A Boeing 737 passenger jet has been performing take-off and landing trials at a Kent airport which is seeking permission to expand.
The Boeing 737 made three flights over Romney Marsh
The aircraft spent three hours at London Ashford Airport (LAA) in Lydd on Saturday flying circuits of the area to try to dispel objectors' fears.
The jet is the type that will be used if the airport is granted planning permission for the expansion.
Lydd Airport Action Group is calling for a public inquiry into the plans.
Airport managers said they had paid a five-figure sum to hire the Boeing 737-300 series but it would be money well spent if it helped to demonstrate how well the airport can cope with modern passenger jets.
They were fulfilling a pledge made last year at meetings with residents and Folkestone and Hythe MP Michael Howard.
LAA spokesman Robin Gordon said the 737-300 was the noisiest of its marque.
"We have deliberately chosen the 737 with the noisiest engines so that people really understand this is the worst possible case for Lydd," he said.
Protesters said watching the landing was "like waiting for a bomb to come and land on your property".
"It is the industrialisation of Romney Marsh and that is why local people are so passionately opposed to this," said Peter Carroll of Keep the Marsh Alliance.
But supporters of the airport expansion say it would bring welcome jobs and an economic boost to the area.
Protesters gathered to watch the plane fly over the marsh
"I would be quite happy to see 30 flights a day it this is the level of the noise," said Tim Compton of Friends of Lydd Airport.
"It's not too bad - I can live with that very easily."
LAA has submitted two planning applications to Shepway District Council.
One is for a new terminal building to handle up to 500,000 passengers a year - the equivalent of 10 flights a day - the other is for two runway extensions, together 444m (1,456ft) in length.
A public consultation on the plans runs until 5 March.
Lydd Airport Action Group, which opposes the applications, has hired outside consultants to help prepare its response.
It claims the runway extension would allow the airport to increase passenger numbers to two million a year by 2015.
Residents are being urged to write to Shepway Council and the Government Office for the South East objecting to the planning applications and calling for a public inquiry.