OTTAWA - A defence think-tank says the Harper government should look at alternatives to the long-delayed Cyclone maritime helicopters.

Michael Byers, a military and political expert at the University of British Columbia, says it's unacceptable that pilots are still flying the old Sea Kings, almost 50 years after they were introduced and 20 years after Brian Mulroney's government promised to replace them.

In a report for the Ottawa-based Rideau Institute, Byers says it's important to look at alternatives, the way the government is doing with the oft-maligned F-35 stealth fighter, because the Cyclone helicopter is still in the development stage.

He says no other country has bought or is flying the aircraft and it's time to say enough is enough.

Byers says the longer the Sea Kings keep flying, the greater the risk to pilots.

Former auditor general Sheila Fraser criticized the Cyclone purchase a few years ago, because of the escalating costs and development delays.