Qantas Airways Ltd. expects to release preliminary results of its in-flight phone trial later this year.

While the technology is almost ready to allow passengers to use their mobile phone during flights, they shouldn't expect to do so anytime soon.

Qantas has extended until February 2008 a technology trial that allows passengers to send text messages and emails from their mobile phones during flights, with the plane acting as a mobile phone tower. Passengers roam onto the tower as they normally do when travelling overseas.

In April, Australia's communications regulator, the Australian Communications and Media Authority (ACMA), gave Qantas a 12 month window of opportunity to temporarily test the service on one of its planes, a Boeing 767 travelling domestically.

While Qantas had initially flagged plans for a three-month trial, company spokeswoman Holly Williams told The Australian Financial Review last week the test period had now been extended, and was slated to finish early next year.

"They figured they might as well use the entire period to evaluate customer responses," Ms Williams said of Qantas's technical team.

Qantas expects to release preliminary results of the trial later this year.

Qantas's efforts come as other carriers, such as Dubai's Emirates Airlines, flag similar trials this year although most remain concerned that mobile phones, which use a specialized form of radio waves, have the potential to interfere with in-flight signalling equipment.

Virgin Blue spokeswoman Amanda Bolger said the carrier did not offer any internet, SMS or mobile phone options on its planes, although the matter was under consideration.

ACMA and other government groups will consider permanent regulatory arrangements for in-flight mobile services once Qantas releases its results from the trial.

The Qantas trial involves the use of a so-called network control unit that acts like a tiny mobile phone tower connected by satellite to ground networks.

In-flight mobile voice services could also be even further away than mobile text and email services. Qantas's trial does not allow voice services, reportedly due to the need to prevent talkative passengers from disturbing others.

Passengers on Qantas flights can already communicate via available telephones located in their seats. However, they may soon have another option.

In July, the airline announced it was planning to buy a number of Airbus A380s, which would provide wi-fi internet capability throughout the plane. This is in addition to in-seat access to email, the internet and SMS.

The planes will also feature USB and ethernet ports as well as the ability to power laptops.