An air passenger's right to compensation in the event of a delay is subject to the distance of the flight and the duration of the delay.
According to decisions handed down by the European Court of Justice (cases C-402/2007 and C-432/2007), passengers who arrive in their destination over three hours later than originally scheduled are entitled to the same standard compensation as passengers whose flights are cancelled. With the Court's decisions still being fairly recent, there isn't much experience of their practical implications.
The amount of compensation, if applicable, is determined by the distance of the flight and the length of the delay caused by re-routing. The airline can pay passengers the reimbursed cost of the ticket and the compensation amount in cash, by bank transfer, by cheque or, with the signed agreement of the passenger, in travel vouchers or other services.
You may claim compensation for damages arising from a delay. Compensation for damages only applies to costs for which you can provide evidence, for instance a rail ticket that is left unused due to a delayed flight, but not for disappointment or emotional distress. You should retain receipts as evidence for claiming damages. The maximum compensation for delays is approximately 4,150 special drawing rights, which corresponds to EUR 4,635. Compensation for damages can be deducted from standard compensation paid by the airline, if applicable.
An airline is not liable for damages if it can provide proof that it took all measures that can be reasonably expected to avoid the damages in question. Standard compensation generally does not apply in cases where delays are caused by weather conditions, security risks or air traffic controllers being on strike. However, the airline must provide proof of the cause of the delay and justify the actions it took.
Related legislation: EC Regulation No 261/2004 establishing common rules on compensation and assistance to passengers in the event of denied boarding and of cancellation or long delay of flights Convention for the Unification of Certain Rules for International Carriage (Montreal Convention)