Exhibit 10.4a


Under APS' 2001 Management  Variable Incentive Plan, the Chief Executive Officer
of APS,  with the  approval  of the Human  Resources  Committee  of the Board of
Directors,   annually  designates  employees  to  participate  in  the  program,
establishes  their  participation  level, and establishes  certain financial and
operational  goals for APS which must be  satisfied  in order for  variable  pay
awards to be made. The impact, if any, of each employee's  performance on his or
her variable  pay award is  determined  by his or her officer.  Subject to final
approval by the Human Resources  Committee of the Board of Directors,  the Chief
Executive  Officer of APS also  determines at year-end the degree to which those
goals  have been  satisfied  and the  amount of  variable  pay to be  awarded to
participating employees, if any.