An AAI NOC for height clearance is a No Objection Certificate from the Airports Authority of India confirming that your proposed building, tower, solar plant or wind turbine stays within the maximum top elevation allowed at that location. It is mandatory within 20 km of a VFR airport or 56 km of an IFR airport, and it is applied for online on AAI’s NOCAS portal. The certificate is valid for 8 years.

Surveying India prepares the certified site data that NOCAS depends on: WGS-84 coordinates, AMSL site elevation and the supporting drawings. We do this for buildings, telecom towers, transmission lines, solar projects and wind turbines across India.

Last updated: November 2026. Based on AAI’s NOCAS FAQs and the Ministry of Civil Aviation notification GSR 751(E) as amended.

AAI NOC for Height Clearance at a Glance

What Is an AAI NOC for Height Clearance?

An AAI height clearance NOC is written permission that tells you the highest point your structure may reach, expressed as a top elevation above mean sea level (AMSL). It exists to keep approach, take-off and landing paths clear of obstructions.

The certificate is issued for height clearance only. It does not prove land ownership, and it does not replace building plan approval, fire clearance, environmental clearance or any other statutory permission. Your municipality or development authority will still ask for it before approving plans, and RERA registration in many states requires it too.

Who Needs an AAI NOC?

Any person or company planning a structure near an airport needs one. The most common cases are:

• Residential, commercial and industrial buildings (see our guide to building height clearance AAI NOC)
• Telecom and mobile towers (mobile tower airport NOC rules)
• Power transmission lines (transmission tower AAI NOC)
• Solar power plants (solar power project AAI NOC)
• Wind turbines (wind turbine AAI NOC)
• Chimneys, cranes, masts and other tall structures

The distance rule: 20 km, 56 km and 150 m

Distances are measured from the Aerodrome Reference Point of the nearest airport. A site within 20 km of a VFR airport or within 56 km of an IFR airport must be assessed on NOCAS and needs an NOC unless the planned top elevation stays below the CCZM limit. Beyond those limits, a structure below 150 m AGL does not need one, and NOCAS issues a system-generated “NOC not required” letter. To understand which category applies to your airport, read VFR vs IFR airport NOC distance zones.

How AAI Decides Your Permissible Height

Three inputs drive the result:

1. Site coordinates (WGS-84). NOCAS uses your latitude and longitude to place the site against the airport’s surfaces and navigation aids. A wrong decimal can change the answer, which is why certified coordinates matter. See our WGS-84 coordinates certificate for NOC.
2. Site elevation (AMSL). The ground level of your plot above mean sea level. Your permissible height above ground is the allowed top elevation minus this figure. See the AMSL elevation certificate for airport NOC and our site elevation survey.
3. Colour Coded Zoning Map (CCZM). Each airport has a CCZM showing the maximum permitted top elevation by zone. Read our explainer on the colour coded zoning map.

The formula is simple: Height (AGL) = Top elevation (AMSL) − Site elevation (AMSL). If your planned top elevation sits below the CCZM limit, NOCAS can confirm that no NOC is needed. If it sits above, AAI examines the case.

How to Apply for an AAI NOC: Step-by-Step

The full walkthrough is in our NOCAS portal application process guide. In summary:

1. Check the CCZM and distance. Confirm whether your plot falls inside the 20 km or 56 km zone and what top elevation the CCZM allows.
2. Get the site survey done. A qualified surveyor records WGS-84 coordinates and AMSL elevation using DGPS or Total Station equipment and issues the certificates.
3. Register on NOCAS. Create the applicant account on the AAI NOCAS portal.
4. Fill in the application. Enter site details, coordinates, site elevation, structure type and requested height.
5. Upload documents. Scanned copies of the certificates, plans, ownership proof and the undertaking and authorisation forms go online.
6. Respond to queries. If AAI raises a remark, usually about mismatched coordinates or documents, answer promptly or the file stays pending.
7. Download the NOC. Issued NOCs are downloaded from NOCAS.

