Amateur/Home Built/Experimental
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 17; Flight Crew Total 1773; Flight Crew Type 1380
Situational Awareness
Conflict NMAC
General None Reported / Taken
Human Factors
I was practicing RNAV approaches to GIF's Rwy 11 in VFR conditions. On the RNAV approach at 10 nm from the airport a Cessna 172 flew over me and immediately behind me.  I was watching my ADSB in and the approach was clear. The aircraft 'popped up' onto the ADSB in display approx 2 seconds before it passed 400 feet above and approx 50 feet aft. ADSB data was used to determine the 400 foot separation.
Pilot of a home built aircraft reported an NMAC with another light aircraft in the pattern at GIF airport.