Travellers through Nelson airport are being warned to expect emergency service activity today - due to a fake aircraft crash

Up to 100 people from the airport's Rescue Fire Station, Fire and Emergency New Zealand and Hato Hone St John will be taking part in the full scale exercise starting at 10.30am.

Nelson Airport Senior Rescue Fire Officer Matt van der Heyden says they're required to do the exercises every two years, to test emergency procedures.

He says the area needs to be clear, and is asking the public not to cause congestion by coming to watch. The airport will remain fully functional.