Our team handles steps 1, 2 and the document preparation. Full details of the paperwork are in NOCAS application documentation.

Documents Required for AAI Height Clearance NOC

Document rules vary slightly by structure, so use the full list in documents required for airport height clearance NOC. The core set is:

For alterations to an existing structure, attach the earlier NOC.

How Long Does an AAI NOC Take, and How Long Is It Valid?

Timeline. Per AAI’s circular ADSAC 02 of 2024, document checking takes about three working days, NOC committee clearance about five, and issuance about five more once the committee agrees. Real cases take longer when AAI raises queries or the site needs an aeronautical or shielding study. See our AAI NOC approval timeline page for realistic ranges.

Validity. Eight years from the date of issue, per the AAI NOCAS FAQs. Revalidation is possible in defined cases, such as when construction has begun and the delay was beyond the applicant’s control.

Cost. AAI does not charge a filing fee for a standard height clearance NOC on NOCAS, according to current guidance. Your costs are the survey, documentation and any consultant fees. An appeal to the Appellate Committee carries its own fee.

Why AAI NOC Applications Get Rejected

Most rejections and delays trace back to avoidable data errors:

• Coordinates that do not match the plot or the layout drawing
• Site elevation recorded with the wrong datum or without a proper survey
• Requested height above the CCZM limit with no shielding justification
• Missing authorisation or undertaking forms
• Applying after construction has started

Read the full list in airport NOC rejection reasons. If AAI refuses your requested height, you may appeal to the Appellate Committee, and a fresh, accurate survey is usually the first thing worth rechecking.

AAI NOC vs DGCA vs Defence NOC

These are separate clearances and are often confused:

• AAI NOC controls height near civil airports. Compare it with DGCA in AAI NOC vs DGCA clearance.
• Defence / IAF NOC is needed when your site falls within the jurisdiction of a defence airfield. AAI’s NOC letters themselves note that a separate Defence NOC is required in such cases. See Defence IAF height clearance NOC, Defence NOC India and Defence NOC vs AAI NOC.
• Local military authority NOC applies near cantonments. See army cantonment construction NOC and defence establishment construction NOC.

The legal background is covered in GSR 751(E) airport NOC rules explained.

AAI NOC by Structure Type

• Buildings: Building height clearance AAI NOC and building height restrictions near airports
• Towers and lines: Mobile tower airport NOC and transmission tower AAI NOC
• Solar: Solar power project AAI NOC and solar farm height clearance
• Wind: Wind turbine AAI NOC and wind turbine height limits near airports

Airport NOC Survey Services by City

We provide on-ground survey and NOC documentation support in these cities:

Delhi NCR · Mumbai · Bengaluru · Pune · Ahmedabad · Surat · Dholera · Jaipur · Kota · Lucknow · Varanasi · Patna · Chandigarh · Bhopal · Indore · Nagpur · Raipur · Guwahati

For the complete overview of our service, see airport NOC survey services in India.

Why Choose Surveying India for AAI NOC Survey Support

• Survey-first accuracy. Our DGPS and Total Station surveys produce WGS-84 coordinates and AMSL elevations that match what NOCAS expects, which cuts down on AAI queries. (Add: instruments used and accuracy standard.)
• Every structure type. Buildings, towers, transmission lines, solar and wind projects. (Add: number of NOC projects delivered.)
• Pan-India coverage. City teams across north, west, central, east and south India. (Add: states covered.)
• Clear scope. We deliver the technical certificates and documentation; ownership and approval documents come from you. (Add: team credentials and surveyor licence details.)
• Defence and AAI under one roof. We guide you on when a Defence or IAF NOC is also needed.

Get your site surveyed for an AAI NOC. Share your plot location and planned height, and our team will confirm whether an NOC applies and what survey data you need. (Add: call button, WhatsApp link and enquiry form.)