An light transport air carrier crew made a go around in response to a TCASII alert.

Attributes
ACN	239342
Time
Date	199304
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : abe
State Reference	PA
Altitude	msl bound lower : 2300 msl bound upper : 2300
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : abe
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Navigation In Use	Other Other
Flight Phase	descent : approach landing : go around
Route In Use	approach : straight in
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 245 flight time total : 4800 flight time type : 1000
ASRS Report	239342
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Got TA TCASII alert while on localizer and GS to abe, PA. The particular plane we were in gives TA information only, no RA commands because the newer transponder hasn't been installed yet. The aircraft showing on the TCASII was 800 ft below us in level flight a few mi ahead. We would have collided had we remained on the localizer and GS since the other aircraft was flying toward us. The allentown tower did not pick up the offending aircraft on their radar, and since we were in the clouds and couldn't pick up the aircraft visually, we advised approach control that we were going missed approach. They vectored us back around to land without incident. Additionally, the allentown approach/tower personnel were unaware that we were TCASII equipped. Apparently the dispatcher failed to put it in the flight information. Callback conversation with reporter revealed the following information: the reporting pilot has since found a small airport right at the location of the reported TCASII incident. Very possibly the intruding aircraft was taxiing with its transponder on, or flying in the traffic pattern under VFR, but under a low ceiling.

Original NASA ASRS Text

Title: AN LTT ACR CREW MADE A GAR IN RESPONSE TO A TCASII ALERT.

Narrative: GOT TA TCASII ALERT WHILE ON LOC AND GS TO ABE, PA. THE PARTICULAR PLANE WE WERE IN GIVES TA INFO ONLY, NO RA COMMANDS BECAUSE THE NEWER XPONDER HASN'T BEEN INSTALLED YET. THE ACFT SHOWING ON THE TCASII WAS 800 FT BELOW US IN LEVEL FLT A FEW MI AHEAD. WE WOULD HAVE COLLIDED HAD WE REMAINED ON THE LOC AND GS SINCE THE OTHER ACFT WAS FLYING TOWARD US. THE ALLENTOWN TWR DID NOT PICK UP THE OFFENDING ACFT ON THEIR RADAR, AND SINCE WE WERE IN THE CLOUDS AND COULDN'T PICK UP THE ACFT VISUALLY, WE ADVISED APCH CTL THAT WE WERE GOING MISSED APCH. THEY VECTORED US BACK AROUND TO LAND WITHOUT INCIDENT. ADDITIONALLY, THE ALLENTOWN APCH/TWR PERSONNEL WERE UNAWARE THAT WE WERE TCASII EQUIPPED. APPARENTLY THE DISPATCHER FAILED TO PUT IT IN THE FLT INFO. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTING PLT HAS SINCE FOUND A SMALL ARPT RIGHT AT THE LOCATION OF THE RPTED TCASII INCIDENT. VERY POSSIBLY THE INTRUDING ACFT WAS TAXIING WITH ITS XPONDER ON, OR FLYING IN THE TFC PATTERN UNDER VFR, BUT UNDER A LOW CEILING.

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.