RSA / ROFA / ROFZ Reference — Tool Guide

Live AC 150/5300-13B CHG 1 · APPENDIX G · ALL GUIDES

The RSA / ROFA / ROFZ Reference returns Runway Safety Area and Runway Object Free Area dimensions — width, length beyond the runway end, and length prior to threshold — for any combination of Aircraft Approach Category group, Airplane Design Group, fleet class, and approach visibility minimum, per AC 150/5300-13B Appendix G. Every value is fetched live from AvPlot's standards engine, which serves the Runway Design Standards Matrix, so each result carries its citation rather than relying on a spreadsheet you have to keep current.

It replaces the usual workflow of pulling the AC, finding the right design-standards table, and working out by hand where each boundary falls relative to declared distances — including which end anchors which length.

Open the RSA / ROFA / ROFZ tool →

Who It's For & When to Use It

Airport planners producing ALP narratives, design reports, and planning studies that document safety area and object free area dimensions. Use it when you need the controlling RSA or ROFA for an existing or proposed runway, when checking how a visibility-minimum or design-aircraft change moves the boundaries, when locating boundaries against a runway end's declared distances, or when you need a defensible citation for a dimension in a report.

How to Use It

  1. Select the Approach Category group. A/B or C/D/E, based on the critical design aircraft's approach speed. The tool lands with a common heavy-fleet lookup pre-selected so results appear immediately; change any input to your case.
  2. Select the Airplane Design Group (ADG). I–VI, based on the design aircraft's wingspan and tail height. Only the ADGs valid for the selected approach-category group are offered.
  3. Pick the fleet class if it applies. Small (≤ 12,500 lb) versus Large — this selector applies to A/B groups in ADG I–II only, where small-aircraft-exclusive runways use reduced standards. For all other combinations it is inactive.
  4. Set the approach visibility minimum. Visual, not lower than 1 mile, not lower than 3/4 mile, or lower than 3/4 mile.
  5. Read the results cards. RSA and ROFA each get a card showing width, length beyond the runway end, and length prior to threshold, with the governing standards group named. The citation line under the results states the measurement anchors: RSA lengths anchor to the ASDA end and LDA threshold; ROFA lengths to the TORA end and LDA threshold.
  6. Check the plan view. A scaled diagram draws the runway with the RSA boundary solid and the ROFA boundary dashed, both ends rendered with identical conditions.
  7. Apply declared distances (optional). Expand the declared-distances section and enter TORA, TODA, ASDA, and LDA for a runway end — or calculate them from physical length, displaced threshold, stopway, and clearway — to see exactly where the RSA and ROFA boundaries fall, overlaid on the plan view.
  8. Copy or share. The copy button puts the full dimension set on the clipboard with its source citation. The URL updates as you work (?aac=&adg=&vis=), so the address bar is always a shareable link that restores the configuration.
  9. Browse the reference table. The complete reference lists all 48 combinations served by the standards engine, filterable by AAC, ADG, and visibility; clicking a row loads it as the current selection.

Key Features

  • Asymmetric-end guidance built in. The results carry a standing note: when the two runway ends differ, look up each end independently and apply the larger width across the full runway — RSA and ROFA are each one continuous surface, so width is runway-governing while length values remain end-specific. The reference notes expand on this.
  • Declared-distance overlay. Boundary positions computed against TORA/TODA/ASDA/LDA for a runway end, drawn onto the plan view — with a calculator that derives declared distances from physical runway inputs if you don't have them on hand.
  • Filterable reference table. All 48 combinations, filterable by AAC group, ADG, and visibility tier, with click-to-select rows and the current selection highlighted.
  • Reference notes. Built-in disclosures covering RSA/ROFA definitions, measurement references, and asymmetric-end handling — useful language when drafting narratives.
  • Shareable URLs and session persistence. Tool state is mirrored into the query string with history.replaceState, and inputs and table filters are saved locally and restored on return. Other AvPlot tools can deep-link in with AAC/ADG/visibility pre-selected.
  • Citation trail. Dimensions come from the standards API, not values hardcoded in the page, and every result and table view carries its Appendix G source.

FAA References

  • AC 150/5300-13B Chg 1, Airport Design — governing standard; RSA and ROFA dimensions per the Runway Design Standards Matrix (Appendix G, Tables G-1 through G-12).
  • Measurement anchors follow the same AC: RSA length beyond the runway end is measured from the ASDA end, ROFA length from the TORA end, and length prior to threshold from the LDA threshold.

Limitations & Disclaimers

AvPlot is technical planning production support — accurate enough for design reports, planning studies, and ALP narratives. It is not a replacement for stamped engineering or construction documents. As the tool itself states: verify all values against current FAA publications before use in official Airport Layout Plans or regulatory submittals.

  • The tool reports a single approach condition; runways whose two ends differ must be looked up once per end, with the larger width applied runway-wide.
  • It reports standard dimensions; it does not evaluate RSA determinations, modifications of standards, or alternatives under FAA RSA policy.

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Tips & Best Practices

  • Start from the design aircraft, not the category: look the aircraft up in the Aircraft Classification Library and carry its AAC/ADG here, rather than recalling categories from memory.
  • For runways with different conditions at each end, run the lookup once per end and apply the larger width across the full runway — the tool's asymmetry note states the rule, but the per-end lookups are yours to run.
  • Use the declared-distances overlay before siting anything near a runway end — the boundaries anchor to ASDA, TORA, and LDA, not to the physical pavement end, and displaced thresholds move them.
  • Copy the URL into your project notes; it documents the exact configuration behind the numbers you cited.
  • Use the reference table's filters when writing alternatives sections — it shows how the dimensions change across visibility tiers and design groups without re-running the selector.

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