Narrative:

On a december night 2010; I received a mobile alert that the rental aircraft filed for ZZZ earlier had diverted to ZZZ1 due to experiencing electrical problems on an instrument flight. Since I was going to be out of town for six weeks; I contacted the pilot to inquire. Knowing this pilot's history of safety and attention to paperwork detail that is necessary in this industry; I asked if he would take charge of getting the plane repaired.34 days and two maintenance facilities later; the electrical system was tracked down; repaired; signed-off and [the aircraft] is back in the hangar. However; after being briefed on the process; I found it fascinating; but also realized that even though I had an independent chief instructor in charge of insuring the legal endorsements and documentations were kept up; ultimately I need to be more involved in assuring these things are done. This was a wake-up call for me. The rest of this report is a description of the 'history-of-interest' during the troubleshooting phase of the electrical repair and the information that was uncovered. This is the written version from [discussions with] the pilot-in-charge: after flying aircraft to an away-from-base maintenance facility and extensively studying the logbooks for the aircraft; which was rented from a local flight school; it was discovered that there were a number of omitted logbook entries and other missing or incomplete paperwork for the aircraft. The aircraft was not airworthy.an aileron was re-skinned and re-painted; with an FAA form-337 only partially being completed and without a copy being forwarded to the local FSDO. Additionally; there was no logbook record of the repaired aileron being removed or for it being reinstalled on the aircraft; nor for the aileron's balance being checked after painting; though the repairs were clearly accomplished.in the course of providing background information to the repair facility; we investigated a number of components in the aircraft's charging system which had been burning-out voltage regulators; circuit breakers; and alternators on a regular basis for over a year. We discovered that the alternator installed in the aircraft was of twice the capacity of that approved for the aircraft. The over-sized alternator was; according to the logbook; first installed when the aircraft's engine was replaced with an overhauled engine at repair station X in 2009 -- when the alternator problems began (determined only with the benefit of hindsight). I do not believe the erroneous installation was intentional; though it has been costly; and apparently dangerous; for everyone involved.subsequent replacements; accomplished by numerous [repair] facilities; merely replaced the part number of the removed component without verifying its approval for the aircraft's serial number. Doing further research we came to the conclusion that although the particular oversized alternator was not approved for that specific year airworthiness directive (ad) serial number of aircraft and because of extensive avionics upgrades; the addition of a heated pitot tube; ad for the addition of anti-collision strobes; all done in 2005; an alternator of additional capacity would actually be required to maintain sufficient electrical power to the aircraft's electrical busses during a maximum load condition -- especially likely in IMC.it was also discovered that the alternator field breaker was wrong by any criteria used. The alternator amp-breaker was undersized for the alternator output; the alternator wiring was grossly undersized for the output capacity of the installed unit; and the ammeter (now mysteriously shunted) was not able to meter the rated capacity of the installed alternator. Though; thankfully the only damages were monetary; clearly such an installation was a fire hazard and not airworthy.unapproved methods; techniques; and practices were evidently used to accomplish some of the upgrades performed in 2005; and this is an underlying factor in the ongoing maintenance issues this aircraft has experienced. All discrepancies on the aircraft have been satisfactorily corrected; the charging system has been completely upgraded; the person in charge of maintenance has been replaced; and a fantastic working relationship with an exceptional maintenance facility has been developed for the future.

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Original NASA ASRS Text

Title: An owner/operator of a Piper PA-28A aircraft used for flight training; reports unapproved maintenance methods; techniques and practices were used to accomplish upgrades on the PA-28. These upgrades were underlying factors in the ongoing maintenance issues the aircraft had experienced; including a recent inflight diversion.

Narrative: On a December night 2010; I received a mobile alert that the rental aircraft filed for ZZZ earlier had diverted to ZZZ1 due to experiencing electrical problems on an instrument flight. Since I was going to be out of town for six weeks; I contacted the pilot to inquire. Knowing this pilot's history of safety and attention to paperwork detail that is necessary in this industry; I asked if he would take charge of getting the plane repaired.34 days and two Maintenance facilities later; the electrical system was tracked down; repaired; signed-off and [the aircraft] is back in the hangar. However; after being briefed on the process; I found it fascinating; but also realized that even though I had an independent Chief Instructor in charge of insuring the legal endorsements and documentations were kept up; ultimately I need to be more involved in assuring these things are done. This was a wake-up call for me. The rest of this report is a description of the 'history-of-interest' during the troubleshooting phase of the electrical repair and the information that was uncovered. This is the written version from [discussions with] the pilot-in-charge: After flying aircraft to an away-from-base Maintenance facility and extensively studying the logbooks for the aircraft; which was rented from a local flight school; it was discovered that there were a number of omitted logbook entries and other missing or incomplete paperwork for the aircraft. The aircraft was not airworthy.An aileron was re-skinned and re-painted; with an FAA form-337 only partially being completed and without a copy being forwarded to the local FSDO. Additionally; there was no logbook record of the repaired aileron being removed or for it being reinstalled on the aircraft; nor for the aileron's balance being checked after painting; though the repairs were clearly accomplished.In the course of providing background information to the Repair facility; we investigated a number of components in the aircraft's charging system which had been burning-out voltage regulators; circuit breakers; and alternators on a regular basis for over a year. We discovered that the alternator installed in the aircraft was of twice the capacity of that approved for the aircraft. The over-sized alternator was; according to the logbook; first installed when the aircraft's engine was replaced with an overhauled engine at Repair Station X in 2009 -- when the alternator problems began (determined only with the benefit of hindsight). I do not believe the erroneous installation was intentional; though it has been costly; and apparently dangerous; for everyone involved.Subsequent replacements; accomplished by numerous [Repair] facilities; merely replaced the part number of the removed component without verifying its approval for the aircraft's serial number. Doing further research we came to the conclusion that although the particular oversized alternator was not approved for that specific year Airworthiness Directive (AD) serial number of aircraft and because of extensive avionics upgrades; the addition of a heated pitot tube; AD for the addition of anti-collision strobes; all done in 2005; an alternator of additional capacity would actually be required to maintain sufficient electrical power to the aircraft's electrical busses during a maximum load condition -- especially likely in IMC.It was also discovered that the alternator field breaker was wrong by any criteria used. The alternator amp-breaker was undersized for the alternator output; the alternator wiring was grossly undersized for the output capacity of the installed unit; and the ammeter (now mysteriously shunted) was not able to meter the rated capacity of the installed alternator. Though; thankfully the only damages were monetary; clearly such an installation was a fire hazard and not airworthy.Unapproved methods; techniques; and practices were evidently used to accomplish some of the upgrades performed in 2005; and this is an underlying factor in the ongoing maintenance issues this aircraft has experienced. All discrepancies on the aircraft have been satisfactorily corrected; the charging system has been completely upgraded; the person in charge of maintenance has been replaced; and a fantastic working relationship with an exceptional Maintenance facility has been developed for the future.

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.