Complex sentence: Since April 2013, South African contractors have taken over prime responsibility for maintenance work on the Gripen fleet, all previous support contracts with Saab had expired; this arrangement has led to fears that extended operations may not be possible due to lack of proper maintenance.
Split into simpler sentences: Since April 2013, South African contractors have taken over prime responsibility for maintenance work on the Gripen fleet, as all previous support contracts with Saab had expired. This arrangement has led to fears that extended operations may not be possible due to lack of proper maintenance.