Part 77 Surface & Obstruction Mapping
Model the imaginary surfaces, flag penetrations, and see what is quietly limiting who can serve your field.
Obstructions are the constraint sponsors hear about last and least clearly. A tree line grows. A neighbour builds. A pole goes up outside the fence. Nothing announces itself, and the effect shows up indirectly — in an approach that cannot be lowered, or an operator who quietly stops coming.
What this service is
We model the 14 CFR Part 77 imaginary surfaces over your airport, identify penetrations, and map the departure paths that matter operationally. The output is a layer you can hand to an engineer, show a board, or use when a neighbouring development lands on the county's desk.
A distinction most vendors get wrong
One-engine-inoperative (OEI) surfaces are not a sponsor obligation. OEI obstacle clearance comes from aircraft operator rules under 14 CFR Parts 121 and 135 — it binds the operator, not the airport.
It still matters to you, because obstacles in a departure path constrain which aircraft can use your field at what weight. But if a consultant tells you that you are required to maintain OEI surfaces, they are overstating the rule — and an airport manager who knows the regulations will notice.
What you get
- Part 77 surfaces modelled over current terrain and structures
- A penetration list with location, height and surface affected
- Departure-path analysis showing obstacles that constrain operator performance
- Mapping against parcel ownership, so you know who to talk to about each one
When to run this
Before a development proposal near the airport, before an approach procedure change, and whenever it has been long enough that vegetation has had time to grow. Obstruction data ages quietly.