What reasons does LVNL have to issue the captain with a different instruction?

Safety takes priority in aviation. In order to avoid a dangerous situation, LVNL may instruct captains to deviate from their route. Sudden changes in weather conditions may also be a reason for deviations. Another reason why LVNL may issue additional instructions is to avoid take-off delays during peak periods. LVNL aims to limit the number of outbound flights by jet aircraft above connected built-up areas at an altitude of less than 3,000 feet (about 900 metres) as a result of such instructions to no more than 3% of the total number of take-offs by jet aircraft.