New Zealand Defence Force Iroquois helicopters will be pulled from service in East Timor in October, and will not be replaced.
The two Iroquois will be sent on their final deployment from Palmerston North on Monday, spending three months in the capital Dili.
The Iroquois have been used their current deployment in East Timor since April last year.
October had already been determined as the date for the Iroquois to be pulled out of East Timor, because a new model is being introduced in 2010.
The Defence Force says the Iroquois would still have been useful in East Timor, but the 30 personnel who crew them need time to be trained with the new helicopters.
Commodore Gavin Howse says 100 other Defence Force staff will remain in East Timor when the Iroquois leave.