Adherence to Filed Flight Plans in European Airspace
It is important that aircraft operators and ATS adhere to filed flight plans unless there are safety reasons.
There can be strong incentives for pilots to try to recover delays or save costs by choosing another route or lower/higher altitude. However, if too many flights do this, the entire network planning is at risk, thus resulting in further delays in the whole system including airports and potentially also in increased safety risks.
Click here for more information: Adherence to Filed Flight Plans.pdf