Small transport X had near midair collision with small aircraft Y.

Attributes
ACN	141680
Time
Date	199004
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : oak
State Reference	CA
Altitude	msl bound lower : 2900 msl bound upper : 3500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : oak tower : oak tower : ont
Operator	other
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	climbout : intermediate altitude
Route In Use	approach : visual departure other
Flight Plan	VFR
Aircraft 2
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : instrument pilot : commercial
Experience	flight time last 90 days : 100 flight time total : 5985 flight time type : 27
ASRS Report	141680
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Events
Anomaly	conflict : nmac
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 100 vertical : 75
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	Inter Facility Coordination Failure

Narrative:

Small transport X departed from oak runway 27R for vectors to hayward. Localizer approach. At lake chabot I encountered traffic at 1 O'clock - 3 O'clock same altitude (2900'). Avoided small aircraft Y by climbing to 3500'. Callback conversation with reporter revealed the following information. The reporter stated he had been instructed to proceed to lake chabot. About 4 mi northeast of oak he was issued small aircraft Y as traffic, instructed to remain clear of the sfo TCA and contact bay departure control. He saw the small aircraft and took evasive action. Reporter reported near midair collision to bay supervisor after landing. Bay departure control was working the small aircraft Y and issued traffic but the small aircraft Y had not seen small transport X.

Original NASA ASRS Text

Title: SMT X HAD NMAC WITH SMA Y.

Narrative: SMT X DEPARTED FROM OAK RWY 27R FOR VECTORS TO HAYWARD. LOC APCH. AT LAKE CHABOT I ENCOUNTERED TFC AT 1 O'CLOCK - 3 O'CLOCK SAME ALT (2900'). AVOIDED SMA Y BY CLBING TO 3500'. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. THE RPTR STATED HE HAD BEEN INSTRUCTED TO PROCEED TO LAKE CHABOT. ABOUT 4 MI NE OF OAK HE WAS ISSUED SMA Y AS TFC, INSTRUCTED TO REMAIN CLR OF THE SFO TCA AND CONTACT BAY DEP CTL. HE SAW THE SMA AND TOOK EVASIVE ACTION. RPTR RPTED NMAC TO BAY SUPVR AFTER LNDG. BAY DEP CTL WAS WORKING THE SMA Y AND ISSUED TFC BUT THE SMA Y HAD NOT SEEN SMT X.

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.