M20 pilot reported a loss of electrical power and diversion to an airport outside of the mode C veil...

Attributes
ACN	1492318
Time
Date	201710
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	M-20 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	VFR
Component
Aircraft Component	Electrical Power
Person 1
Function	Pilot Flying
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 177 Flight Crew Type 90
Events
Anomaly	Aircraft Equipment Problem Less Severe Flight Deck / Cabin / Aircraft Event Other / Unknown

Narrative:

Flight conditions VFR. [In cruise]; electrical problems developed and GPS intermittently lost power. PIC made the decision to return to ZZZ. Enroute to ZZZ; GPS/primary comms lost all power. Comm 2 was activated. Further on; comm 2 lost power; and transponder eventually lost power. Decision was made to land at ZZZ1 since it was apparent electrical problems were developing quickly. Flight did not continue to ZZZ because it was fully within the mode-C veil; and transponder had lost power. ZZZ1 was chosen because it was closest and partially outside the mode-C area. As flight progressed; aircraft lost lights and on-board intercom; creating an immediate need to land and possibly quasi-emergency situation. Flight landed safely at ZZZ1 after pilot controlled runway lighting was successfully activated by a hand held transceiver. A non-flying pilot contacted the TRACON on the ground and requested permission to enter the mode-C area without a transponder; in the event the aircraft could be safely restarted and flown to ZZZ. Permission was granted by TRACON; though the controller seemed indifferent provided the aircraft stayed outside (under) the class B airspace. The aircraft could not be restarted and flown; and was left at ZZZ1 for repair.

Original NASA ASRS Text

Title: M20 pilot reported a loss of electrical power and diversion to an airport outside of the Mode C veil.

Narrative: Flight conditions VFR. [In cruise]; electrical problems developed and GPS intermittently lost power. PIC made the decision to return to ZZZ. Enroute to ZZZ; GPS/Primary Comms lost all power. Comm 2 was activated. Further on; Comm 2 lost power; and transponder eventually lost power. Decision was made to land at ZZZ1 since it was apparent electrical problems were developing quickly. Flight did not continue to ZZZ because it was fully within the Mode-C veil; and transponder had lost power. ZZZ1 was chosen because it was closest and partially outside the Mode-C area. As flight progressed; aircraft lost lights and on-board intercom; creating an immediate need to land and possibly quasi-emergency situation. Flight landed safely at ZZZ1 after pilot controlled runway lighting was successfully activated by a hand held transceiver. A non-flying pilot contacted the TRACON on the ground and requested permission to enter the Mode-C area without a transponder; in the event the aircraft could be safely restarted and flown to ZZZ. Permission was granted by TRACON; though the controller seemed indifferent provided the aircraft stayed outside (under) the Class B airspace. The aircraft could not be restarted and flown; and was left at ZZZ1 for repair.

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.