Building or using a crane near Northfield (N09)?
Northfield in Thomaston, Connecticut is a public-use heliport. Under 14 CFR 77.9, anything within 5,000 feet of it that rises above a 25:1 slope needs FAA Form 7460-1 at least 45 days before construction. Check your exact site free.
No address handy? Try 16700 Saticoy St, Van Nuys, CA 91406
How tall can you build near N09 without filing?
The notice surface rises 1 foot for every 25 feet of horizontal distance from the nearest point of the heliport, starting at the heliport's elevation. Using the lowest facility elevation, 903 ft above sea level:
| Distance from heliport | Notice required above (height over 903 ft) | …which is this elevation (AMSL) |
|---|---|---|
| 250 ft | 10 ft | 913 ft |
| 500 ft | 20 ft | 923 ft |
| 1,000 ft | 40 ft | 943 ft |
| 2,000 ft | 80 ft | 983 ft |
| 3,000 ft | 120 ft | 1,023 ft |
| 5,000 ft | 200 ft | 1,103 ft |
| Beyond 5,000 ft | Only the 200-ft-above-ground rule applies (77.9(a)) | |
If your ground is lower than 903 ft you can build taller by the difference; if it's higher, less. Cranes count at their maximum height. The free check above uses USGS ground elevation for your exact spot.
Heliport location and notice boundary
Dashed line: the 5,000-ft area where the 25:1 notice slope applies.
Filing Form 7460-1 near N09
- File online through the FAA's OE/AAA system at least 45 days before construction or before applying for a building permit, whichever is first. Filing is free.
- You need NAD 83 coordinates, site ground elevation, structure height above ground and above sea level.
- Construction on airport property always needs notice, whatever the height.
More: Do I need to file Form 7460-1? · Cranes and Form 7460-1
Other public-use airports nearby
- 4B8 — Robertson Fld (11 nm)
- OXC — Waterbury-oxford (15 nm)
- 6Y2 — Candlelight (18 nm)
- 11N — Candlelight Farms (18 nm)
- MMK — Meriden Markham Muni (18 nm)
- 4B9 — Simsbury (19 nm)
Source: FAA airport, runway and runway-end data (NASR cycle effective 2026/10/01). Screening only — the FAA issues determinations.