Warning on Grand Canyon

The century-old track, one of the country's most popular, provides a tranquil experience for visitors as it meanders into the heart of the World Heritage Area. The track recently underwent a government-funded restoration, worth $4.8 million, and was officially reopened in 2017.

Recognised as a key eco-tourism destination, attracting roughly 200,000 visitors a year, the Grand Canyon's peace is at risk of being ruined by helicopter noise if commercial development of the airfield goes ahead. It sits merely 700m away.

Society president, Tara Cameron, said: "It is quite astounding that the government can invest a considerable amount of taxpayer funds into restoring such a precious environmental asset for eco-tourism, then three years later risk ruining it all because of pressure from a developer.

"Any helicopter noise so close to the Grand Canyon will be absolutely devastating for visitors, who are flocking to the area for its tranquility. It will also significantly impact on wildlife, migratory birds and the local community."

The lease application by FlyBlue was initially rejected but is now being reconsidered by the state government.

"The site is totally surrounded by UNESCO-listed World Heritage National Park. The only way to protect the sanctity of the Grand Canyon is for the government to uphold its original decision, not be swayed by the developer and to have the site incorporated into the park," Ms Cameron said.

A spokesman for the department of planning, industry and environment said: "The department is waiting on FlyBlue to submit further information on its revised proposal and how it would meet the requirements of the Environmental Planning and Assessment Act 1979.

"If this can be demonstrated, the amended lease proposal for the Katoomba Airfield will be considered in detail and, if supported by the department, will be subject to further community engagement prior to a final decision being made."

Director of FlyBlue, Floyd Larsen, said she did not wish to comment.