Date: 201509
Local time of day: 1201-1800
Location: DWA.Airport, CA
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Cessna 210 Centurion / Turbo Centurion 210C; 210D
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Cruise
Airspace: Class E SUU
ATC / advisory: TRACON SUU
Second aircraft: Skylane 182/RG Turbo Skylane/RG
Reporter organization: Personal
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Private
Human factors: Situational Awareness
Second reporter function: Single Pilot; Pilot Flying
Anomaly: ATC Issue All Types; Conflict NMAC
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Procedure
Primary problem: Ambiguous

Narrative: [I] was flying VFR to [my] final destination. After departing; [I] requested and was provided flight following. After transitioning into Travis Approach controlled airspace - communicating with Travis Approach; [I] was handed off to [another] Travis Approach [controller]. [I] was approximately 20 miles southwest of Yolo County airport; Travis advised the 'jump area' off Yolo to be active and advised a turn 20 degrees to the left from 335 to 315. Then; continuing in flight and when [I] was directly west of Yolo; [I] made a request to turn back on course to [my destination]; which was then 336.Shortly thereafter; Travis Approach provided a traffic advisory indicating traffic was one (or two miles - don't recall for sure) at [my] 10 o'clock position; heading the same direction; at the same altitude. [I] spotted traffic and advised traffic was in sight. At that point; traffic appeared to be at an altitude 50-100 feet lower than [me]; and at least one mile away at the 10; moving to 9 o'clock position. As [I] was moving from the other traffic at the 10 o'clock position to the 9 o'clock position; traffic had moved closer and was now directly off the wing at approximately 3/8 to 1/2 miles.While [I] was passing and the other traffic was moving from [my] 9 o'clock position to 7-8 o'clock position; traffic continued to move closer and [I] turned approximately 10 degrees to the right. Traffic passed behind [my] position from 7-6-5 o'clock positions and appeared to pass somewhere between 300-500 feet in horizontal distance behind [me] and about 50-100 feet vertical distance below [me].Traffic then reported to Travis Approach the proximity and closeness; and indicated feeling the wake of [my aircraft]. Travis Approach didn't reply to [my] knowledge; as Travis handed [me] off to Oakland Center. [I] reported occurrence to Oakland Center. Traffic has also been handed off to Oakland Center and heard the explanation and discussion between Oakland Center and [me]; and essentially acknowledged concurrence with [me]. Oakland Center made both [me] and traffic (reported as a 182) aware of Travis Approach's telephone number to file a report; and indicated Travis Approach is a training program for ATC and reports help enhance safety. Both aircraft indicated they would call and make a report with Travis Approach; and also file [a safety report]. [I] attempted to call the number and received an error message.It was stated in the discussion with Oakland Control that [I] was heading 336 and [the 182] was heading 351 at first advisory. The proximity circumstance could have likely been avoided if Travis Approach had not indicated traffic was heading in the same direction when they weren't; but instead were slightly converging; and if Travis Approach had advised either or both aircraft to turn to headings away from the slowly converging headings.


Second narrative: I was cruising at 8;500 feet at 130 KTS with a ground track of 351. I was VFR with flight following from Travis North sector. I was near the Williams VOR and almost to the point where I expected Travis would hand me off to Oakland Center.I heard Travis give a traffic call of traffic at 12 o'clock; 2 miles; same direction; to another aircraft. Immediately afterward I got a call for traffic at 6 o'clock; same direction; 8;700 feet. I realized that the earlier call was about me. I asked Travis if the aircraft was overtaking and the response was yes; Centurion at 160 KTS. I assumed that Travis was tracking both of us and the other pilot could see me.10-15 seconds later a green and white Cessna flashed by my right side at exactly my altitude and I estimate at most 100-200 feet away. I have formation flying experience and am confident in my estimate of the distance. It crossed in front of me no more about 300 feet away. I flew through the wake and felt it strongly.I called Travis and reported the near miss and that I had flown through a strong wake. My recollection is that Travis' only response was to hand me off to Oakland Center. He had also just handed the other aircraft off.I switched frequencies and the other pilot was already excitedly talking with Oakland. The controller said that when we were handed to her our data blocks were completely overlapping so at first she thought we were flying formation.The controller talked with both of us for some time. I believe she had handed off her other traffic to someone else. The other aircraft was a Cessna Centurion. He said he was tracking about 336 at an indicated 8;700 feet and 160 KTS. I was tracking 351 at an indicated 8;500 and 130 KTS. He said that the controller had noted traffic and said we were traveling in the same direction at approximately the same altitude. He assumed that he would pass cleanly or the controller would have told him to divert. He said that he only saw me at the very last second and had just started to divert when he passed me. I told both the other pilot and controller that I pretty much agreed with his statements. Our recollections of the communications with Travis were also very close.I called Travis and talked with someone in ATC. I didn't get his name. He told me to expect a call from his boss. I haven't heard from him.I believe that the other aircraft was probably on auto-pilot so the pilot thought there was no conflict when he was told we were heading in the same direction so he was not looking outside. I clearly had the right of way but that doesn't help much if someone takes your wing off.I believe the primary causes of this very close call were:(1) Poor communications from Travis.(2) Travis failure to provide diversion instructions to either aircraft.(3) The pilot of [the other aircraft] failure to see and avoid when overtaking.


Synopsis: Two pilots of single engine aircraft reported an NMAC with each other while in Travis Approach Control airspace.