Skyhawk 172/Cutlass 172
Flight Crew Private
Flight Crew Last 90 Days 63; Flight Crew Total 178; Flight Crew Type 132
Situational Awareness
Conflict NMAC
Flight Crew Took Evasive Action
Human Factors
[I was] on Flight Following with ATC Pt Mugu; [vicinity of FIM]; 6500ft; westbound. [I was] acting as PIC; with another pilot (student) in right seat. Received warning 'traffic at 1 o'clock; 6500 feet; heading northeast; type unknown'. As traffic was visible; and not on intersecting course; reply was made 'Traffic in sight; no factor'.Soon thereafter; the unknown traffic was observed to change course on a right turn; finishing turn on a direct intersection course with our aircraft; at the same altitude. The incoming aircraft had strobe lights active; so the intersecting course was very clear. Evasive action was taken with a standard rate turn to the right.The incoming aircraft was observed to initiate a left turn; thereby remaining on intersecting course. At this point I increased bank of turn; pulled power and initiated a steep descent. Incoming aircraft was now observed to be on a shallow descent; and very nearly intersecting our course despite evasive actions. It is my judgment that if I had not initiated a steep descent; collision was probable. Estimate that the incoming aircraft passed <500 feet behind; and +/- 200 feet of our altitude. GPS data onboard shows that we descended 300 feet in 15 seconds and altered course by 60deg.Incoming aircraft observed as probable to be a twin engine; low wing General Aviation type aircraft. Original course and altitude was resumed; and finally ATC was informed that traffic became a factor and evasive actions were taken.Contributing Factors:Both aircraft navigating over a TFR (Surface to 5500 feet).Due to TFR and recent high winds; minimal GA traffic expected to be operating in the airspaceIncoming aircraft was (I understand) not on Flight Following and not in contact with ATC.
C172 pilot reported a NMAC with another light aircraft in vicinity of FIM VOR.