More than 100 flights out of Sydney Airport have been delayed due to staffing issues within the air traffic control tower.Air traffic controllers Airservices Australia says Friday morning’s issue has been resolved.Australia’s peak body for airlines has slammed the delays, which led to at least 110 international and domestic flights out of Sydney Airport delayed, with some sitting on the tarmac for two hours.The Sydney Airport website also crashed shortly after 2pm: “There might be too much traffic or a configuration error”, the website error message said.In a statement, Airservices Australia said it had delayed the flights because of “operational restrictions”.The government-owned corporation “enacted Air Traffic Flow Management measure at Sydney Airport”, “due to operational restrictions to safely manage projected airborne and departure demands”.“Airservices acknowledges the (air traffic flow management) measures, which have now been removed, caused disruptions to airline scheduling, however capacity has now been restored and no further significant delays are anticipated,” the spokesperson said.“Airservices air traffic controllers are incredibly proud and dedicated to performing what is a demanding, safety-critical role.“We take their wellbeing and psychosocial safety seriously and ask that commentary on operational performance recognises the professionalism and commitment of the controllers working every day to keep the travelling public safe.”At least 56 Qantas international and domestic flights were delayed, and four were cancelled.Virgin cancelled two flights and delayed 20.Twenty-five Jetstar planes were delayed, and regional carrier Rex reportedly had to offload passengers and send them back inside.Peak body Airlines for Australia chief executive, Stephen Beckett, said the “catastrophic” delays will have the knock-on effect of people missing their international flights.“This is a persistent problem that Airservices says they have fixed,” Mr Neckett said.“Australia has an incredibly safe aviation system and our air traffic controllers do a fantastic job – we need Airservices to ensure they have enough people and robust rosters to do the job.”He offered a glib assessment of Airservice’s issues.“Another day, another Airservices delay. Tens of thousands of Australian travellers will have their commute impacted by this – they will miss international connections,” Mr Neckett said.“This is catastrophic for the national network – we need to know what is going on.”More to comeRead related topics:Sydney