Key Points:

A large woman from South Africa sat on the aisle seat on our flight from Auckland to Singapore. Not only did she encroach on my wife's seating space but the arm rest between them had no chance of being lowered.

"The lady was unable to lower her table to eat from, so she had to support her tray with one hand after getting either my wife or airline staff to cut up her food for her, and needed a member of staff to assist her out of her seat every time she wanted to stretch or use the toilet.

"Worst of all, her location meant a journey completely devoid of any opportunity to exercise or use the facilities ourselves as the aggravation wasn't worth it. Ironic that we relatively active people were exposing ourselves to an increased DVT risk as a result of this person."

This anecdote from James Blackburn is one of numerous horror stories sent in response to the article (Travel, April 10) about the problems caused by over-sized people trying to fit into under-sized airline seats.

Greg Thomas, for instance, described a direct flight to South Africa when "a really fat lady was seated next to me and just overflowed all over me. I couldn't move until we had taken off at which point I excused myself and stood for the entire flight all the way till Johannesburg. I am not even sure that if this person had two seats allocated she would have been able to fit properly."

Deborah described "sitting for 12 hours in bulkhead row squished between two fat people, one of whom occupied more than a third of my seat, who had to lift their fat every time I wanted to get the tray out, watch the entertainment, etc."

Danny Clevely plaintively recalled "having a rather large woman fall asleep over me on a flight to LA. Help!"

It's a subject that obviously strikes a nerve with many airline travellers, because not only did it spark a torrent of emails - 93 at last count - but also most were very angry about their experiences sitting alongside extra-large passengers.

A few, like Sandra Gibbs, blamed airlines for making the seats too small. "If the airlines were realistic about the amount of seating in a plane and didn't try to cram everyone in like sardines then there would be enough space for all. Even normal-sized passengers encroach on neighbouring seats as they sleep. In the name of profit comfort is sacrificed."

But the vast majority recognised that making seats wide enough to fit the over-sized would mean higher air fares for all.

As Graeme Bain put it, "By making seats wider healthy people would have to pay for the poor personal choices of overweight people by paying more for their seats."

Garry Pellett felt a more logical approach would be, "Obese people should pay the extra cost of travel, not the general public who comply with standards. It's about personal responsibility."

But while there was a high level of agreement that ordinary passengers should not have to put up with the discomfort or cost of dealing with the over-sized there was a wide range of views on how to achieve that.

Peter Kammler had a simple answer. "When ticketing, have airlines ask the approximate weight of passengers, then allocate seats so that the fatties are sitting next to each other. Perhaps that will teach them."

Wendy James wanted airlines to "provide a girth measurement so people know how many seats they need to book for themselves. I certainly don't want someone's fat spilling into my seat. Most fat people are fat because they overeat. If they can afford to overeat, they can afford to pay their share of flying."

Similarly, Elaine Pollock suggested putting normal airline seats into airline offices and travel agents "so passengers who know they are overweight can check as to whether or not they will require a special seat. Failure to check should result in being declined a seat on the plane if allowing them to fly would mean denying another passenger the comfort of their allocated seat."

Bain commented bluntly that, "Overweight people should face up to themselves and either pay for a second seat, upgrade to the front or not fly until they have dealt with their weight problem. As a once-obese person, I had to deal with my weight problem several years ago, and it was one of the best things I could have done for myself."

Deb McAlister said she and her husband - "both large people, though we wouldn't consider ourselves obese" - already take that approach. "We buy three coach seats on Air New Zealand and Qantas. By booking ahead and getting guaranteed seats we don't infringe on anyone except each other. "

Jan Zander, however, thought airlines should "provide an area at the rear of the plane that could be screened for privacy that has a small number of wider seats that they could book in advance at a slightly increased price."

And Ian Graham thought that at the rear of the aircraft where the body becomes narrower and the 3-4-3 configuration changes to 2-4-2 "it should be possible to have at least one of the two window-side seats slightly wider with no change in seating capacity. There could be a surcharge for passengers choosing a wide seat at check-in."

Geoff Long was one of many who proposed that airfares should be based on combined body and baggage weight, since "it goes without saying that a person weighing more will require more fuel to transport". Therefore he suggested airlines should weigh every passenger with their baggage and charge accordingly. "With the extra revenue generated, airlines should make economy seating of different sizes to cater for varying passengers."

Geoff Durham would make an exception for anyone able to provide evidence of a medical condition being responsible for their size. "In the absence of such explanations it would seem fair that they pay for additional weight/volume. Simply weigh everyone and they can decide whether to pay excess or take less luggage."

Andrew Stevenson was one of several readers who drew an analogy between overweight passengers and excess luggage. "The reason allegedly behind excess luggage charges is that weight causes the airlines to use more fuel. So all passengers should be given a maximum weight allowance of say 150kg which includes check-in, carry-on and body weight. Why should a 50kg waif have to pay for excess luggage but a clinically obese 140kg person not pay any extra?"

Colin McMurray believes there is a principle at stake. "When you buy a seat on a flight you are not just buying the seat itself but more importantly the space in it, and I believe you are absolutely entitled to have that space all to yourself for the majority of the flight. If the passenger next to you is encroaching on your space you should be refunded a proportion of your fare."

McMurray, too, thinks the solution is charging according to weight. "The airlines aren't shy about charging by weight anywhere else on the plane. If I check in with 35kg more baggage than my fellow passenger I get nailed with additional charges. But if he weighs 35kg more than me and takes up extra space in the cabin he currently gets off scot-free. It is costing the airline more to fly him to the destination than it is me and that should be reflected in his fare."

Dennis Johns has already put that approach into practice following an Air NZ domestic flight a couple of years ago when found himself "seated next to a very large person who could not get the arm rest down and took about a third of my seat. I put up with it but subsequently complained to Air NZ and got the usual platitudes.

"After much correspondence ... I invited them to argue it in front of the Small Claims Tribunal. The next correspondence from them was a credit note for the amount of the fare.

"The airlines hide behind spurious arguments on this matter. A customer pays for a seat and the airline has to provide a seat. If they let on a person who overflows into the next seat and it has to be occupied they are not keeping to their side of the contract. They have to deal with the problem and the easiest way is to make anyone who can't fit buy another seat."