The board found that use of non-standard phraseology between the Maputo controller and the crew led to confusion about the status of the ILS signal and whether the runway lights were on. The flight crew's repeated requests to "check runway lights" were interpreted by the controller, based on the use of the word 'check' in civil aviation, as confirmation by the crew that they had the runway lights in sight. The aircraft had not refueled at Mbala before departing and did not have enough fuel remaining to reach the intended alternative airport in Beira, Mozambique by the time it reached Maputo. This may have greatly increased the pressure on the crew to continue with the landing approach to Maputo despite the difficulties encountered.