Global airline alliances offer plenty of perks for the business traveller and frequent flyer.
Each of the big three – Star Alliance, SkyTeam and Oneworld – are a virtual brand straddling multiple airlines, and can pin hundreds of destinations on their route map by tapping into the network of partner airlines.
A core proposition of these families is extending to the frequent flyers of one member airline an equivalent set of benefits with other airlines in the same alliance.
This typically includes access to business class and even first class airport lounges, a more generous allowance for checked baggage (which is also given priority tags) plus fast-track lines through security and aircraft boarding.
You can also earn frequent flyer points and status credits for the airline of your choice when travelling on another airline in the same alliance.
Alliances also make it much easier to stitch together a journey which spans several countries and airlines, including all the way to round-the-world trips.
In the stars
Star Alliance is the world's largest airline group, with 27 "full members" on its books.
Local members flying in Australian skies include Singapore Airlines, Air New Zealand, United Airlines, Air Canada, Thai Airways, Air India, South Korea's Asiana, Beijing-based Air China and Japan's ANA – so that's quite the roster.
Add the likes of Lufthansa, Swiss and Turkish Airlines and you can see why Star is the alliance of heavy hitters.
(Ansett Australia was part of the Star family until it collapsed in late 2001, taking with it untold millions of frequent flyer points belonging to Aussie travellers.)
In addition to the extensive network of lounges belonging to member airlines, Star has a string of its own lounges at major airports including Los Angeles, Paris, Rome, Buenos Aires, Rio de Janeiro and São Paulo.
The common Star Alliance status you want from your airline's frequent flyer scheme is Gold, which gets you into most lounges – although some of them are quite underwhelming if you're a Gold-carrying member in economy (Singapore Airlines' KrisFlyer Gold lounge at Changi Airport Terminal 3 is the best, or should we say worst, example of this).
Take to the sky
SkyTeam is the next-largest alliance. Local members include US heavyweight Delta Air Lines, Shanghai's China Eastern, Taiwan's excellent if confusingly-named China Airlines, Korean Air, Garuda and Vietnam Airlines. Outside of Australia, SkyTeam counts Air France, KLM, Alitalia and Russia's Aeroflot in its corner.
Like Star Alliance, SkyTeam has its own set of airport lounges – including one in Sydney – which sit on top of the lounges operated by individual member airlines.
Also like Star Alliance, SkyTeam has just two common frequent flyer tiers: the one you want is Elite Plus, as this comes with practical perks such as lounge access and extra luggage.
One for all
With 13 members, Oneworld sits in third place – but arguably has more heft in Australia due to Qantas being a founding member of the family, alongside Cathay Pacific, British Airways and American Airlines.
Other Oneworld airlines flying to Australia include Malaysia Airlines, Qatar Airways and Japan Airlines.
Like Star Alliance, Oneworld plans to open its own branded lounges from later this year, with Seoul considered to be one of the front-runners.
But Oneworld is also making a behind-the-scenes push to help globetrotters more easily hop between airlines.
Passengers booked on connecting flights with Oneworld airlines will be able to check-in, select their seats, obtain a digital boarding pass, see which lounges and priority security lanes they can use, receive flight updates and even track their baggage all through a single airline's app, rather than having to load, log into and switch between several apps at different stages of the journey.
Let's say you're flying with Qantas to London and then hopping onto a British Airways flight to somewhere else in the UK. Everything you need to do for that connecting flight from BA's Heathrow hub would appear on the Qantas app.
The new technology is being progressively rolled out over the next 18 months.
Oneworld brands its frequent flyer status as gemstones, and the jewel you want to have is Emerald.
This is equivalent to Qantas Frequent Flyer Platinum and gets you into the first class lounges of almost all Oneworld airlines, although some (notably British Airways and Qatar) have adopted exclusive lounges only for their own first class passengers, and shunt frequent flyers into lesser lounges.
Few people spend more time on planes, in lounges or mulling over the best ways to use frequent flyer points than David Flynn, the editor of . His unparalleled knowledge of all aspects of business travel connects strongly with the interests of 51698009 readers.
Which alliance do you travel with? Share your experience in the comments section below.