Most Air New Zealand air bridges are in need of a major overhaul according to a confidential report commissioned by the airline, which was leaked to One News.
It found a Christchurch air bridge has structural defects while others in Auckland are past their useful life and need to be replaced.
It is something most people take for granted, when they board or disembark a plane through the corridors that connect planes with their terminals.
"The real danger would be if the thing stopped functioning, either part way through an aircraft loading, or as an aircraft is docking," national secretary of the Engineer's Union Andrew Little says.
The air bridges were installed about 18 years ago. But the supplier's recommended life span is only 12 years and the report says they are "all beyond their intended service life."
However the American designers say air bridges can last up to 30 years if they have very good maintenance.
"You know you can certainly prolong the life of the equipment by doing good periodic maintenance," Steve Lefevre of FMC Technologies in Utah says.
Air New Zealand admits that maintenance could have been better.
"There were opportunities for us to have actually undertaken some repairs throughout the life of the air bridges, which should have been done sooner, but we're acting on those now," Air New Zealand networks manager Norm Thompson says.
The airline is now calling for tenders to replace three Auckland air bridges, which cost about $1 million each.
The report says additional upgrades will "reduce the amount of bridge failures," but Air New Zealand stresses there is no evidence of any incident or threat to the public.
"There is absolutely no public safety issues at all. Air New Zealand is not negotiable when it comes to safety," Thompson says.
The person who leaked the report to One News did so because they thought Air New Zealand had failed to act on the information. But the airline says that is not true.
"I can assure everyone that the report is being taken very seriously at Air New Zealand and is being acted upon," Thompson says.
The report says bridge 18 in Christchurch is in the "worst overall condition" because of structural defects and corrosion.
Air New Zealand says it has suffered some "impact damage" and because it's the country's longest air bridge care has to be taken to stop it warping in high winds.
The engineers union says the Department of Labour needs to be involved.
"They need to be involved in assessing the hazards and the safety or potential risks associated with this. They have a clear responsibility," Little says.
Souce: One News
Video: http://tvnz.co.nz/view/video_popup_windows_skin/715263