Light transport commuter aircraft does not descend right away when cleared. Causes TCASII TA, then R...

Attributes
ACN	245711
Time
Date	199307
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : bpt
State Reference	TX
Altitude	msl bound lower : 23000 msl bound upper : 23000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zhu
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Navigation In Use	Other Other
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : cfi pilot : atp pilot : commercial
Experience	flight time last 90 days : 216 flight time total : 10280 flight time type : 1620
ASRS Report	245711
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe non adherence : clearance non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 19000 vertical : 700
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Approximately 25 mi prior to my planned descent point the controller assigned us a much lower altitude with no extra comment. Hoping for pilot's discretion, I delayed starting down and asked the first officer to handle our request. We were unable to get the message across on the busy frequency. I didn't notice a conflict until the TCASII issued a TA at approximately 10 O'clock and 7 mi. We started down and then we got an RA to descend. We promptly lost altitude until we were well clear of the other aircraft. During the RA the TCASII showed the other aircraft climbing, perhaps trying to avoid us. The controller also reaffirmed our need to descend but made no comment about the conflict. I should have promptly complied with my clearance and then made my request. It would be very beneficial for the controller to add to the pilot's awareness when workload permits.

Original NASA ASRS Text

Title: LTT COMMUTER ACFT DOES NOT DSND RIGHT AWAY WHEN CLRED. CAUSES TCASII TA, THEN RA.

Narrative: APPROX 25 MI PRIOR TO MY PLANNED DSCNT POINT THE CTLR ASSIGNED US A MUCH LOWER ALT WITH NO EXTRA COMMENT. HOPING FOR PLT'S DISCRETION, I DELAYED STARTING DOWN AND ASKED THE FO TO HANDLE OUR REQUEST. WE WERE UNABLE TO GET THE MESSAGE ACROSS ON THE BUSY FREQ. I DIDN'T NOTICE A CONFLICT UNTIL THE TCASII ISSUED A TA AT APPROX 10 O'CLOCK AND 7 MI. WE STARTED DOWN AND THEN WE GOT AN RA TO DSND. WE PROMPTLY LOST ALT UNTIL WE WERE WELL CLR OF THE OTHER ACFT. DURING THE RA THE TCASII SHOWED THE OTHER ACFT CLBING, PERHAPS TRYING TO AVOID US. THE CTLR ALSO REAFFIRMED OUR NEED TO DSND BUT MADE NO COMMENT ABOUT THE CONFLICT. I SHOULD HAVE PROMPTLY COMPLIED WITH MY CLRNC AND THEN MADE MY REQUEST. IT WOULD BE VERY BENEFICIAL FOR THE CTLR TO ADD TO THE PLT'S AWARENESS WHEN WORKLOAD PERMITS.

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.

Light transport commuter aircraft does not descend right away when cleared. Causes TCASII TA, then RA.