Now, with this new survey, you can learn which airlines skimp on space so you can exclude them from your travel plans (until you find they're the only airline whose fare you can afford).
The survey measures leg room as the distance between the back of one seat to the back of the seat in front of it.
This method may be flawed (thickness of the seat back may differ) but it still provides a useful guide to those for whom leg room is an issue.
And, according to the survey, the airlines to avoid are Iberia with 28in (71cm) and EasyJet with 29in (73.6cm). Best performers were Cathay Pacific and Singapore Airlines, both on 32 inches (81cm).
If it's the width of the seat that is your problem, then the survey suggests avoiding Ryanair with its 16in (40.6cm) seats. Emirates offer top width with 20.5in (52cm).
These figures become particularly significant on long-haul flights. The longest single hop I've ever experienced is 13 hours by which time I'm in la-la land as I'm one of those who can't sleep on an aeroplane.
Except once, that is. Coming out of London, I decided to do what I shall tastefully refer to as "drink quite a lot" before the flight so I might "flake out".
Well, it worked and, lucky me, there were two empty seats beside me so I was able to fold away the armrests and have a snooze.
It was one of those milk run flights so first stop was Amsterdam. I had to wake up for landing which was when I became aware of the main shortcoming of my sleep method - screaming dry horrors.
But I had no idea until now that there are single flights of about 18 hours' duration! Where do they store enough fuel? How would they cope with passengers like me who would be in an advanced state of cuckoo-doolally-la-la cretinism.
Singapore Airlines was the holder of the dubious honour of longest single flight (Singapore to Newark) but they've canned that flight and the title is now held jointly by Qantas for their Sydney-Dallas hop and Delta Airlines for Johannesburg to Atlanta, both of which weigh in at a mere 17 hours.
Meals can provide some relief on long flights even if your timing gets all out of whack ("Have I just had two Sundays and three breakfasts?") but airline food can provide more bad news.
One day when you have little else to do, take a look at internet site, AirlineMeals, which, for 10 years, has featured travellers' photos of unspeakable airline food. You'll learn there's a lot to be said for the glass of water and cookie you get on our domestic flights.
Let's finish this high-altitude discussion with a worst case scenario. According to review website, Skytrax, the world's worst airline is Air Kyoto, a state-owned North Korean airline.
So, the worst case scenario? An 18-hour flight on Kyoto with 28in seat spacing, a yellow rubber omelette meal and, for good measure, a few screaming infants. Happy flying.