There were nine go-arounds in a row at one point at Heathrow, and 40 in total between 07:00 and 14:00, when usually we might see one a day. Add in similar problems at other airports and you’re suddenly dealing with a very complex, dynamic and challenging environment.
Airspace infringements by General Aviation pilots entering controlled airspace remain the biggest risk to the air traffic operation and they are becoming a daily occurrence in the summer months. An infringement occurs when an aircraft enters a volume of airspace without gaining permission, and they can have a huge impact on the system causing aircraft to be diverted, put into holds or held on the ground.
Aircraft are hit by lightning far more frequently than you might think and, although this could cause serious damage and result in lengthy delays, most of the time it goes completely unnoticed.