M.A.609 Maintenance data

The approved maintenance organisation shall hold and use applicable current maintenance data specified in point M.A.401 of this Annex or in point ML.A.401 of Annex Vb (Part-ML), as applicable, in the performance of maintenance, including modifications and repairs. However, in the case of customer-provided maintenance data, the organisation shall only hold and use such data when the maintenance work is in progress.