Widebody transport has TCASII RA for targets not appearing on radar.

Attributes
ACN	249067
Time
Date	199308
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bos
State Reference	MA
Altitude	msl bound lower : 1500 msl bound upper : 1500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bos tower : atl
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 21000 flight time type : 1700
ASRS Report	249067
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Took off on runway 9 at bos with a straight out climb as per the SID. At 1500 ft, TCASII sounded an RA, first 'reduce climb' then 'descend.' a TCASII target was observed at 10 O'clock and 2-3 mi plus 200 ft and converging rapidly. Target passed above us then disappeared from scope. As climb was resumed a second RA was sounded. Target was again observed at 10 O'clock plus 200 ft but at 7 mi range. Target followed a similar path and crossed above us at plus 200 ft then disappeared. At no time was any visual contact made nor did ATC observe traffic on radar.

Original NASA ASRS Text

Title: WDB HAS TCASII RA FOR TARGETS NOT APPEARING ON RADAR.

Narrative: TOOK OFF ON RWY 9 AT BOS WITH A STRAIGHT OUT CLB AS PER THE SID. AT 1500 FT, TCASII SOUNDED AN RA, FIRST 'REDUCE CLB' THEN 'DSND.' A TCASII TARGET WAS OBSERVED AT 10 O'CLOCK AND 2-3 MI PLUS 200 FT AND CONVERGING RAPIDLY. TARGET PASSED ABOVE US THEN DISAPPEARED FROM SCOPE. AS CLB WAS RESUMED A SECOND RA WAS SOUNDED. TARGET WAS AGAIN OBSERVED AT 10 O'CLOCK PLUS 200 FT BUT AT 7 MI RANGE. TARGET FOLLOWED A SIMILAR PATH AND CROSSED ABOVE US AT PLUS 200 FT THEN DISAPPEARED. AT NO TIME WAS ANY VISUAL CONTACT MADE NOR DID ATC OBSERVE TFC ON RADAR.

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.