Mistake 1
Wrong runway end selected
Directional surfaces and runway-relative offsets are evaluated from the selected threshold. If the runway pair is right but the runway end is wrong, the geometry basis can change materially.
Operational guidance
Common Mistakes
Most first-pass evaluation mistakes come from threshold context, criteria selection, datum inputs, or reading a Clear result too broadly. Use this page as a short pre-export check.
Eight Common Mistakes
Mistake 2
Wrong criteria profile selected
Part 77, FAA AC, and UFC / DoD are separate criteria families. Choose the governing profile for the project instead of assuming one clear result applies across every authority.
Mistake 3
Height entered as MSL instead of AGL
Object height AGL should be the structure height above local ground. If you paste an MSL top elevation into the AGL field, the calculated object top elevation will be wrong.
Mistake 4
Missing or bad ground elevation
Clear Path derives object top elevation from ground elevation MSL plus object height AGL unless you intentionally use an override. Bad ground elevation creates bad obstruction results.
Mistake 5
Coordinates copied in the wrong format
Check sign, decimal format, and whether the copied point is the obstacle location or a nearby reference point. Coordinate mistakes can move the object outside the intended runway context.
Mistake 6
Assuming Clear equals approval
A Clear result means the encoded evaluated criteria at that location did not produce a violation. It does not issue FAA, DoD, airport, engineering, or agency approval.
Mistake 7
Ignoring Needs Review or Not Evaluated
Needs Review and Not Evaluated are real output states. They mean the project still needs follow-on review, missing data resolution, or a criteria path that is outside the current automated scope.
Mistake 8
Using metadata-sparse airports without checking assumptions
Some airports require more manual confirmation than others. If runway metadata, approach profile data, or threshold geometry is sparse, review assumptions before relying on the export.
Final check
Before sharing a report
- Recheck airport, runway pair, and runway end.
- Recheck criteria profile and any runway-specific assumptions.
- Recheck ground elevation, object height AGL, and derived object top elevation MSL.
- Read Needs Review, Not Evaluated, and known-limitations sections before forwarding the report.
Continue with Run Your First Evaluation.