Pilot of an L39 military jet trainer has near midair collision.

Attributes
ACN	554719
Time
Date	200207
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sts.airport
State Reference	CA
Altitude	msl single value : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sts.tower
Operator	general aviation : personal
Make Model Name	Military
Operating Under FAR Part	Part 91
Flight Plan	None
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : cfi pilot : atp pilot : flight engineer pilot : instrument pilot : commercial
Experience	flight time last 90 days : 18 flight time total : 20000 flight time type : 8
ASRS Report	554719
Person 2
Function	flight crew : single pilot
Events
Anomaly	conflict : nmac non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact none taken : insufficient time
Miss Distance	horizontal : 300 vertical : 50
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Operational Error

Narrative:

During descent for initial approach to sts, I passed a C172 (or C152) on its right side. I was indicating approximately 240 KTS, the other aircraft was much slower. No evasive action was taken by my aircraft or by the other aircraft. I thought I was maintaining an effective scan for conflicts. The fact that I was engaged in a functional check flight and therefore was dividing my attention inside and outside was a factor in this event. Also, the coloration of the cessna seemed to blend with terrain (gold and white or tan and white). Another factor was the speed differential of the aircraft (my rapid overtake). I thought I gave collision avoidance the highest priority. From now on, collision avoidance will be a conscious effort any time I operate in VMC! Using all techniques available.

Original NASA ASRS Text

Title: PLT OF AN L39 MIL JET TRAINER HAS NMAC.

Narrative: DURING DSCNT FOR INITIAL APCH TO STS, I PASSED A C172 (OR C152) ON ITS R SIDE. I WAS INDICATING APPROX 240 KTS, THE OTHER ACFT WAS MUCH SLOWER. NO EVASIVE ACTION WAS TAKEN BY MY ACFT OR BY THE OTHER ACFT. I THOUGHT I WAS MAINTAINING AN EFFECTIVE SCAN FOR CONFLICTS. THE FACT THAT I WAS ENGAGED IN A FUNCTIONAL CHK FLT AND THEREFORE WAS DIVIDING MY ATTN INSIDE AND OUTSIDE WAS A FACTOR IN THIS EVENT. ALSO, THE COLORATION OF THE CESSNA SEEMED TO BLEND WITH TERRAIN (GOLD AND WHITE OR TAN AND WHITE). ANOTHER FACTOR WAS THE SPD DIFFERENTIAL OF THE ACFT (MY RAPID OVERTAKE). I THOUGHT I GAVE COLLISION AVOIDANCE THE HIGHEST PRIORITY. FROM NOW ON, COLLISION AVOIDANCE WILL BE A CONSCIOUS EFFORT ANY TIME I OPERATE IN VMC! USING ALL TECHNIQUES AVAILABLE.

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.