Qantas will flick the switch on its free inflight Internet service on Friday April 7 as challenger Virgin Australia readies a similar launch of its own sky-high WiFi technology later this month.

The Qantas WiFi trials will take place on a Boeing 737-800 jet (aircraft registration VH-XZB, if you must know) which will mostly dart along popular east coast routes between Sydney, Melbourne and Brisbane, with perhaps the odd east-west crossing (a 4+ hour journey where the ability to work online or just watch up with the latest Netflix show could come in very handy).

Passengers stepping aboard the Boeing 737 will be able to connect their laptop, tablet or smartphone to a WiFi hotspot and jump online for what Qantas promises will be a broadband experience good enough for streaming movies and live TV.

But before you ask: Qantas is unlikely to promote this first batch of 'sky-high WiFi' flights in advance due to the operational need to swap aircraft between routes (and with a fleet of some 75 Boeing 737s that leaves scope for a lot of swapping).

Recent real-world tests of the Qantas WiFi system have delivered typical download speeds between 7Mbps and 12Mbps to each connected device, providing ample overhead for streaming HD video content.

The airline previously hoped to begin public access to the Boeing 737's inflight Internet in February, and subsequently pushed back on a planned media launch in late March, due to "stability issues" with the satellite-based service.

"It’s quite a technical thing to do when you are trying to maintain a constant, high-bandwidth connection with a satellite as you’re travelling at 900 kilometres per hour" the airline said.

The airline is deliberately positioning this three-month trail as a 'beta test' for travellers to assess traffic loads and other real-world factors before locking down the Qantas WiFi spec for installation across the rest of its domestic fleet.

How Qantas WiFi will work

Qantas WiFi jets will connect to the NBN Co's pair of Sky Muster satellites which take all of Australia under their wing.

The Sky Muster birds pump out fast Ka-band signals which Qantas technology partner ViaSat says will deliver a 12Mbps pipeline to each connected device on the plane.

That's about the same clip as the fastest ADSL2+ home or office Internet services, and more than twice what's needed to watch Netflix in high definition.

“The technology we’re using makes us confident that we’ll be able to provide a fast internet connection to passengers" a Qantas spokesman told Australian Business Traveller.

"It will be enough to comfortably stream video and given we’re offering it for free, we expect take-up to be strong”.

A domestic Airbus A330 jet will be wired up – or rather, unwired up – around the middle of the year and expand the trial the Australia's transcontinental trek as part of a nine-month "proof of concept" test which will run through to September.

Qantas will then begin to roll out the same satellite technology to the rest of its domestic Airbus A330 and Boeing 737 fleet, although no decision has been made on similar upgrades for the regional Boeing 717, Fokker 100 and Bombardier Dash 8 jets of QantasLink.

Up next: international flights?

Expanding the inflight Internet service to international flights could follow, using ViaSat's global network to keep connected across the Tasman and en route to Asia, the Americas and Europe.

It's generally accepted that there is a greater appetite for inflight Internet on domestic flights – especially on Australia's transcontinental routes – than international flights, especially since around half of Qantas' international serves involve an overnight leg to Australia, which sees minimal demand because most passengers would rather sleep than surf the Web.

In late 2012 Qantas scrapped plans for Internet access on its flagship Airbus A380 fleet, citing a lacklustre response from travellers across a nine-month trial on selected superjumbo routes where the uptake was less than than 5%.