Airport NOC Survey & AAI Height Clearance Services in India
We handle every stage of the Airport NOC process — certified site coordinates, OLS analysis, and NOCAS filing — so construction near an airport can proceed without avoidable delay.
Talk to a survey expert →Airport NOC Survey, defined
An Airport NOC Survey establishes the certified coordinates, ground elevation (AMSL), and proposed structural height of a site near an airport. This data is the technical basis for an NOC application filed with the Airports Authority of India (AAI) through the official NOCAS portal.
Our process also covers Obstacle Limitation Surface (OLS) analysis, Colour Coded Zoning Map (CCZM) interpretation, and documentation prepared in the format AAI's regional NOC cells expect — reducing the chance of rejection at first submission.
The most common cause of rejection is inaccurate GPS coordinates or elevation data. We use RTK-GNSS survey-grade instruments for precision within ±5 cm.
Who needs an Airport NOC, and at what distance
Applicability depends on three things: how far the site is from the Aerodrome Reference Point (ARP), what type of airport it is, and the proposed height of the structure. The table below summarises the core thresholds under GSR 751(E).
| Airport type | NOC-applicable radius from ARP | Typical examples |
|---|---|---|
| IFR aerodrome (instrument-rated) | 56 km | Delhi (IGI), Mumbai, Bengaluru, Hyderabad, Chennai and other major international/domestic airports |
| VFR aerodrome (visual-rated) | 20 km | Smaller domestic airports, flying clubs, some state-owned airstrips |
| Defence aerodrome | Case-specific, set by MoD | Air Force stations, Army/Navy airfields — NOC issued separately by the aerodrome operator |
| Helipad | Site-specific, per operator | Private and government helipads with their own obstacle-limitation criteria |
Structures that typically require an NOC:
- Buildings and residential towers — including proposed additional floors on existing structures
- Telecom and broadcast towers — mobile network towers, TV/radio masts, OFC poles above threshold height
- Industrial chimneys and stacks — factory chimneys, cooling towers, flare stacks
- Transmission lines and power infrastructure — high-tension towers, wind turbines, solar farm structures
- Cranes and construction equipment — tower cranes operating above permissible height during construction
- Hoardings and billboards — large outdoor advertising structures near flight paths
Understanding the Colour Coded Zoning Map (CCZM)
AAI publishes a CCZM for each airport, dividing the surrounding area into colour-coded zones based on permissible construction height. Our survey identifies which zone your site falls in before any application is filed.
| Zone | Meaning | What it means for you |
|---|---|---|
| Green | Height stays below the permissible elevation for that grid | NOC is generally not required, subject to confirmation |
| Yellow | Height is close to or borderline with the permissible limit | NOC application required; approval depends on precise survey data |
| Red | Height exceeds the permissible elevation for that grid | NOC likely to be restricted or rejected at proposed height; height reduction may be needed |
Documents required for filing
NOCAS applications are scrutinised closely — incomplete or inconsistent documentation is the second most common reason for delay, after inaccurate survey data. Here's what's typically needed:
- Certified GPS coordinates in WGS-84 format, captured by RTK-GNSS survey
- Site elevation certificate (AMSL) prepared and signed by a licensed surveyor
- Structural drawings showing proposed height, floor plans, and elevation views
- Site plan with surrounding context and access details
- Land ownership documents or lease deed establishing the applicant's right to the site
- Authorization letter, if the applicant is not the registered owner
- Signed NOCAS declaration undertaking compliance with height restrictions
- Applicable fee payment confirmation as per AAI's current fee schedule
NOC validity and what happens if you skip it
| Structure type | Typical NOC validity |
|---|---|
| Buildings and towers | Up to 8 years |
| Masts, chimneys, transmission towers | Up to 12 years |
| Cranes and temporary construction equipment | Duration of construction, renewable |
Airport NOC Survey services
GPS coordinate certification
RTK-GNSS surveys delivering WGS-84 coordinates at ±5 cm accuracy, the standard NOCAS requires.
AMSL elevation survey
Certified elevation reports accepted by CPWD, State PWD, AAI, and other regulators.
OLS survey
Obstacle Limitation Surface analysis per ICAO Annex 14, checking for airspace infringement.
NOCAS filing assistance
Documentation and portal filing handled end to end by our regulatory team.
Defence airport NOC
Surveys for structures near Ministry of Defence aerodromes, a separate application track.
NOC revalidation & appeals
Support for revalidation, height revision, and appellate committee filings.
Our process
Site feasibility check
Distance from the nearest ARP, airport type (VFR/IFR), and CCZM review to confirm whether an NOC is required.
RTK-GNSS survey
On-site capture of WGS-84 coordinates and AMSL elevation at centimetre-level precision.
OLS analysis
Structure height checked against Obstacle Limitation Surfaces per ICAO Annex 14.
Documentation
Elevation certificate, coordinate certificate, site plan, and declaration prepared in AAI's required format.
NOCAS filing
Application submitted and tracked through AAI's regional NOC cell.
Approval & compliance
Guidance on obstruction lighting, day-marking, and NOC validity (up to 8 years for buildings, 12 for masts/chimneys).
Authorities we work with
Airport NOC Survey, city by city
Local teams, local airport familiarity. Choose your city for details specific to that jurisdiction's NOC requirements.
Also serving Delhi NCR, Mumbai, Bengaluru, Hyderabad, Chennai, Kolkata, Pune, Kochi, Nagpur, Indore, Patna, Guwahati, and all Tier-2 cities across India.
Airport NOC Survey FAQ
Planning a project near an airport?
Send us your site location and proposed height — we'll tell you within a day whether an NOC applies, and what it will take.