Invercargill woman Wilma Keable boarded her Air New Zealand flight to London in the middle of last year a healthy 74-year-old.
She touched down at Heathrow with two blood clots on her lungs.
Forty-six days later, Mrs Keable died in an Edinburgh hospital from deep vein thrombosis (DVT).
DVT, known as economy-class syndrome, affects people who sit for long periods, increasing their risk of developing blood clots in large veins, where blood flow is sluggish.
Despite several letters to Air New Zealand, Mrs Keable's family have not received an apology.
Her children have now joined almost 30 other New Zealand families affected by DVT, and will take a case against the airlines through Wellington lawyer Roger Chapman.
"We're putting off any major action until we get a clear indication from overseas," Mrs Keable's son, Michael, said yesterday.
"Airlines have known for 30 years that there is a problem, but they have failed to do anything about it."
It was likely to be at least 10 years before any sort of settlement was made.
"It's a repeat of the cases against the tobacco companies.
"The Government made the labelling laws for cigarette packets official before any settlements were made with the companies, so what we're saying is why can't the governments make some sort of decision now."
Hospitals needed a central agency for reporting cases of DVT to, so doctors could better understand the illness and people it affected, he said.
Mrs Keable's flight had been plagued with problems. The air-conditioning system on the plane broke down, as did the refrigeration unit, meaning warm drinks all the way to London.
"It certainly wasn't ideal. The stopover in Los Angeles was basically taken up with security checks to get them off and back on the plane, so there wasn't a lot of time to walk around, which Mum always did when she was travelling," Mr Keable said.
Last night Air New Zealand said it knew nothing about the case.
"We don't know anything about it. And we certainly wouldn't be discussing it in the media," spokeswoman Rosie Paul said.
The family could write to Air New Zealand to voice their concerns, she said.
When it was pointed out this had already been done twice, she replied: "Well, I don't know anything about the case, and we won't be commenting."
- NZPA
Herald Features:
Economy class syndrome
Health
Air NZ faces blood-clot action
AdvertisementAdvertise with NZME.