Canada's new multibillion-dollar stealth fighters are expected to arrive without the built-in capacity to communicate from the country's most northerly regions — a gap the air force is trying to close.

A series of briefings given to the country's top air force commander last year expressed concern that the F-35's radio and satellite communications gear may not be as capable as that of the current CF-18s, which recently went through an extensive modernization.

Military aircraft operating in the high Arctic rely almost exclusively on satellite communications, where a pilot's signal is beamed into space and bounced back to a ground station.

The F-35 Lightning will eventually have the ability to communicate with satellites, but the software will not be available in the initial production run, according to a senior Lockheed Martin official.

It is expected to be added to the aircraft when production reaches its fourth phase in 2019, but that is not guaranteed because research is still underway.

"That hasn't all been nailed down yet," the official said.  "As you can imagine there are a lot of science projects going on, exploring what is the best … capability, what satellites will be available."

Additionally, Canada's request to have the upgrade placed in the fourth phase will compete with software changes sought by other countries. Norway, for example, wants to use its own missiles on the F-35 rather than U.S.-made weapons.

Defence Minister Peter MacKay, speaking to Evan Solomon on CBC's Power & Politics, said Canada won't be getting its planes for five years and there should be a solution by then.

"It's only speculation and quite frankly fearmongering on the part of the opposition," he said. "There is still, obviously, a lot of work going on with respect to the development of certain aspects of the F-35 that we will receive."

Many of the modifications needed are straightforward, the minister said, adding "some of the other criticisms, as well, are based on hypothetical situations five years away."

Communications in Arctic a 'challenge'

Defending the Arctic is one of the Harper government's key justifications for buying the aircraft, which are estimated to cost between $16 and $30 billion, including long-term maintenance.

A defence department spokesman denied that the F-35's communications suite will be less effective than that of CF-18s, but acknowledged that so-called beyond-line-of-sight communications is a concern.

"Communications in the Arctic represents a specific challenge to all aircraft due to lack of satellite coverage in the North," Evan Koronewski said in an email response. "Canada is working closely with the other partner nations to ensure Canadian operational requirements for communications in the Arctic are met."

Air force planners recognized the problem last year and are "considering a back-up," said an April 2010 briefing.

A study is looking at whether an external communications pod can be installed on the F-35. The sophisticated pods, which are carried by the CF-18s, were purchased as part of the $2.6-billion fleet upgrade that began in 2000.

Installing such pods could be made more affordable if other countries participated, the briefing to the chief of air staff noted.

The communications problem is just one of several technical issues the air force is working on. National Defence has also asked the U.S. manufacturer whether it's possible to install a different air-to-air refuelling system on Canadian F-35s.

with a file from CBC News