Blog · September 30, 2026
What Is an Avigation Easement?
An avigation easement gives an airport the right to have aircraft fly through the airspace above a parcel, often with stated heights, and usually with a tolerance for noise and vibration. It burdens the air above the lot. It is not a deed of the lot to the airport.
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Flight at a defined height
Airports acquire avigation easements in approach paths so trees, roofs, and later buildings cannot rise into the zone the runway needs, and so owners cannot sue for the ordinary noise of operations the easement describes. The document may limit structures above a slope, such as a certain ratio outward from the runway, or above a listed elevation. That slope is the heart of the easement. A lot can be perfectly buildable below it and still be a bad place for a tall shed. Read the height limit before you read the noise paragraph. The noise paragraph explains what you cannot enjoin. The height paragraph explains what you cannot build. They are related and they are not the same sentence.
How it appears in a subdivision file
A plat note may say subject to avigation easement recorded as an instrument number, or the easement may appear only in the title commitment. The plat of lots does not erase it. A blank county GIS map does not erase it either. Airport zones sometimes appear as a separate overlay and sometimes do not appear in the parcel viewer at all. Platbookmapper links to the county GIS and does not draw airspace slopes, zip codes, or non-U.S. aviation charts. Pull the instrument. If you are planting tall trees or putting a tower on the lot, the slope math is survey and airport work, not a phone-altitude check. A phone is not a survey and its elevation is not the easement datum.
What the owner keeps
You keep the fee. You can live on the lot, sell it, and build what the easement and the zoning both allow. You do not get to raise the approach surface because the airport has been quiet for a month. You also do not have to grant a new easement if one is already recorded. If none is recorded and the airport asks for one, that is a conveyance, and it deserves the same reading as any other grant of a property right. Do not sign it because a sketch looks like the flight path you already see. Read the heights. And do not trim a neighbor’s trees under a claim that you are enforcing the airport’s easement. You are not the holder.
What to do next
- Find the instrument and the height or approach slope.
- Separate the noise waiver from the building-height limit.
- Check zoning height limits as a second constraint, not as a substitute.
- Do not use a phone elevation to clear a proposed roof.
The mix-up to avoid
Confusing an avigation easement with ownership of the land. The airport bought a flight right and often a height limit. The lot owner still owns the ground.
Questions people ask
Does the easement let planes fly at any height?
No. It is limited by its terms and by general aviation law. The easement’s own minimum elevation or slope is what you read on the instrument. Lower flight than the grant allows is a different complaint, and it is not something you measure with a camera and a fence post.
Will the tax map show it?
Usually not as a lot line. Some counties have an airport overlay. An overlay is a planning map. The easement is the recorded burden. Read the easement even if the overlay is absent, and do not treat the overlay as the grant.
Find the county map
Open Platbookmapper and pick the county that taxes the land. Use that viewer to get the parcel id, then match it to the recorded plat if you need the easements and lot numbers.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.