Frequently Asked Questions
Answers to the questions we hear most from planners evaluating AvPlot. Something not covered here? Email us — a real person reads it.
AvPlot is a web-based airport planning decision engine. It replaces the manual FAA Advisory Circular lookup → spreadsheet → CAD drafting workflow with purpose-built tools: runway linework generation, taxiway fillet geometry, design-standard references (RSA, ROFA, RPZ, separations), aircraft classification, declared distances, coordinate conversion, and more. Every output carries a citation trail back to the governing FAA source so your numbers are defensible.
Airport planners, engineering consultants, and airport authorities. It is built as an expert power tool for people who already know what they want — senior planners who need speed and accuracy, not guided hand-holding.
No. AvPlot is an independent product and is not affiliated with, endorsed by, or sponsored by the Federal Aviation Administration or any other government agency. FAA publications and data are referenced only as the public standards the software consults.
Two primary sources:
- FAA NASR (National Airspace System Resources) — authoritative airport, runway, and navaid facts, refreshed on the FAA's 28-day data cycle. Every record carries its cycle date so citations are traceable.
- AC 150/5300-13B (Airport Design) — the governing standard for design dimensions: RSA, ROFA, RPZ, taxiway separations, fillet geometry, and design-group classifications.
For facilities NASR doesn't cover (non-US airports), community data from OurAirports is used as a clearly-labeled fallback.
AvPlot outputs are planning reference only — production support for planning studies, design reports, and ALP narratives. They are not construction documents and not a substitute for stamped engineering work. Always verify against the current FAA publications before relying on any value; the citation trail is there to make that verification fast.
DXF (CAD linework), KMZ (Google Earth), XLSX (data tables), and CSV (tabular results), depending on the tool.
Use the feedback form or email support@avplot.com with what you saw, what you expected, and the tool you were using. Bug reports with inputs that reproduce the issue get fixed fastest.
No free tier. New accounts get a 14-day trial, and beta users receive a founding-member discount when paid plans launch.
All modern evergreen browsers (Chrome, Edge, Firefox, Safari). Chrome is recommended — it is the primary test target.
Which AvPlot tool answers my question?
Every AvPlot tool maps to a question planners ask the FAA standards. Each answer traces back to AC 150/5300-13B or the cited FAA source.
Select the Airplane Design Group and approach visibility, and AvPlot returns the Runway Safety Area and Runway Object Free Area dimensions from FAA AC 150/5300-13B Appendix G. For ADG III the RSA is 500 ft wide extending 1,000 ft beyond each runway end, and the ROFA is 800 ft wide. Every value carries its FAA citation.
For approaches with minimums below 3/4 statute mile, the Runway Protection Zone is 2,500 ft long with a 1,000 ft inner width and 1,750 ft outer width (78.914 acres). Runways with 3/4-mile-or-greater minimums use 1,700 by 1,000 by 1,510 ft (48.978 acres), per AC 150/5300-13B Appendix G.
Identify the critical aircraft using the runway, then read its Airplane Design Group (ADG, by wingspan) and Taxiway Design Group (TDG, by main-gear and cockpit-to-main-gear geometry). AvPlot returns both from the aircraft type per AC 150/5300-13B.
Enter runway length, displaced thresholds, stopway, and clearway per end, and AvPlot computes all four declared distances per AC 150/5300-13B Appendix H. TORA is the takeoff ground run, TODA adds clearway, ASDA adds stopway, and LDA is the landing length after any displaced threshold.
Round the runway's magnetic azimuth to the nearest 10 degrees and drop the trailing zero, so 174 degrees becomes Runway 17 and its reciprocal is Runway 35. AvPlot derives both ends using NASR magnetic variation.
Enter the runway endpoints and design parameters, and AvPlot generates centerline, edges, threshold markings, and blast pads as scaled CAD geometry per AC 150/5300-13B. Export as DXF for CAD or KMZ for Google Earth, with an optional 3D DXF that adds Part 77 surfaces.
One-half statute mile equals Runway Visual Range (RVR) 2400. Other common equivalents are 1/4 SM = RVR 1600, 3/4 SM = RVR 4000, and 1 SM = RVR 5000, per the standard FAA conversion table.
Enter each runway's end coordinates and AvPlot computes the length-weighted centroid, the standard FAA method for the Airport Reference Point per AC 150/5300-13B paragraph 1.8.1. Longer runways pull the ARP toward their midpoints.
