I am getting a fine rubber dust which seems to be blown into my lap and below my seat while in flight. I have checked everything where if might be coming from but nothing is obvious. Does anyone have any ideas as to what it might be. I think it's some kind of impeller or something like that. Don't have any idea besides that. My heater was overhauled 2 annuals ago and I frankly don't use it, will probably use it this winter. Any ideas would be appreciated,
Jim