Curv Aero 14 CFR 77.9 Notice Criteria: When You Must File FAA Form 7460-1
Section 77.9 of 14 CFR Part 77 decides one question: does the FAA need to know about your structure before you build it? If the answer is yes, you file FAA Form 7460-1, Notice of Proposed Construction or Alteration, and the FAA runs an aeronautical study. This guide walks through every Part 77 notice criterion in plain English, with the math you need to check a site yourself.
Updated November 7, 2026 · Reflects 14 CFR Part 77 as amended effective October 28, 2026
What 77.9 actually says
Part 77 is the FAA's rule for Safe, Efficient Use, and Preservation of the Navigable Airspace. Subpart B sets the notice requirements, and §77.9 lists what triggers them. The section opens with a catch-all: you must file if the FAA requests it, or if your proposal falls into any of the categories in paragraphs (a) through (d). Paragraph (e) then lists the exceptions.
Notice is a reporting duty, not an approval process. Meeting a criterion does not mean the structure is a hazard; it means the FAA gets to look before it goes up. The hazard question is answered later, in the aeronautical study, using the separate obstruction standards of Subpart C (§77.17) and the FAA's own procedures.
77.9(a): The 200-foot rule
Any construction or alteration more than 200 feet above ground level at its site requires notice. Location does not matter: a 210 ft tower in the middle of a national forest, 60 miles from the nearest runway, still needs a 7460-1.
Height means overall height, including antennas, lightning rods, obstruction lights and any other appurtenance. A 195 ft tower carrying a 10 ft whip antenna is a 205 ft structure.
77.9(b): The notice surfaces around airports and heliports
Closer to an airport, the threshold drops sharply. Paragraph (b) defines a notice surface (not to be confused with the §77.19 imaginary surfaces) that starts at the elevation of the nearest point of the nearest runway and rises outward. If your structure would stick through that surface, notice is required.
| Paragraph | Applies to | Slope | Extends | Rises |
|---|---|---|---|---|
| 77.9(b)(1) | Airport whose longest runway is more than 3,200 ft | 100:1 | 20,000 ft | 1 ft per 100 ft (max 200 ft) |
| 77.9(b)(2) | Airport whose longest runway is 3,200 ft or less | 50:1 | 10,000 ft | 1 ft per 50 ft (max 200 ft) |
| 77.9(b)(3) | Heliport (from the nearest landing and takeoff area) | 25:1 | 5,000 ft | 1 ft per 25 ft (max 200 ft) |
Two details trip people up. First, the slope is measured from the nearest point of the nearest runway, not the airport reference point or the center of the field, so a site beside the middle of a long runway is closer than it looks on a map. Second, the surface is set by elevation, not height above your own ground. A structure on a hill can exceed the surface at a modest AGL height; a structure in a valley can clear it at a surprising one.
Which airports count?
Paragraph (b) applies only to the airports and heliports described in paragraph (d):
- Public-use airports listed in the Chart Supplement (Airport/Facility Directory), the Alaska Supplement or the Pacific Chart Supplement
- Military airports under construction, and airports under construction that will be available for public use
- Airports operated by a federal agency or the Department of Defense
- Any airport or heliport with at least one FAA-approved instrument approach procedure
That last item matters: a private-use field with a published instrument approach brings its own notice surface with it.
A developer wants to put up a 110 ft building. The site is 8,000 ft from the nearest point of a 6,500 ft runway. That runway point sits at 5,400 ft MSL, and the site's ground elevation is 5,380 ft MSL.
- The longest runway is over 3,200 ft, so 77.9(b)(1) applies: 100:1 out to 20,000 ft.
- Surface height above the runway point: 8,000 ÷ 100 = 80 ft.
- Surface elevation at the site: 5,400 + 80 = 5,480 ft MSL.
- Top of the building: 5,380 + 110 = 5,490 ft MSL.
- 5,490 is above 5,480, so the building penetrates the surface by 10 ft. Notice is required.
Drop the building to 95 ft and the top is at 5,475 ft MSL, 5 ft below the surface, and no notice is required under (b). Five feet of design height decides whether you file.
A 60 ft grain leg is planned 2,500 ft from the end of a 2,800 ft public-use runway. Ground elevation and runway elevation are both 1,050 ft MSL.
- The longest runway is 3,200 ft or less, so 77.9(b)(2) applies: 50:1 out to 10,000 ft.
- Surface height: 2,500 ÷ 50 = 50 ft, so the surface is at 1,100 ft MSL.
