Q400 flight crew reports being cleared out of their cruise altitude 150 NM from their destination. W...

Narrative:

First descent from FL240 down to FL220 given when well east of rno. Second descent from FL220 down to 16;000 ft given while near rno. I asked ZOA center if the descent was for traffic. ZOA center replied; 'I'm not in the habit of explaining my instructions to pilots.' I replied that we were still a long ways from our destination and that flying at the lower altitudes increases our fuel burn but that we are descending from FL220 down to 16;000 ft. A few minutes later at approximately FL190 ZOA center says he does not see us turning. I advise that we were not assigned a new heading. ZOA controller says he told us to turn left 20 degrees. We comply. Both first officer and captain do not recall a new heading assignment being given nor did I read one back during the initial descent clearance. ZOA center then tells us to expedite descent due to traffic. No traffic was ever pointed out to us and the only TCAS target displayed was at our 2:00 o'clock position; 18 miles and 1;400 ft below our altitude. ZOA controller then advised us of 'possible pilot deviation' and gave us a phone number to call. I think the ATC controller did not like me asking if the descent was for traffic I guess. I was just trying to be kept in the loop and be advised of any conflicting traffic in the area.

Original NASA ASRS Text

Title: Q400 Flight Crew reports being cleared out of their cruise altitude 150 NM from their destination. When the ZOA Controller is queried as to the reason for the early descent evasive answers are provided.

Narrative: First descent from FL240 down to FL220 given when well east of RNO. Second descent from FL220 down to 16;000 FT given while near RNO. I asked ZOA Center if the descent was for traffic. ZOA Center replied; 'I'm not in the habit of explaining my instructions to pilots.' I replied that we were still a long ways from our destination and that flying at the lower altitudes increases our fuel burn but that we are descending from FL220 down to 16;000 FT. A few minutes later at approximately FL190 ZOA Center says he does not see us turning. I advise that we were not assigned a new heading. ZOA Controller says he told us to turn left 20 degrees. We comply. Both First Officer and Captain do not recall a new heading assignment being given nor did I read one back during the initial descent clearance. ZOA Center then tells us to expedite descent due to traffic. No traffic was ever pointed out to us and the only TCAS target displayed was at our 2:00 o'clock position; 18 miles and 1;400 FT below our altitude. ZOA Controller then advised us of 'possible pilot deviation' and gave us a phone number to call. I think the ATC Controller did not like me asking if the descent was for traffic I guess. I was just trying to be kept in the loop and be advised of any conflicting traffic in the area.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	910723
Time
Date	201009
Local Time Of Day	0601-1200
Place
Locale Reference	ZOA.ARTCC
State Reference	CA
Aircraft 1
Make Model Name	Q400
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Pilot Flying
Events
Anomaly	ATC Issue All Types

Q400 flight crew reports being cleared out of their cruise altitude 150 NM from their destination. When the ZOA controller is queried as to the reason for the early descent evasive answers are provided.