The flight, with the co-pilot at the controls, was cleared to the Outer Marker (CU NDB) for an ILS approach to runway 35. After passing the NDB the pilots switched to ILS and thus couldn’t verify their position in the procedure turn. The aircraft was outside the 35deg sector of the ILS centreline and the crew followed the wrong side beam. The crew descended to Outer Marker altitude and the 737 struck Dmentepe Hill, 10,5nm from the airport. The aircraft disintegrated and burned. PROBABLE CAUSE: “The accident occurred due to the wrong use of navigation aids. The cause is attributed mainly to the lack of adherence to company procedures especially in respect of crew coordination during approach and basic instrument flying procedures.”