- Top of the grain leg: 1,050 + 60 = 1,110 ft MSL, 10 ft above the surface. Notice is required.
77.9(c): Roads, railroads and other traverse ways
A road or railroad near an airport is tested as if the traffic on it were part of the structure. You add an allowance for the tallest thing that normally travels it, then run the result against paragraphs (a) and (b).
This is why a new road alignment or rail spur near a runway end can need a 7460-1 even though the pavement itself sits at ground level.
77.9(d): Construction on an airport
Any construction or alteration on one of the airports or heliports listed above requires notice, regardless of height. New hangars, fuel farms, terminal additions, lighting, fencing near movement areas and temporary construction equipment all fall in. On-airport proposals are filed through the same OE/AAA system, as "on airport" cases.
| Traverse way | Add |
|---|---|
| Interstate highway (National System of Military and Interstate Highways, 17 ft overcrossings) | 17 ft |
| Any other public roadway | 15 ft |
| Private road | 10 ft, or the height of the tallest vehicle that normally uses it, whichever is greater |
| Railroad | 23 ft |
| Waterway or any other traverse way | Height of the tallest mobile object that normally uses it |
77.9(e): When you do not need to file
Four exceptions apply:
- 01
Shielding. An object shielded by existing permanent, substantial structures or by terrain of equal or greater height, in the congested area of a city, town or settlement, where the shielded structure won't adversely affect air navigation.
- 02
Functional aviation equipment. Air navigation facilities, visual approach and landing aids, arresting gear and meteorological devices meeting FAA-approved (or military) siting criteria, whose location and height are fixed by their purpose.
- 03
Notice required elsewhere. Construction for which another FAA regulation already requires notice.
- 04
Short antennas. An antenna structure 20 ft or less in height, unless it increases the height of another antenna structure.
Shielding is the exception most often misapplied. It requires all of its conditions, including the congested-area test, and the FAA can disagree with your judgment. When in doubt, file; an unnecessary notice costs time, while a missed one can stop a project.
Timing: the 45-day rule in 77.7
If 77.9 requires notice, §77.7 sets the deadline: at least 45 days before the earlier of the construction start date or the date an application for a construction permit is filed. Many local building departments ask for the FAA determination before issuing a permit, so in practice the clock often starts earlier than the 45 days suggests. FAA aeronautical studies routinely take longer than 45 days, particularly when a structure is circularized for public comment or receives a Notice of Presumed Hazard. For permanent wind energy systems and their met towers, the minimum is 90 days.
Emergency work that can't wait is handled differently: notice goes to the FAA by the fastest available means, followed by a completed 7460-1 within five days.
After you file
The FAA assigns an Aeronautical Study Number and evaluates the proposal against the obstruction standards, instrument procedures, radar and navigation aid performance, and VFR traffic patterns. The outcome is usually a Determination of No Hazard to Air Navigation, which may require marking and lighting under Advisory Circular 70/7460-1 and is typically valid for 18 months unless extended. If the FAA issues a Notice of Presumed Hazard, the sponsor can usually amend height or location to clear it.
Supplemental notice on Form 7460-2 is required under §77.11 for structures more than 200 ft AGL or when the FAA requests it. You file it within the time limits stated in the determination; where none are stated, notice is due within 5 days after the structure reaches its greatest height. Abandoning or dismantling a structure that required supplemental notice also triggers a 5-day notice. See our Part 77 filing service for how we handle the full cycle.
Check your site against 77.9
Enter a coordinate and a structure height. We'll tell you which criterion controls, by how many feet, and whether you need to file.
Frequently asked questions
What height requires FAA notice under Part 77?
More than 200 ft AGL anywhere, under 77.9(a). Near a qualifying airport or heliport, much lower structures can require notice if they exceed a 77.9(b) surface.
Do construction cranes need a 7460-1?
Yes, when they meet a criterion (see our crane guide). Cranes and other temporary equipment are tested the same way as permanent structures, and crane notices are among the most common filings near urban airports.
Does filing mean my structure is a hazard?
No. Notice criteria are a screening threshold, deliberately set lower than the hazard standards. Most notices end in a Determination of No Hazard.
Can the FAA require notice even if I don't meet 77.9?
Yes. The section begins "If requested by the FAA," so the FAA can ask for notice of a proposal that falls outside the numeric criteria.
Is there an official tool?
The FAA's OE/AAA site offers a Notice Criteria Tool that screens a single point. The CurvAero Part 77 Report runs the same tests, shows the controlling runway, distance, surface elevation and margin behind each answer, and carries the result straight into a filing.