Narrative:

The bonanza BE35 we were flying had an intermittent alternator on the ground during run-up for the return flight. During this run-up; the alternator did not pick up any loads imposed on the electrical system; but after several resets/recycles; appeared to correct itself and pick up the load of lights; strobes; etc placed on it. Out of a precaution; we (myself and pilot rated passenger); flew back with the gear in the down position. Shortly after takeoff; the alternator failed again. The alternator circuit breaker had not tripped; so an over voltage condition was not suspected. I turned off the electrical system (battery and alternator) and made the rest of the return trip (about 1.5 hours) without the electrical system to preserve the battery for the final 5-10 minutes of flight; which would occur close to sunset. My passenger called the tower on his cell phone to let the tower know to expect our arrival in case we had no battery power remaining upon arrival. The tower told us to give them a call if possible on the radio; but that they would be expecting our arrival. At sunset; and within 10 miles of the airport we switched on the electrical system with battery only; activating the transponder; one radio; nav lights; beacon; landing and anti-collision lights. We called tower and received clearance and landed without incident and with battery power remaining. On the ground; we were followed to our hangar by the airport fire truck who told us that the even though I (the PIC) had not declared an emergency; the tower had done so for us. They asked for my name at that point for their incident file. Our airplane (owned by a club); had apparently had the exact same alternator failure incident the previous day; and the tower was annoyed to have to deal with this type of incident 2 days in a row; and was the reason they elevated my incident to an 'emergency'. I had received no notification of this squawk! While I feel that I was in compliance with the far's; upon reflection; an intermediate landing site should have been more strongly considered. I had a few airports that were candidates; but was weighing the ability to troubleshoot the problem/available mechanics at a strange airport; vs. Returning to home base where I knew the problem could be diagnosed. Ultimately; I decided that the return flight to ZZZ could be conducted safely given the day VFR condition; some available battery power; cell phone communication with the tower; pilot rated passenger to assist; flashlights in the cockpit if needed and risk involved in going to a non-towered field with a potentially failing electrical system.

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Original NASA ASRS Text

Title: BE35 pilot experienced alternator failure shortly after takeoff enroute to home base and elected to continue with the battery and alternator turned off and the gear extended. After the battery was turned on for landing an uneventful landing ensued at destination; with radio communication.

Narrative: The Bonanza BE35 we were flying had an intermittent alternator on the ground during run-up for the return flight. During this run-up; the alternator did not pick up any loads imposed on the electrical system; but after several resets/recycles; appeared to correct itself and pick up the load of lights; strobes; etc placed on it. Out of a precaution; we (myself and pilot rated passenger); flew back with the gear in the down position. Shortly after takeoff; the alternator failed again. The alternator circuit breaker had not tripped; so an over voltage condition was not suspected. I turned off the electrical system (battery and alternator) and made the rest of the return trip (about 1.5 hours) without the electrical system to preserve the battery for the final 5-10 minutes of flight; which would occur close to sunset. My passenger called the Tower on his cell phone to let the Tower know to expect our arrival in case we had no battery power remaining upon arrival. The Tower told us to give them a call if possible on the radio; but that they would be expecting our arrival. At sunset; and within 10 miles of the airport we switched on the electrical system with battery only; activating the transponder; one radio; nav lights; beacon; landing and anti-collision lights. We called Tower and received clearance and landed without incident and with battery power remaining. On the ground; we were followed to our hangar by the airport fire truck who told us that the even though I (the PIC) had not declared an emergency; the Tower had done so for us. They asked for my name at that point for their incident file. Our airplane (owned by a club); had apparently had the exact same alternator failure incident the previous day; and the tower was annoyed to have to deal with this type of incident 2 days in a row; and was the reason they elevated my incident to an 'emergency'. I had received no notification of this squawk! While I feel that I was in compliance with the FAR's; upon reflection; an intermediate landing site should have been more strongly considered. I had a few airports that were candidates; but was weighing the ability to troubleshoot the problem/available mechanics at a strange airport; vs. returning to home base where I knew the problem could be diagnosed. Ultimately; I decided that the return flight to ZZZ could be conducted safely given the day VFR condition; some available battery power; cell phone communication with the Tower; pilot rated passenger to assist; flashlights in the cockpit if needed and risk involved in going to a non-towered field with a potentially failing electrical system.

Data retrieved from NASA's ASRS site as of April 2012 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.