They added that a fresh "check survey" would be carried out by the GMR-led Delhi International Airport Limited (DIAL) later this year to validate the findings of another survey conducted two years ago, which had identified 365 structures obstructing the flight path.
Most of these structures were in the form of permanent buildings and the only way to address the issue was through mitigation, the sources said.
For example, it could be done by fixing a light atop a building or modifying the building structure, they added.
"Our obligation is to identify the obstacles and ask the competent authorities such as the Airport Authority of India (AAI) to notify them," a source said.
As a first step, DIAL is serving notices to various erring parties, while both DGCA and DIAL are working to remove the obstacles that are beyond the airport premises.
"We are governed by the International Civil Aviation Organisation (ICAO) and deviations from guidelines are taken seriously. It is the same here," a source said.
DIAL is also reaching out to individual households and keeping a track of the construction in the surrounding areas of the airport.
According to the guidelines, there should be no high-rise buildings within the approach funnel of any airport in order to provide a safe glide path to aircraft. But unauthorised constructions have become a major issue around airports not only in Delhi, but in other cities as well.
No-objection certificates (NOCs) were obtained through manipulation in the absence of clarity as regards the height of the buildings falling on the flight path, an AAI official said.