Why have unlimited flight passes disappeared?

Until 10 minutes before the plane left, I had no idea I wanted to go to Edmonton. The Alberta provincial capital is not overflowing with appeal, but from the point of view of a budget traveller the relative weakness of the Canadian dollar meant a night’s stay would be cheaper than on the US side of the border. And besides, the Airbus A320 had some empty seats.

The location was Minneapolis-St Paul airport, somewhere I spent a fair amount of time in the late 1980s and early 1990s. The reason: it was a primary hub for Northwest Airlines. And Northwest offered a one-month unlimited travel air pass for $499 (then £335). For under £11 per day you could fly far and wide across the US and Canada, so long as there was a seat available.

In the low-density days three decades ago, there usually was space on North American flights: high fares, relative to today, made sure of that.

So Northwest, along with its then-competitor, Delta, earned some incremental revenue by selling overseas visitors air passes.

Travel was entirely standby, with the small print warning that you could be hauled off the plane (figuratively) before departure if a proper fare-paying passenger turned up. That never happened to me, and on the rare occasions when your chosen flight was full at the hubs (which also included Boston and Memphis for Northwest, and Atlanta, Dallas and LAX for Delta) you could always find a plan B – even if it did involve Edmonton.

The airpass traveller could cut the cost of accommodation still further by taking overnight flights – especially from the west coast to the east, which typically departed close to midnight and touched down around 7am.

Sometimes, it was tough to find a way out of some of the cities at the end of the “spokes”: after a fruitless day at Austin, I had to rent a car to drive to Dallas. But for covering lots of ground the airpass was way ahead of the Greyhound bus and Amtrak train unlimited travel deals.

Like all good things, it came to an end. In April 1994 both Delta and Northwest stopped selling the passes. A cheap and flexible transcontinental option for North America continued with Air Canada’s regional operation allowing you to hop (painfully slowly) from the Atlantic to the Pacific for a couple of hundred dollars.

The concept struggled into the 21st century, but airlines such as AirAsia have tried offering unlimited standbys and then dropped the concept. I understand that was partly because of the logistical complications involved, and partly because of the issue of “abstraction” – with passengers who would be prepared to pay proper prices on AirAsia taking advantage of the airpass to save cash.

British Airways offers a kind of airpass – through Optiontown, it sells multiple flights on specific routes at fixed fares. But I priced up six one-way flights between Heathrow and Edinburgh, to be used in the course of a year and bookable up to four hours before departure, and the price per hop is £175. No thanks.

But this week’s kerfuffle over Interrail – “we’re in/out/in again” – made me wonder if a standby airless could ever work.

I think it could, and the place to start: Flybe, soon to be rebranded as another Virgin carrier. Because most of the carrier’s routes have reasonable alternatives – particularly domestically within Britain – I would be happy to take my chances.

At the start of the year, I would cheerfully pay, say, £500 for 10 flights over the course of the year. Putting people like me on standby is a gentler and less risky alternative to overbooking.

I could register for my intended flight online, and get a sense of whether I was likely to fly. Were I consistently unlucky, I would expect some of my cash back for unused flights – and conversely if I used all the flights within six months, Flybe could decide whether to offer me more.

Extras, notably checked luggage, would cost more – offering the airline more incremental revenue.

Perhaps the new management would like to test the idea. I can even offer a name for it: Interfly. You know where to find me.