Bonanza 35
Flight Crew Private; Flight Crew Instrument
Flight Crew Last 90 Days 17; Flight Crew Total 585; Flight Crew Type 395
Confusion; Communication Breakdown
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Human Factors; Airport; Environment - Non Weather Related
I was coming into HLN from the East on V2 at 11;000 feet MSL on an IFR flight plan. The conditions were IMC. At about 7 miles I broke out and had the airport in sight. The airport field elevation is 3;873 feet. I thought that I had clearance to descend to 9;000 feet; but that was not so.
A BE-35 pilot on an IFR flight plan descended below his cleared altitude inbound to HLN.