29 CFR §1926.1429

1. (a)Maintenance, inspection and repair personnel are permitted to operate the equipment only where all of the following requirements are met:
   1. (1)The operation is limited to those functions necessary to perform maintenance, inspect the equipment, or verify its performance.
   2. (2)The personnel either:
      1. (i)Operate the equipment under the direct supervision of an operator who meets the requirements of § 1926.1427 (Operator qualification and certification); or
      2. (ii)Are familiar with the operation, limitations, characteristics and hazards associated with the type of equipment.
2. (b)Maintenance and repair personnel must meet the definition of a qualified person with respect to the equipment and maintenance/repair tasks performed.