Cessna 310/T310C
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 30; Flight Crew Total 430; Flight Crew Type 50
ATC Issue All Types; Conflict NMAC
General None Reported / Taken
Human Factors; Procedure
We were in cruise at 9000 feet on an IFR flight plan. We were talking to Gray approach at the time. I recently had ADS-B installed in my aircraft and I got a traffic target on my Garmin 530W. It looked like it could be a conflict. I called Gray approach and asked if they had target at my 12 o'clock. Took a little [time] to respond. My wife and I were both looking for the target. It got within 200 ft of our altitude and was pretty much head on. I was debating turning but I wanted to get a visual if I could to make a better decision. I was going 200 mph or so and the target was going like 240 knots according to my iPad so not much time to figure it out. I had my 530w traffic page set at 6 miles for this exact reason to catch them sooner. We got a visual on the target probably 1.5 miles out. They went under our right wing. We were south bound they were north bound. When they passed ADS-B was alerting 300 ft separation but it had gotten to 200 ft.I complained to Gray approach told them that was way closer than I liked. I am on an IFR flight plan for a reason; to get some more eyeballs looking out for me. The controller kinda blew it off and almost immediately handed me off to Houston Center. Even though I did not have to make an altitude change; I was aware of the situation and ready to do so because of ADS-B traffic. Maybe the controllers were preoccupied or they were shorthanded or busy handing us off. Regardless; way too close for me and my family.
C310 pilot reported an NMAC at 9;000 FT while on an IFR flight.