Narrative:

Generator failed enroute. An unknown battery charge was remaining. I contacted tower for landing and requested an overhead approach. Tower was busy and told me to expect the straight-in approach. I repeated I needed the overhead and tower told me I had to do a straight-in. I told the tower I would have to [request priority handling] to get the overhead.the overhead in this type aircraft is standard operating procedure for safety reasons. Rarely; I will accept a standard pattern; but only if everything is working properly. In this case I already had a failure and did not want to compound the situation. Given an electrical failure the following systems are impacted. Fuel boost pump; emergency fuel system (in the event of a carburetor failure); all coolant and oil temperature readings; coolant and oil door actuators; all warning lights in the cockpit; all avionics including radios. Given I already had one failure and not knowing when the battery may fail; a straight-in approach is a high-power; low-energy approach; meaning any hiccup in another system would most likely result in an off-field landing with potential property damage and possible injury to persons on the ground. The overhead provides an additional measure of safety by ensuring a higher energy state over the field. The overhead also is the fastest way to get on the ground; thus eliminating traffic delays in most any environment. I should have been able to work into the traffic pattern and do the overhead; but the controller's lack of knowledge of the safety aspect of the overhead pattern required me to [request priority handling] to deviate from his instruction to ensure as much of a safety margin as possible. The controller overreacted to the situation; which should have been a non-event.

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Original NASA ASRS Text

Title: P51 pilot reported a generator failure enroute that required him to request priority handling and make a precautionary landing.

Narrative: Generator failed enroute. An unknown battery charge was remaining. I contacted Tower for landing and requested an overhead approach. Tower was busy and told me to expect the straight-in approach. I repeated I needed the overhead and Tower told me I had to do a straight-in. I told the Tower I would have to [request priority handling] to get the overhead.The overhead in this type aircraft is standard operating procedure for safety reasons. Rarely; I will accept a standard pattern; but only if everything is working properly. In this case I already had a failure and did not want to compound the situation. Given an electrical failure the following systems are impacted. Fuel boost pump; emergency fuel system (in the event of a carburetor failure); all coolant and oil temperature readings; coolant and oil door actuators; all warning lights in the cockpit; all avionics including radios. Given I already had one failure and not knowing when the battery may fail; a straight-in approach is a high-power; low-energy approach; meaning any hiccup in another system would most likely result in an off-field landing with potential property damage and possible injury to persons on the ground. The overhead provides an additional measure of safety by ensuring a higher energy state over the field. The overhead also is the fastest way to get on the ground; thus eliminating traffic delays in most any environment. I should have been able to work into the traffic pattern and do the overhead; but the controller's lack of knowledge of the safety aspect of the overhead pattern required me to [request priority handling] to deviate from his instruction to ensure as much of a safety margin as possible. The controller overreacted to the situation; which should have been a non-event.

Data retrieved from NASA's ASRS site 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.