"A Northwest Airlines aircraft, flight number Northwest 42, returned to Schiphol Wednesday 23 August at 11:30 escorted by two F-16's. The aircraft had departed to Mumbai with a delay and requested just before the german border to Amsterdam Radar to have a 'security escort' and to return to Schiphol airport. The reason for the return is unknown at the moment. From 11:10 onwards Northwest 42 has dumped kerosine over the IJsselmeer and at 11:19 uur it has been intercepted by two F-16's coming from Leeuwarden airbase and escorted to runway 27. De F-16's, AJ-60 with tail number J-623 en AJ-23 with tail numberJ-204 were at that time practicing in TMA-D (practicing airspace near Volkel) under the supervision of Dutch fighter control Bandbox and could quickly get to the aircraft requesting assistance. The NorthWest aircraft had earlier this morning landed at Schiphol at 6:15 coming from Minneapolis in the United States. Upon return to Schiphol the aircraft went to gate E77. During the return to Schiphol emergency frequency 120.875 Mhz was used while the F-16's were on Bandbox at 376.775 Mhz, with Schiphol at 131.150 Mhz and at 140.875 Mhz between them. The last frequency was used by the F-16 pilots in secure mode. This encryption (KY-58) Was used shortly during the climb from Schiphol after the Northwest aircraft had landed safely, making this part of the communication inaudible"