Air carrier X requested altitude change to avoid TCASII TA RA.

Attributes
ACN	285401
Time
Date	199410
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : pdt
State Reference	OR
Altitude	msl bound lower : 16000 msl bound upper : 16000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dtw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : direct enroute airway : zse
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 10
ASRS Report	285401
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 1500
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Air carrier X was wbound on V-4, boi to sea. I issued VFR traffic at 12 O'clock, 5 mi, opposite direction, mode C indication of 15600 ft. Air carrier X requested 17000 ft. I issued 17000 ft and made the computer entry, did the strip marking, and coordinated 17000 ft wrong altitude for direction (wadof). Less than 2 mins later (after passing the VFR target), air carrier X requested 16000 ft. I issued the altitude mode, the computer entry, and did the strip marking. The NAS computer system generated 2 sets of strips, one for each altitude amendment that had to be reviewed and posted or discarded. I asked X if the altitude change was because of TCASII. He advised that the altitude 'was to avoid a TCASII event.' the altitude changes were unneeded workload. Pilots should not be requesting clearance amendments for avoidance of potential TCASII events. The workload is distracting.

Original NASA ASRS Text

Title: ACR X REQUESTED ALT CHANGE TO AVOID TCASII TA RA.

Narrative: ACR X WAS WBOUND ON V-4, BOI TO SEA. I ISSUED VFR TFC AT 12 O'CLOCK, 5 MI, OPPOSITE DIRECTION, MODE C INDICATION OF 15600 FT. ACR X REQUESTED 17000 FT. I ISSUED 17000 FT AND MADE THE COMPUTER ENTRY, DID THE STRIP MARKING, AND COORDINATED 17000 FT WRONG ALT FOR DIRECTION (WADOF). LESS THAN 2 MINS LATER (AFTER PASSING THE VFR TARGET), ACR X REQUESTED 16000 FT. I ISSUED THE ALT MODE, THE COMPUTER ENTRY, AND DID THE STRIP MARKING. THE NAS COMPUTER SYS GENERATED 2 SETS OF STRIPS, ONE FOR EACH ALT AMENDMENT THAT HAD TO BE REVIEWED AND POSTED OR DISCARDED. I ASKED X IF THE ALT CHANGE WAS BECAUSE OF TCASII. HE ADVISED THAT THE ALT 'WAS TO AVOID A TCASII EVENT.' THE ALT CHANGES WERE UNNEEDED WORKLOAD. PLTS SHOULD NOT BE REQUESTING CLRNC AMENDMENTS FOR AVOIDANCE OF POTENTIAL TCASII EVENTS. THE WORKLOAD IS DISTRACTING.

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.