Bonanza 36
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 50; Flight Crew Total 1100; Flight Crew Type 700
Other / Unknown
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed As Precaution; General Declared Emergency; General Maintenance Action
Aircraft
While on an IFR flight; flying at 7;000 feet; I heard a muffled bang; heard increased exhaust noise; and smelled exhaust fumes. Fearing a compromised turbocharger or exhaust system and the potential for fire; I declared an emergency to ATC and asked for vectors to the nearest airport (4 miles).  While descending; I asked ATC for the Tower radio frequency twice but they did not reply. After landing; it was quite apparent that they knew I was coming as the fire trucks were easily visible to me. I worried about not having contact with the Tower but thought that ATC figured I was busy enough putting the airplane down successfully. The muffled bang was the fuel sump door opening in flight. It was repaired and I was on my way home the same day. Great work on ATC's part!
BE36 pilot reports a muffled bang during cruise at 7;000 feet followed by increased exhaust noise and the smell of exhaust fumes. Fearing a compromised exhaust system; an emergency is declared and vectors requested to the nearest suitable airport. Post flight revealed the fuel sump door had opened in flight.