An air carrier EMB120 flight crew has an encounter with a PA31 freighter while on approach to acv. T...

Attributes
ACN	363292
Time
Date	199703
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : acv
State Reference	CA
Altitude	msl bound lower : 1700 msl bound upper : 1700
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach landing : go around
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Make Model Name	PA-31 Navajo Chieftan/Mojave/Navajo T1020
Operating Under FAR Part	Part 135
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 270 flight time total : 12000 flight time type : 2000
ASRS Report	363292
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : airborne less severe non adherence : far non adherence : published procedure other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action other other
Consequence	Other
Miss Distance	horizontal : 1000 vertical : 400
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Cleared for ILS to acv by ZSE and switched to acv advisory 20 NM out to check in. No reported traffic and WX update. Heard a freighter (navato) ask FSS about fuel, assumed he was on ground. Just inside FAF, my first officer pointed out traffic at 10 O'clock and 1 mi, low. I turned right and went missed. First officer reported intentions and then freighter made position report. He continued base to final turn and we (I) flew a full pattern. Freighter later said that since he hadn't seen any other traffic, he skipped a position report! As far as the bendix tcasi, it's junk! No other traffic for at least 50 mi and the unit did not display the target until he was behind me. The FAA really needs to issue an airworthiness directive on the upcoming software modification to increase the power output. The arac SC147 committee to the FAA doesn't feel this strongly, unfortunately, and the modification will more than likely be optional. Callback conversation with reporter revealed the following information: this reporter has been working for some time to change/improve the tcasi performance and is currently on a committee that deals with user problems in the NAS. He did say, however, that he does not think that tcasi can ever assure the degree of safety that the present TCASII provides since with tcasi there is no guidance to escape an intruder.

Original NASA ASRS Text

Title: AN ACR EMB120 FLC HAS AN ENCOUNTER WITH A PA31 FREIGHTER WHILE ON APCH TO ACV. THE RPTR AVOIDED THE FREIGHTER BY GOING AROUND AND RE-ENTERING THE PATTERN.

Narrative: CLRED FOR ILS TO ACV BY ZSE AND SWITCHED TO ACV ADVISORY 20 NM OUT TO CHK IN. NO RPTED TFC AND WX UPDATE. HEARD A FREIGHTER (NAVATO) ASK FSS ABOUT FUEL, ASSUMED HE WAS ON GND. JUST INSIDE FAF, MY FO POINTED OUT TFC AT 10 O'CLOCK AND 1 MI, LOW. I TURNED R AND WENT MISSED. FO RPTED INTENTIONS AND THEN FREIGHTER MADE POS RPT. HE CONTINUED BASE TO FINAL TURN AND WE (I) FLEW A FULL PATTERN. FREIGHTER LATER SAID THAT SINCE HE HADN'T SEEN ANY OTHER TFC, HE SKIPPED A POS RPT! AS FAR AS THE BENDIX TCASI, IT'S JUNK! NO OTHER TFC FOR AT LEAST 50 MI AND THE UNIT DID NOT DISPLAY THE TARGET UNTIL HE WAS BEHIND ME. THE FAA REALLY NEEDS TO ISSUE AN AIRWORTHINESS DIRECTIVE ON THE UPCOMING SOFTWARE MODIFICATION TO INCREASE THE PWR OUTPUT. THE ARAC SC147 COMMITTEE TO THE FAA DOESN'T FEEL THIS STRONGLY, UNFORTUNATELY, AND THE MODIFICATION WILL MORE THAN LIKELY BE OPTIONAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS RPTR HAS BEEN WORKING FOR SOME TIME TO CHANGE/IMPROVE THE TCASI PERFORMANCE AND IS CURRENTLY ON A COMMITTEE THAT DEALS WITH USER PROBS IN THE NAS. HE DID SAY, HOWEVER, THAT HE DOES NOT THINK THAT TCASI CAN EVER ASSURE THE DEG OF SAFETY THAT THE PRESENT TCASII PROVIDES SINCE WITH TCASI THERE IS NO GUIDANCE TO ESCAPE AN INTRUDER.

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.

An air carrier EMB120 flight crew has an encounter with a PA31 freighter while on approach to acv. The reporter avoided the freighter by going around and re-entering the pattern.