RF Leg Generator — Radius-to-Fix Arc Between Two Points
Free RF Leg (Radius-to-Fix) generator for maps and KML: enter start and end as lat, lon plus a turn radius in meters, then build a smooth geodesic arc LineString. Copy coordinates or full KML for Google Earth, coverage visuals, and procedure-style paths — not certified aeronautical charting.
Key features
- Start and end pins as decimal lat, lon
- Radius in meters (must be ≥ half the chord length)
- ~48 arc samples for a smooth Earth LineString
- Copy lon,lat coordinates or a ready LineString KML
What RF Leg Generator does
It builds a Radius-to-Fix style arc between two fixes: the tool places a center offset from the chord midpoint, then samples a constant-radius path from start to end. Export the polyline as lon,lat coordinates or a LineString KML for Earth and GIS viewers.
Why map and local SEO teams use it
Draw curved corridors, soft-bound coverage edges, and path visuals that a straight LineString cannot show. Pair with Distance Calculator for chord length and Circle Generator when you need a full ring instead of an arc segment.
Radius vs chord length
Radius must be at least half the great-circle distance between start and end. If you see “radius too small,” increase the radius or move the endpoints closer together.
How to use this tool (best practice)
1) Enter start as lat, lon. 2) Enter end as lat, lon. 3) Set radius in meters (≥ half chord). 4) Generate RF Leg. 5) Copy coordinates or KML. Next: Distance Calculator, Circle Generator, or Segment LineString.
Frequently asked questions
Is this RF Leg Generator free?
Yes. It is free on GBP Local Ranker’s KML Workbench at /free-tools/kml-workbench/rf-leg — no login required for basic use.
What is an RF leg?
In procedure design, a Radius-to-Fix (RF) leg is a curved path defined by a constant radius to a fix. This tool turns that idea into a practical KML arc for visualization — not certified charting.
Is this certified aeronautical procedure design?
No. It is a visualization and export helper for maps and KML. Do not use it as an official IFP or charting product.
What format are start and end in?
Decimal degrees as lat, lon (for example 17.4401, 78.3489). Output coordinates use KML lon,lat order.
Why does it say radius too small?
The radius must clear half the chord between start and end. Use Distance Calculator to measure the chord, then set radius ≥ half that distance.
Which side does the arc bulge?
The center is offset to one side of the chord (perpendicular). If you need the opposite bulge, swap start/end or adjust geometry in Earth after export.
How many vertices are on the arc?
About 48 samples by default, which keeps LineStrings smooth in Google Earth without huge files.
Can I open the result in Google Earth?
Yes — copy the KML block into a .kml file and open it in Google Earth or compatible GIS tools.
How is this different from Circle Generator?
Circle Generator builds a full closed ring around one center. RF Leg builds an open arc segment between two endpoints with a chosen radius.
Where is the full KML Workbench suite?
Open All KML Workbench Tools at /free-tools/kml-workbench for distance, midpoint, destination, bearings, circle generator, and more.