Defence NOC in India: Two Different Clearances, Two Different Authorities

A defence NOC in India is two different clearances: a defence IAF height clearance NOC for sites near military airfields, and an NOC for building near defence establishments like depots and stations. Each has its own rules and authority, and AAI’s NOCAS handles neither.

Which one applies to your plot decides who you apply to, what survey data you need and how long approval can take. This guide explains both, shows the sources we checked, and is honest about where the rules have changed or remain unsettled.

Defence NOC at a glance

1. Is the site near a military airfield? If an Air Force, Navy or other defence aerodrome is close, start with Type A and ask the station for its zoning map.
2. Is the plot near the boundary of a military station, depot or base? If yes, Type B may apply, usually raised through your plan-approval authority.
3. Is there a civil airport nearby as well? Then an AAI NOC may also be needed, and more than one clearance can apply.
4. Not sure? Ask your municipal authority which clearances it needs for plan approval, and share your surveyed coordinates with a surveyor before you finalise the design.

A defence airfield height clearance NOC confirms that the height of a proposed building, tower, chimney or other structure will not interfere with flight paths, radar or navigation aids at a military aerodrome. It matters for buildings as much as for solar projects, wind turbines and mobile towers.

AAI’s NOCAS portal is built for civil airports covered by GSR 751(E), the aerodrome safeguarding notification issued by the Ministry of Civil Aviation on 30 September 2015. AAI’s own application guidelines add that, for defence airports, responsibility has been assigned to the respective defence authorities. A NOCAS approval therefore does not clear a site near a military airfield. Our explainer on what GSR 751(E) covers describes the civil side.

Zoning maps follow the same logic. AAI states that colour coded zoning maps for IAF aerodromes have been prepared and are held by the local stations, so the permissible height near an airbase is something to ask the station about. Our guide to the colour coded zoning map (CCZM) shows how these grids work for civil airports.

What an actual IAF NOC looks like. A publicly filed IAF letter (HQ Western Air Command, 2020, for a group-housing project near Air Force Station Chandigarh) shows the pattern. The application was examined under GSR 751(E) and the Works of Defence Act, 1903, and the NOC covered a building of 82.5 m with conditions:

• it was valid for construction only and could not be used to claim land ownership;
• the applicant stayed responsible for clearances from any other defence establishment nearby;
• coordinates that differed from those declared put the NOC at risk of cancellation;
• it was valid for five years, and revalidation was not entertained after expiry.

These conditions belong to that letter. Treat them as an illustration and read your own NOC line by line.

Survey data. For civil NOCs, AAI’s guidelines ask for WGS-84 coordinates in DD MM SS.s format with position accuracy within 3 metres, and site elevation in metres AMSL within 0.5 metres. A defence station may specify its own format, but this is a sensible baseline. Data errors are among the most common reasons civil applications fail, so read why airport NOC applications get rejected, and our guides to the site elevation survey and the AMSL elevation certificate.

What is an NOC for construction near a defence establishment (Type B)?

This clearance has nothing to do with aircraft. It is about security: keeping sight lines clear and limiting what can be built or overlooked near bases, depots, ordnance sites and similar establishments.

Legal basis. The Works of Defence Act, 1903 lets the Government impose restrictions on land near a notified work of defence. In a reply to Parliament, the Ministry of Defence noted that Section 7 allows restrictions up to 2,000 yards from the crest of the outer parapet. Where no such notification exists, the Ministry has issued executive NOC guidelines instead, first in May 2011 and amended several times since.

How it reaches you. In both the 2011 and the 2022 versions of the guidelines, the Station Commander conveys objections or views to the municipal body or state agency, and not directly to a builder or private party. In practice, your building-plan approval authority tells you whether an LMA view is needed. One Bombay High Court ruling observed that the 2011 circular is a set of guidelines that does not by itself prohibit construction, while other courts have dealt with NOC requirements case by case. If your plot is close to an establishment, take legal advice alongside the technical work.

Why the distances you read online disagree

The 2011 guidelines and their first amendments are on the Parliament record. The position has moved several times since:

This is why we do not quote a single distance on this page. Any fixed figure you see online may belong to a circular that has since been replaced or disputed. Ask the Station Commander’s office or your municipal authority which one applies to your plot.

When other laws take over. The 2022 circular itself says its instructions do not apply where construction is already regulated by another law or notification, such as the Cantonments Act, 2006, aviation-related notifications, or restrictions notified under the Works of Defence Act. In those cases, that law’s rules prevail.

How to find out whether your plot is affected

1. Ask your municipal or planning authority whether plan approval in your location requires the Station Commander’s view.
2. Get a surveyed distance from your plot boundary to the establishment boundary, measured on the ground and not from a web map. A DGPS survey or total station survey gives coordinates and distances that hold up when an authority questions your numbers.
3. Note the number of storeys and the total height. Older guidelines treated buildings above four storeys differently.
4. Check the date of your sanctioned permission. The guidelines exempted permissions issued before 18 May 2011, except later height amendments.
5. If the plot is also near an airfield, check Type A as well.

How does a defence NOC differ from an AAI NOC or DGCA clearance?

For most projects the civil NOC comes from AAI and not from DGCA; see AAI NOC vs DGCA clearance. For civil airports, start with our airport NOC survey services in India and the building height clearance AAI NOC guide.

Documents and survey data: what is usually needed

Treat this as typical, not official. The checklist from the concerned authority always prevails.

The civil side is covered in detail in documents required for an airport height clearance NOC and our NOCAS application documentation guide.

How long does a defence NOC take?

We could not find one published timeline that covers defence NOCs, so we do not quote one. What the sources do say:

• Under the Ministry of Defence guidelines, where municipal law requires consultation, the Station Commander may convey views within four months of receiving the request. In the 2022 text, LMA comments on proposals sitting behind existing high-rise buildings were due within 30 days.
• For civil airports, AAI’s guidelines say an accepted application is processed within 15 working days. See our AAI NOC approval timeline for what happens in practice.

Be cautious with anyone who promises a fixed defence timeline. Timing depends on the station, the file and whether additional review is needed.

Common mistakes that delay a defence NOC

• Assuming an AAI NOC also clears a site near a military airfield.
• Quoting a distance from an old circular without checking which one the LMA is applying now.
• Submitting coordinates or elevation that do not match across the application, drawings and certificates.
• Treating the NOC as proof of land ownership or as transferable to another project.
• Ignoring a second defence establishment in the vicinity.
• Changing height after approval without checking whether a fresh NOC is needed.

What a survey can and cannot do

A licensed survey gives you measured facts that an authority can verify: WGS-84 coordinates, site elevation in metres AMSL, plot boundaries, and the distance from your plot to the nearest defence boundary or airfield reference point. Our teams capture this with DGPS and total station equipment and prepare it in the format your authority asks for.

What we cannot do is issue an NOC, decide which circular applies, or guarantee approval or a timeline. The defence authority makes that decision. If you are not sure whether your site needs a Type A clearance, a Type B clearance or both, talk to our survey team with your plot coordinates and we will tell you what data to prepare before you apply.

Defence and civil zones in the same city

In some cities, military and civil flying sit close together. The IAF letter described above concerned a project near Air Force Station Chandigarh, and a 2023 Bombay High Court case dealt with revalidation of an IAF NOC near the IAF airfield in Pune. Our location pages cover local airports and zones for Pune, Chandigarh and Delhi NCR.