TCASII alert, for traffic not acquired by bwi TRACON radar, leads pilot of light transport to alter ...

Attributes
ACN	437292
Time
Date	199905
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mtn.airport
State Reference	MD
Altitude	msl single value : 3000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bwi.tracon
Operator	general aviation : corporate
Make Model Name	Beechjet 400
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : bwi.tracon
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : instrument pilot : multi engine pilot : atp
Experience	flight time last 90 days : 120 flight time total : 3890 flight time type : 1100
ASRS Report	437292
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe
Independent Detector	aircraft equipment : tcas
Miss Distance	horizontal : 7000 vertical : 1000
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

While approaching (mtn) on vectors we received a TCASII alert. The target was at our altitude on a collision course approximately 2 mi and closing. We altered course to the right until he passed behind us. It appeared he was in a slow climb, and we never saw the other aircraft. The local controller seemed very upset that we had deviated and said he had no traffic on his screen.

Original NASA ASRS Text

Title: TCASII ALERT, FOR TFC NOT ACQUIRED BY BWI TRACON RADAR, LEADS PLT OF LTT TO ALTER HEADING.

Narrative: WHILE APCHING (MTN) ON VECTORS WE RECEIVED A TCASII ALERT. THE TARGET WAS AT OUR ALT ON A COLLISION COURSE APPROX 2 MI AND CLOSING. WE ALTERED COURSE TO THE R UNTIL HE PASSED BEHIND US. IT APPEARED HE WAS IN A SLOW CLB, AND WE NEVER SAW THE OTHER ACFT. THE LCL CTLR SEEMED VERY UPSET THAT WE HAD DEVIATED AND SAID HE HAD NO TFC ON HIS SCREEN.

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.

TCASII alert, for traffic not acquired by bwi TRACON radar, leads pilot of light transport to alter heading.