2 smas have near midair collision while on base final approach at vny.

Attributes
ACN	230007
Time
Date	199301
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : vny
State Reference	CA
Altitude	msl bound lower : 2000 msl bound upper : 2000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : vny
Operator	general aviation : instructional
Make Model Name	Small Aircraft
Flight Phase	other
Flight Plan	None
Aircraft 2
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	other
Person 1
Affiliation	Other
Function	other personnel other
Qualification	pilot : instrument
Experience	flight time last 90 days : 30 flight time total : 330 flight time type : 75
ASRS Report	230007
Person 2
Affiliation	Other
Function	flight crew : single pilot
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 200 vertical : 100
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

Contact was made with tower. We were cleared to 34L with a right base. Upon making right base, we were told to turn 180 degrees and base would be called approximately 1 NM from the mountains. We advised vny tower that this heading was inappropriate and we were in a collision course with the terrain. Vny advised us to turn base and cleared us to land #2. There then seemed to be some confusion in the tower as to identing us and the #1 aircraft. I turned on the landing light and advised the tower. Tower responded he 'had us is sight' and we were cleared to land #2 behind the small aircraft. Look out and down at my 1 O'clock low position less than 300 ft was the small aircraft. Evasive action was taken and tower was advised of action taken and the reason. Upon reentering final the landing was uneventful. All controllers and tower personnel were advised 'coast approach has advised us that our transponder was not functioning properly' and all handling personnel except vny tower acknowledged this and made all attempts to positively identify us from all other aircraft.

Original NASA ASRS Text

Title: 2 SMAS HAVE NMAC WHILE ON BASE FINAL APCH AT VNY.

Narrative: CONTACT WAS MADE WITH TWR. WE WERE CLRED TO 34L WITH A R BASE. UPON MAKING R BASE, WE WERE TOLD TO TURN 180 DEGS AND BASE WOULD BE CALLED APPROX 1 NM FROM THE MOUNTAINS. WE ADVISED VNY TWR THAT THIS HDG WAS INAPPROPRIATE AND WE WERE IN A COLLISION COURSE WITH THE TERRAIN. VNY ADVISED US TO TURN BASE AND CLRED US TO LAND #2. THERE THEN SEEMED TO BE SOME CONFUSION IN THE TWR AS TO IDENTING US AND THE #1 ACFT. I TURNED ON THE LNDG LIGHT AND ADVISED THE TWR. TWR RESPONDED HE 'HAD US IS SIGHT' AND WE WERE CLRED TO LAND #2 BEHIND THE SMA. LOOK OUT AND DOWN AT MY 1 O'CLOCK LOW POS LESS THAN 300 FT WAS THE SMA. EVASIVE ACTION WAS TAKEN AND TWR WAS ADVISED OF ACTION TAKEN AND THE REASON. UPON REENTERING FINAL THE LNDG WAS UNEVENTFUL. ALL CTLRS AND TWR PERSONNEL WERE ADVISED 'COAST APCH HAS ADVISED US THAT OUR XPONDER WAS NOT FUNCTIONING PROPERLY' AND ALL HANDLING PERSONNEL EXCEPT VNY TWR ACKNOWLEDGED THIS AND MADE ALL ATTEMPTS TO POSITIVELY IDENT US FROM ALL OTHER ACFT.

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.