Guide · FAA Form 7460-1
Do I need to file an FAA Form 7460-1?
If you're building anything tall — a tower, crane, rooftop addition, solar array on a structure, or a mid-rise near an airport — there's a good chance the FAA wants to hear about it first. Here's a plain-English read on when notice is required, what the rules actually say, and how to find out where you stand before you file.
The short answer
Under 14 CFR Part 77, Subpart B (§77.9), you must file a Notice of Proposed Construction or Alteration (Form 7460-1) when your project is:
- More than 200 ft above ground level (AGL) — anywhere, regardless of how far from an airport you are.
- Within 20,000 ft of a public-use airport that has at least one runway longer than 3,200 ft, and taller than an imaginary surface sloping 100:1 outward from the nearest point of that runway. (At 20,000 ft, that's about 200 ft of allowance — closer in, far less.)
- Within 10,000 ft of a public-use airport whose longest runway is 3,200 ft or shorter, and taller than a 50:1 slope.
- Within 5,000 ft of a public-use heliport and taller than a 25:1 slope.
- On an airport, or any height the FAA specifically requests notice for (including certain traveling/temporary equipment like cranes).
If any of these is true, you file. The catch: the sloped-surface tests depend on your exact location, ground elevation, and the airport's runway geometry — which is precisely what's tedious to work out by hand and easy to get wrong.
What "Part 77 penetration" actually means
Part 77 also defines a second, related set of imaginary surfaces(primary, horizontal, conical, approach, and transitional) used to judge whether an object is an obstruction to air navigation. The 150-ft horizontal surface, the 20:1 conical surface, and the long approach surfaces are the ones structures most often break. Penetrating a surface doesn't automatically mean "Hazard,"but it does mean the FAA will study your structure more closely — and it's the single best early signal that a project may need to change height, location, or massing.
Notice criteria vs. line-of-sight — two different questions
There are really two questions worth answering before you file:
- Do I trip a Part 77 surface? A geometric test against the imaginary surfaces above.
- Do I block the control tower's line of sight to a runway? A terrain- and curvature-dependent question the FAA's free notice-criteria tool doesn't evaluate at all, but one that can drive a Hazard determination near towered fields.
The free FAA OE/AAA "Notice Criteria Tool" answers a narrow version of the first question — and only after you submit. It won't tell you about tower line-of-sight, and it won't model terrain or earth curvature.
How to screen before you file
This is the gap LOS Analyzer fills. Enter an airport and your proposed structure, and it computes both Part 77 surface penetration and terrain-aware tower line-of-sight in minutes, then generates a Form 7460-1 draft from the same inputs. A single screening is $499 — versus the $5,000–$15,000 and multi-week turnaround of a full airspace study — so you can catch problems while changing the design is still cheap.
LOS Analyzer is a preliminary screening to inform whether and how to file. It is not a substitute for an official FAA determination or for review by a licensed professional engineer.
FAQ
Is a 7460-1 the same as an FAA permit?
No. A 7460-1 is a notice, not a permit. It triggers an FAA aeronautical study that ends in a Determination of No Hazard or a Determination of Hazard. The FAA does not grant or deny permission to build — that's a local zoning matter — but a Hazard determination can block financing, FCC/utility approvals, or local entitlements.
What happens if I skip it?
Failing to file when required can lead to enforcement, forced modification or removal of the structure, and problems with lenders and insurers. For tall structures it can also create an unmarked hazard to aircraft. When in doubt, screen first and file.
How long does the FAA study take?
A routine study can take from a few weeks to several months depending on complexity, circularization, and whether the structure penetrates obstruction standards. Screening before you file helps you avoid surprises and design out penetrations early.
Find out where your site stands
Screen Part 77 surfaces and tower line-of-sight, then generate your 7460-1 draft.
Start your screening — $499