Date: 201503
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: Mixed
Weather elements / visibility: Fog; Rain; Haze / Smoke; 1
Light: Daylight
Aircraft: Helicopter
Operator: Air Taxi
Operating under: Part 135
Flight plan: VFR
Mission: Ambulance
Flight phase: Cruise
Airspace: Class E ZZZ; Class G ZZZ1
ATC / advisory: Center ZZZ
Reporter organization: Air Taxi
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Human factors: Confusion; Communication Breakdown; Distraction; Workload; Situational Awareness; Training / Qualification
Anomaly: Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter VFR In IMC
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Diverted; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Contributing factors: Procedure; Weather; Human Factors
Primary problem: Weather

Narrative: We got a call mid afternoon transport. The weather had been below minimums for most of the day but there had been a gradual improving trend; though slower than originally forecast.  I explained that to the West ZZZ was preferred and crew said they'd need more information about our task because; depending its importance; it may prove necessary to go East ZZZ1.  We chose to go and make the decision on the pad; local weather was greater than 2000 feet and 10 miles. ZZZ was reporting 1500 feet and 10 statute miles. ZZZ2 was reporting 1300 feet and 10 and ZZZ1 was 1000 feet and 8. ZZZ1; our closest AWOS showed 2400 feet and greater than 6 statute miles.  Temp / Dewpoint spreads were close but steady. ZZZ1's forecast was for it to go to 1500 feet and remain there until after our return. At the pad; the Crew determined we needed to go to ZZZ3. Ceilings were 2000 feet in the East area until about 15 minutes into flight. Further ahead ceilings looked to be 1000 feet and this was expected. Ahead there were very large controlled brush fires that reduced visibility. Passing the fires; the ceilings rapidly started coming down and it was apparent the visibility was as well. Visibility below the overcast had been nearly 10 miles and I expected that once past the fires but the smoke only obscured the lower ceilings and diminished visibility on the far side. I had descended to remain in the clear and hit my Enroute Decision Point so I explained to the crew that we wouldn't be able to continue. I started looking for an appropriate landing zone and the closest was a private airfield that I was familiar with. It looked like I could remain in the clear. Further South ceilings looked much lower. I considered a 180 turn but it looked like it was coming down all around us and the options behind us were fewer. Shortly after; I could not remain clear of clouds and maintain a safe altitude.  It happened very quickly.  Prior to experiencing it myself; I never understood how someone could fly inadvertently into IMC during the daytime. I confirmed to the crew that I was on instruments and began a slow climb and turned slightly right to the South since there was a 1200 feet AGL tower ahead. I completed the company IMC checklist. I then hit the panic button (sends a distress signal to our communications center and provides more frequent position information to company communications center controllers via satellite) and got a frequency; for ATC Center. Our Operational Control Center (OCC) controller recommended a nearby airport and the RNAV APCH there. I reached Center. I advised that I was inadvertent IMC approximately with my location and requested vectors to known VMC.  Center directed me to climb to 2200; and to expect higher; because he had another plane in the area at 3000 feet.  Center then put me on a discrete squawk and requested my intentions. I asked for vectors to the IAF and explained that I would have my OCC talk me through the procedure. He began vectors to the IAF for the RNAV GPS.  Center asked me that since I was now IFR with them if I wanted to cancel the emergency but I explained that we were not IFR certified and that I needed to retain my emergency status. Once established on the Final Approach Course; Center acknowledged that I would be talking to OCC for the procedure and asked me to write down a phone number to contact them when we were safe on deck. The crew advised ready to copy and I prompted Center but they may have gotten busy with other aircraft and never actually provided the phone number. OCC monitored my progress to the FAF and provided all instrument approach procedure information.  An uneventful landing.




Synopsis: A non IFR rated helicopter pilot describes his experience after inadvertently entering IMC; then requesting ATC assistance for an IMC diversion to a nearby airport.