Date: 201505
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Cloudy; Turbulence; 9
Light: Daylight
Aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Climb
Airspace: Class E ZZZ
Second aircraft: Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Flight Crew Commercial
Human factors: Communication Breakdown; Distraction; Situational Awareness
Anomaly: Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Procedure; Environment - Non Weather Related; Human Factors
Primary problem: Human Factors

Narrative: Weather (low clouds) had made the originally planned trip to my home airport via the most direct airway not possible. A coastal route was chosen due to better weather. This route was planned and the weather was discussed with weather brief services.The new planned route was direct with deviations as clouds and terrain allowed for a shorter trip. Departure [occurred] without issue; and into a normal climb to 7;500 feet MSL due West towards the coastline to avoid mountainous terrain to the North. Plan to turn as soon as terrain and clouds allowed. Remained CTAF until greater than 5NM from the airport; then switched to [local] Approach. Monitored but did not plan to contact [approach] until within 20NM; to allow proper communication with facility and to ensure we were near their airspace. Without certainty but believed to be in the vicinity near the edge of the Class E airspace; climbing through approximately 4;500 feet MSL: as we were climbing Westbound; a single engine; low-wing aircraft heading approximately South-Eastbound crossed above and convergent with our flight-path. Closest distance is believed to be approximately 300 feet. Our landing light was on as well as our strobe light; the other aircraft did not appear to have any lights visible. We were monitoring but not in communication Approach. Factors that contributed were the nature of this airspace being very congested and busy; but we were aware so were heads up and looking for traffic (pilot and passenger). The nature of this airspace has aircraft ascending and descending concurrently; increasing the chances for converging aircraft. Passenger was first to notice the traffic so having two people looking probably helped the situation. Upon identification of the traffic; the passenger notified the pilot immediately and it was determined that no action was required to avoid collision. Not being in communication with the relevant ATC may have contributed as they may have notified both airplanes of our mutual proximity and closing paths. Landing and/or strobe lights may have also helped in seeing the traffic sooner. The other aircraft appeared to be in a slow descent; so may not have had adequate forward visibility to see our aircraft. Following the airway would have had us on a similar flight path so may not have helped; if we'd been using that airway. Using a VFR Flight Plan may have helped in notifying the local ATC facilities of our intention to use the airspace; but that information may have been too course to allow for the fine separation needed in this situation. Though the weather reporting stations South [departure airport] do not indicate clouds; clouds (approximately FEW coverage) were located above the mountainous terrain to the North. This is the direction from which the traffic was flying.




Synopsis: A pilot reported a near miss in VMC with another aircraft in Class E; but not communicating with TRACON.