Small Aircraft
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 5; Flight Crew Total 19000; Flight Crew Type 270
Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict NMAC
General None Reported / Taken
Human Factors; Procedure
A temporary tower was in use. I noticed the flight of 9 on a downwind and I assumed they were preparing to perform a fly-by of Runway XY. I was cleared for takeoff behind another flight of 3 aircraft. I did not see the location of the previous flight of 9; and departed as instructed. I continued runway heading as I watched the previously departed flight of three and as I climbed through about 1;000 feet AGL I was passed on my left side very closely by the flight of 9. At no time did the Tower advise either me or the flight of 9 of the traffic.In retrospect; this was sort of a perfect storm for a conflict. My aircraft is slow (70 KTS); but climbs very rapidly (1;500+ FPM). The flight was probably cruising about 140 KTS and wouldn't have expected slower traffic to suddenly climb into their flight path. I can't see traffic above and behind me; especially with 70 KTS of overtake.Tower is manned by volunteers who do a superb job of handling lots of traffic; but unfamiliarity and distraction caused a loss of situational awareness. I would suggest the following procedural change and other fly-ins where there is a fly-by pattern that lies over the top of the departing runway: That departing traffic be restricted in altitude on departure; say 800 AGL until clear of the airport and fly-by traffic be restricted to 1;300 AGL while overflying the runway.
Pilot reported departing airport during fly-in and was overtaken by unreported fly-by aircraft.