End pay incentives for area managers for   

Agree 100% any form of financial compensation or influence can have a negative impact on the overall safety aspect of an operation.  Any matrix you apply can have some sort of negative connotation.  They all boil down to flights/mission capable or completion rates.  Those rates in themselves can be twisted to appease those above.  You could be plagued with the "hangar bird" or lack of material support (parts), weather, personnel issues (to include mechanic availability),...  Even outstanding tenure does not reflect the "perfect" scenario.  Crew could be there just because the location fits their personal agenda where the job is just a job.  Even customer reviews can be misleading.  The bonus can be a double edged sword.