Potential conflict. Less than standard separation. Near midair collision.

Attributes
ACN	109736
Time
Date	198904
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sna
State Reference	CA
Altitude	msl bound lower : 1000 msl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sna tower : sjc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport
Navigation In Use	Other
Flight Phase	climbout : takeoff climbout : initial
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Transport
Flight Phase	climbout : initial climbout : intermediate altitude
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 220 flight time total : 10000 flight time type : 1200
ASRS Report	109736
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : nmac other anomaly other other spatial deviation
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	Pilot Deviation

Narrative:

We were on departure from sna (orange county, ca) runway 19R on a musel 5 departure. Another light aircraft (blue and white, either large single engine or light twin) apparently had taken off 19L just prior to our departure and was on another tower frequency. No traffic was called to us at any time. During our climb I saw him ahead of us on a diverging southeast heading. Just after we had made our 'cutback power' reduction I noticed he had turned to a more southerly heading, paralleling our course. As we pulled even with him he made a sharp right turn towards us. We added full power and climbed as he made an evasive left turn and slid underneath and to the rear of us. We advised tower and they apologized saying he was on another frequency and said he had us in sight. If so he had a death wish! If aircraft are going to cross another active runway (on ground or in air) they should be in contact with the person controling that runway.

Original NASA ASRS Text

Title: POTENTIAL CONFLICT. LESS THAN STANDARD SEPARATION. NMAC.

Narrative: WE WERE ON DEP FROM SNA (ORANGE COUNTY, CA) RWY 19R ON A MUSEL 5 DEP. ANOTHER LIGHT ACFT (BLUE AND WHITE, EITHER LARGE SINGLE ENGINE OR LIGHT TWIN) APPARENTLY HAD TAKEN OFF 19L JUST PRIOR TO OUR DEP AND WAS ON ANOTHER TWR FREQ. NO TFC WAS CALLED TO US AT ANY TIME. DURING OUR CLIMB I SAW HIM AHEAD OF US ON A DIVERGING SE HDG. JUST AFTER WE HAD MADE OUR 'CUTBACK POWER' REDUCTION I NOTICED HE HAD TURNED TO A MORE SOUTHERLY HDG, PARALLELING OUR COURSE. AS WE PULLED EVEN WITH HIM HE MADE A SHARP RIGHT TURN TOWARDS US. WE ADDED FULL POWER AND CLIMBED AS HE MADE AN EVASIVE LEFT TURN AND SLID UNDERNEATH AND TO THE REAR OF US. WE ADVISED TWR AND THEY APOLOGIZED SAYING HE WAS ON ANOTHER FREQ AND SAID HE HAD US IN SIGHT. IF SO HE HAD A DEATH WISH! IF ACFT ARE GOING TO CROSS ANOTHER ACTIVE RWY (ON GND OR IN AIR) THEY SHOULD BE IN CONTACT WITH THE PERSON CTLING THAT RWY.

Data retrieved from NASA's ASRS site as of August 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.