Enter a latitude and longitude or airport location and AvPlot returns the State Plane Coordinate System zone, its projection type, and the EPSG code for that point, so your survey and CAD linework tie to the correct NAD83 grid.
Select the Taxiway Design Group and intersection turn angle, and AvPlot computes the fillet radius and taper geometry using the cockpit-over-centerline method per AC 150/5300-13B Appendix J. The R-fillet value is 0 ft for turns of 90 degrees or less. Output is a ready-to-use DXF.
Required separations between runway centerline and parallel taxiway centerline, and between taxiways and objects, vary by Airplane Design Group and approach visibility. For ADG III the runway-to-parallel-taxiway centerline separation is 400 ft per AC 150/5300-13B.
Enter obstacle coordinates and elevations with the runway data, and AvPlot evaluates each point against the 14 CFR Part 77 imaginary surfaces and the AC 150/5300-13B obstacle clearance surfaces, flagging penetrations. Results export as a layered DXF for the ALP.
Provide the tower cab location and height with the points to observe, and AvPlot evaluates unobstructed line-of-sight, lateral discrimination, minimum cab height, and shadowing per FAA Order 6480.4C. Results export as CSV, DXF, or KMZ.
AvPlot's Airspace Surface Reference returns the applicable 14 CFR Part 77 imaginary surfaces and the TERPS and AC 150/5300-13B approach surfaces by runway type and approach, so you can see which evaluation airspace governs each end.
AvPlot overlays your parcel boundaries on the airport property and works through the Appendix B checklist for the Exhibit 'A' Property Map per FAA ARP SOP 3.00, capturing each land interest and how it was acquired.
Enter the airport (NASR auto-fill by identifier) or runway data, and AvPlot generates the Airport Data, Runway Data, and Declared Distance tables as XLSX or DXF per FAA ARP SOP 2.00 Appendix A.3, with existing and ultimate columns.
Upload the airport's Terminal Area Forecast data and choose trend, market-share, or regression methods; AvPlot produces operations and based-aircraft forecasts with the FAA TAF consistency check per AC 150/5070-6B and the August 2024 APP-400 memo.
Search the Aircraft Library by type designator to see its Aircraft Approach Category, Airplane Design Group, Taxiway Design Group, and maximum takeoff weight per AC 150/5300-13B.
Planning, standards & the ALP
Background on the FAA standards and the planning workflow behind the tools.
There is no fixed calendar interval, but the FAA expects the ALP to remain current and recommends review on roughly a 5-to-10-year cycle, typically alongside a master plan update. It must be updated whenever a planned or completed change makes the drawing no longer reflect the airport.
An ALP update is triggered by any change to airport facilities or design standards: a new or extended runway or taxiway, a change in critical aircraft or design group, revised RPZ or safety-area geometry, new development on airport property, or a change required for an AIP grant.
The critical (design) aircraft is the most demanding aircraft, or group of aircraft with similar characteristics, that makes at least 500 annual itinerant operations at the airport, excluding touch-and-go, per FAA AC 150/5000-17. Its approach speed and dimensions set the runway's design code.
The Runway Design Code combines the Aircraft Approach Category (a letter from approach speed), the Airplane Design Group (a Roman numeral from wingspan and tail height), and the approach visibility minimum. It is set by the runway's critical aircraft and drives nearly every runway design dimension per AC 150/5300-13B.
The RPZ should be clear of incompatible land uses. The FAA discourages residences, fuel storage, places of public assembly, and wildlife attractants; compatible uses such as agriculture, some roads, and parking may be acceptable only with FAA coordination. The central RPZ should remain free of all above-ground objects.
Part 77 imaginary surfaces define obstruction-evaluation airspace used for notice (Form 7460-1) and ALP depiction. TERPS surfaces, from FAA Order 8260.3, protect actual published instrument approach procedures and are generally steeper and procedure-specific. A structure can clear Part 77 yet still affect an instrument procedure.
Use the standard FAA conversion: 1/4 SM = RVR 1600, 1/2 SM = RVR 2400, 3/4 SM = RVR 4000, and 1 SM = RVR 5000. RVR is reported in feet by touchdown-zone sensors and governs lower-visibility approaches.
The governing standard is AC 150/5300-13B, Airport Design, supported by 14 CFR Part 77 (imaginary surfaces), FAA Order 8260.3 (TERPS), AC 150/5000-17 (critical aircraft), AC 150/5070-6B (master planning and forecasts), and the ARP Standard Operating Procedures for the ALP and Exhibit 'A'.