOULD BE MADE MORE AWARE OF THE NEEDS OF THIS TYPE OF ACFT OPERATION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR ADMITS HE SHOULD HAVE MAINTAINED HIS ALT UNTIL RECEIVING CLRNC. COULD HAVE CANCELLED IFR BUT REALLY WANTED TO HANG ON TO THE CLRNC. WOULD HAVE HAD NO PROB IF THE CTLR HAD ADVISED TO STAND BY, BUT HE GOT NO RESPONSE. DSCNT WAS MADE IN VFR CONDITIONS AND WHEN THE CTLR CALLED, HE SAID IT WAS OK TO STAY AT THE LOWER ALT. NO EXPLANATION OF WHY HIS CALLS WERE NOT ACKNOWLEDGED. DID ADMIT HE WANTED TO GET STARTED DOWN BECAUSE HIS WIFE HAS PROB CLRING HER EARS IN DSCNT.

Data retrieved from NASA's ASRS site as of August 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.