Which airline is the cheapest for domestic flights?

[Robbie W]

I am based in Sydney and soon I will occasionally need to travel to Melbourne or the Gold Coast for work purposes.

Often I will only need to be there for inside of a day - leave Sydney in the morning and return that night.

Which airline is the cheapest? I will only have carry-on luggage.

On rare occasions I may need to stay overnight for a day or two at my destination, in which I might have a small bag for checked-luggage, containing a change of clothes.

[David C]

Robbie ... I would suggest looking at www.iwantthatflight.com.au ... This will provide you with a good overview of fares , routes etc. for a given period ..

Dave C

[Ash W]

I am based in Sydney and soon I will occasionally need to travel to Melbourne or the Gold Coast for work purposes.

Often I will only need to be there for inside of a day - leave Sydney in the morning and return that night.

Which airline is the cheapest? I will only have carry-on luggage.

On rare occasions I may need to stay overnight for a day or two at my destination, in which I might have a small bag for checked-luggage, containing a change of clothes.

No such thing as the cheapest airline. On any given day any of the airlines can the cheapest.

[Skip Fulton]

Which airline is the cheapest?

This is the eternal question Robbie.

Airlines are very heavily focused on revenue/yield management. This is the art of adjusting prices to cater for changing buyer behaviour and the buying environment.

Airlines have many different fare structures. For any given flight there are usually between 5 and 15 different fares. At the bottom end is the cheapest fare with the tightest conditions. Whilst at the top end is the more expensive fare with the most relaxed conditions.

In a hypothetical scenario of a 200 seat aircraft flying Sydney to the Gold Coast. The cheapest fare might be $59 and there are 30 seats available. Once they are sold, the next available fare might be $69 and there are 15 seats at that price. The next is $89 and there are another 15 seats and so on. All the way up to the fully flexible fare at $299, at which price they'll sell you every seat on the aircraft. The number of seats in each fare structure are actively managed by the airlines (and more importantly by their yield management systems).

So it naturally follows that the earlier you book, the cheaper price you are going to get. So the cheapest price might be on Jetstar by $5 over Virgin Blue. Jetstar's first 30 seats will sell first and then their price will rise to the next fare bracket. Now Virgin Blue might be cheaper by $5 and their seats will sell. There are definitely a lot of other factors that go into buyer behaviour and the buying environment, eg: flight departure/arrival time, inflight entertainment, inflight meals, frequent flyer membership, are you booking yourself or on a corporate account etc

This is why you'll also find different fares for the same flight on different days of the week. A Friday afternoon SYD-OOL is likely to be a lot busier than the Tuesday midday flight. Thus the Friday afternoon flight may only have 20 seats at the cheap $59 fare whilst on Tuesday there's 40 seats at the same price.

So when Ash says 'No such thing as the cheapest airline. On any given day any of the airlines can the cheapest', he's absolutely right. Day of the week, time of day, school holidays or not, how long you are booking in advance etc all impact what fare you are going to pay.

Just to give you example. I looked at SYD-OOL one way on 15 July next year on webjet.com.au (did this far in advance to show cheapest fares)
Tiger - $59, check-in a bag and its $84
Jetstar - at 6am its $69 plus $10 for a bag, at 5pm its $99 plus $10 for a bag
Virgin Blue - 7am its $90 plus $10 for a bag, at 4.10pm its $119 + $10.

So who has the cheapest base fare, its Tiger but you have no flexibility as they only have one flight a day at 4pm.

Yield management gets a whole lot more fun when you introduce all the other factors that go on, Upgrade/downgrade aircraft size, school holidays, large sporting events, conventions, flights designated with international connections and my all-time favourite - what is the opposition doing. Just watch when an airline cancels a flight for whatever reason - all the cheaper fares for the competition for the rest of that day on the same route suddenly disappear.

Good luck with your travels with work. And if you are staying overnight, find a way just to have carry-on and save yourself $10 a flight (or fly with Qantas who don't charge for it).

[Owen H]

All I'll say is look at all of the airlines, their origin/destination, as well as included extras before deciding.

The number of people that have booked a flight to Melbourne - Avalon because it is $20 cheaper than going to Tulla, and then realising the cab fare is $50 more and takes another 30 minutes is quite amazing.

I'd also say don't forget to look at the so called "expensive" carrier like Qantas. Many people assume they are expensive and don't look - while it is not that unusual for Qantas to be the cheapest fare available on a given flight.