Budget airline Norwegian Air Dreamliner flight from London to Singapore for $258: The world's longest budget flight

With headline fares from just £150 ($258) each way, Norwegian's new flights from Singapore to London's Gatwick promise to make the trip from south-east Asia more affordable than ever. But is travelling 10,885km, for 12 hours and 45 minutes, on what claims to be the world's longest budget flight, with luxuries such as food and checked luggage costing extra, actually a pleasurable experience? Thanks largely to Norwegian's new fleet of hi-tech 787-9 Dreamliners, yes it is.

I flew on the airline's inaugural flight from London to the city state yesterday. The legroom in economy class (31 inches, or 79 cm, with a precise 17.11 inches seat width - 43.45 cm) will leave taller travellers feeling a little cramped, and paying for snacks and drinks is always a drawback, but the service still offers very good value for money.

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The Dreamliner's ergonomic seats, bright and airy interiors, big windows and climate control buttons do much to add to the comfort levels already experienced on Norwegian's long-haul flights, now including 11 destinations from Gatwick alone. Gatwick to Singapore will operate four times a week. The in-flight entertainment is also free of charge and hard to fault - expect new release films and popular TV boxsets.

The big caveat, however, is that the lowest economy fares are only ever going to be snapped up by those who can be flexible about when to travel and who can plan and book their trips a long time in advance. On my flight, the excited couple sat beside me had booked their economy seats - "the cheapest option going" - around nine months beforehand.

Lorna Green had flown on one of Norwegian's short-haul European flights before and had enjoyed the experience. "We weren't worried about going in economy because we knew it was a new, nice plane and so the legroom would be good anyway," she told me. It was this that saw the pair drinking prosecco at the departure gate during the airline's pre-departure celebrations, while a lion danced at their feet.

For Lorna and her partner, and I suspect most Norwegian passengers, £150 ($258) was not the final cost of their flight. Checking in a bag will cost you an extra $43 each way, and two meals (which you'll probably need during almost 13 hours in the sky) costs another £25 ($42). Book both of these in advance and you also get to choose your seat. So that's an extra £100 ($172) per person per return flight unless you want to travel to Asia with only hand luggage and a handsome supply of snacks to keep you going.

And those £150 fares really are elusive. Looking at departures in October, Norwegian's lowest rates simply cannot be found. The cheapest available one-way ticket, departing on October 30, costs £279 ($480) (or £329 [$566] once you have paid for a checked bag and a couple of meals). Add a return flight a week later and you're looking at a minimum spend of around £470 ($809) (or £570 [$981] if you want checked luggage and food).