Caravan 208B
Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Flight Crew Last 90 Days 160; Flight Crew Total 650; Flight Crew Type 400
Training / Qualification; Communication Breakdown; Physiological - Other
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown; Inflight Event / Encounter Weather / Turbulence
General None Reported / Taken
Equipment / Tooling; Human Factors; Procedure; Weather
On our return flight the Captain filed an IFR flight plan. Before the flight the Captain gave no briefing; but merely said we were going a little high; and directed me to brief the passengers. I didn't know how high we were going so I just prepared the masks and briefed the passengers on how to use them and when; but none agreed to use them. After we departed the Captain told me he filed for 14;000 FT and we went on oxygen passing 10;000 FT. Once we reached cruise altitude I did ask the passengers to put the oxygen masks on but; again; no one did so. We later asked Center for higher due to clouds at our altitude and we did pickup a lot of ice at 16;000 FT MSL around 50 NM from our destination. Later; Center asked us to go higher for traffic and at some point; we were at 19;000 FT [FL190] for about 13 minutes; then we got cleared for lower. At all times we did ask the passengers to use oxygen masks [but none did so]. After we landed we asked everyone how they felt and no one complained or commented. I believe what caused the problem was there was no communication with the Captain (who is new) and I didn't confirm what he meant by 'going high' so I could prepare the oxygen masks and place them in each seatback pocket for easy access by the passengers. The masks are normally stored in the front seat area in a plastic bag.
Poor communication between the Captain; the First Officer (reporter); and the passengers aboard a commercial C208B resulted in the passengers not donning provided oxygen masks despite operating at altitudes as high as FL190 due to weather.