Narrative:

I departure camarillo on an IFR flight plan to las vegas. Center was not responding to my request for the IFR clearance, so we departed under VFR conditions, and planned to pick up the clearance once airborne. The WX briefing stated that good VFR conditions prevailed, so a VFR departure was acceptable. However, once airborne conditions appeared to have deteriorated. While maintaining VFR, we attempted to obtain the IFR clearance, but center delayed it. Radar contact was not established initially, and I stated we would be unable to maintain VFR in the climb. At this point, center questioned whether we had received a WX briefing. By the time we did receive the clearance, we were in an area of VFR, and requested a VFR climb on course. Apparently, a marine layer moved in along the coast which was unforecast and not easily detectable at night. Furthermore, had we not proceeded to an area of good WX, the initial flight plan routing would have led us into an area of marginal VFR at night in mountainous terrain. In summary, an IFR clearance should be obtainable prior to departure, or expeditiously under similar conditions in flight.

Related reports:

Google
 

Original NASA ASRS Text

Title: STUDENT AND INSTRUCTOR DEPART CMA FOR A NIGHT IFR FLT TO LAS AND EXPERIENCE A DELAY RECEIVING AN IFR CLRNC WHILE ENCOUNTERING DETERIORATING WX CONDITIONS.

Narrative: I DEP CAMARILLO ON AN IFR FLT PLAN TO LAS VEGAS. CTR WAS NOT RESPONDING TO MY REQUEST FOR THE IFR CLRNC, SO WE DEPARTED UNDER VFR CONDITIONS, AND PLANNED TO PICK UP THE CLRNC ONCE AIRBORNE. THE WX BRIEFING STATED THAT GOOD VFR CONDITIONS PREVAILED, SO A VFR DEP WAS ACCEPTABLE. HOWEVER, ONCE AIRBORNE CONDITIONS APPEARED TO HAVE DETERIORATED. WHILE MAINTAINING VFR, WE ATTEMPTED TO OBTAIN THE IFR CLRNC, BUT CTR DELAYED IT. RADAR CONTACT WAS NOT ESTABLISHED INITIALLY, AND I STATED WE WOULD BE UNABLE TO MAINTAIN VFR IN THE CLB. AT THIS POINT, CTR QUESTIONED WHETHER WE HAD RECEIVED A WX BRIEFING. BY THE TIME WE DID RECEIVE THE CLRNC, WE WERE IN AN AREA OF VFR, AND REQUESTED A VFR CLB ON COURSE. APPARENTLY, A MARINE LAYER MOVED IN ALONG THE COAST WHICH WAS UNFORECAST AND NOT EASILY DETECTABLE AT NIGHT. FURTHERMORE, HAD WE NOT PROCEEDED TO AN AREA OF GOOD WX, THE INITIAL FLT PLAN ROUTING WOULD HAVE LED US INTO AN AREA OF MARGINAL VFR AT NIGHT IN MOUNTAINOUS TERRAIN. IN SUMMARY, AN IFR CLRNC SHOULD BE OBTAINABLE PRIOR TO DEP, OR EXPEDITIOUSLY UNDER SIMILAR CONDITIONS IN FLT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.