Gulfstream G-100 astra and a diamond katana had less than comfortable separation in baf class D airs...

Attributes
ACN	592483
Time
Date	200306
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : baf.airport
State Reference	MA
Altitude	agl single value : 1500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : baf.tower tower : dtw.tower
Operator	general aviation : corporate
Make Model Name	IAI1125 (Astra)
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	approach : traffic pattern
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : baf.tower
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent : approach
Person 1
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : multi engine pilot : atp pilot : flight engineer pilot : cfi
Experience	controller military : 11 controller non radar : 21 controller radar : 21 flight time last 90 days : 120 flight time total : 5300 flight time type : 148
ASRS Report	592483
Person 2
Affiliation	company : corporate
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical non adherence : required legal separation
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued advisory flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 2000 vertical : 100
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance FAA
Primary Problem	Flight Crew Human Performance

Narrative:

Established on 5 NM right base and cleared to land. Tower told the katana on a left downwind of our position, but did not tell the katana to extend downwind and wait for tower to call base turn. The katana turned left base and we aggressively turned toward the field to avoid a midair as tower then told the katana to execute a left 360 degree turn. Tower tried to persuade us from filing this report.

Original NASA ASRS Text

Title: GULFSTREAM G-100 ASTRA AND A DIAMOND KATANA HAD LESS THAN COMFORTABLE SEPARATION IN BAF CLASS D AIRSPACE.

Narrative: ESTABLISHED ON 5 NM R BASE AND CLRED TO LAND. TWR TOLD THE KATANA ON A L DOWNWIND OF OUR POS, BUT DID NOT TELL THE KATANA TO EXTEND DOWNWIND AND WAIT FOR TWR TO CALL BASE TURN. THE KATANA TURNED L BASE AND WE AGGRESSIVELY TURNED TOWARD THE FIELD TO AVOID A MIDAIR AS TWR THEN TOLD THE KATANA TO EXECUTE A L 360 DEG TURN. TWR TRIED TO PERSUADE US FROM FILING THIS RPT.

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.

Gulfstream G-100 astra and a diamond katana had less than comfortable separation in baf class D airspace.