Skylane 182/RG Turbo Skylane/RG
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 33; Flight Crew Total 1518; Flight Crew Type 300
Communication Breakdown; Situational Awareness
Conflict NMAC
Flight Crew Took Evasive Action
Procedure; Human Factors
I was on descent from 3;500 feet; preparing to land at ZZZ. Was on CTAF freq; announced intentions; location; etc. Another aircraft was leaving the area in the direction I was flying in from; so I was very carefully scanning the sky in the direction of the airport; dedicating most of my scan time on that area (my 9-12 o'clock); since i knew someone from there was headed at the precise location I was at.Looked down at my checklist (on iPad) and saw it was on the wrong page. Flipped it to the right page. This took approx 10 sec. When i looked back up; a plane was crossing ahead of me; right to left; same altitude; climbing; approx 300 feet away. Seems that as I was descending on about a 060 heading; it was climbing and turning left slowly; causing it to be out of my sight until it got close to my altitude (visibility down and right is rather bad in a C-182 since the door obscures the view). It was not the plane I was looking from from ZZZ; just some other plane that happened to be in the area and not on the CTAF freq.We passed each other around 300 feet away. I turned right to accelerate this. The other plane did not change course and I suspect they never saw me. I do not remember the full tail number of the aircraft. It was a Cessna single-engine with struts. 172 or 182; I suspect.My main issues here: I concentrated too much of my scan on an area of the sky where I expected to see a plane; and i took my eyes off the sky for ten seconds to fumble with an iPad.Other aircraft main issues: visibility UP in a Cessna is much better than DOWN (plexiglass windshield vs aluminum floor/doors). They should have also been looking - my plane should have been in their view for a long time.Corrective actions: switch back to paper checklists - they cannot flip to the wrong page and thus waste valuable eye-time.
Pilot reported a near miss with another aircraft and took evasive action.