AC 150/5300-13B Change 1: What Actually Changed

What Change 1 is — and isn’t

Change 1 is a consolidated change: the FAA reissued the full AC with Change 1 merged in, dated 8/16/2024 on the cover and 3/31/2022 on the consolidated body. There are 41 principal changes listed in the front matter. Most are clarifications, expanded explanations, and editorial cleanups. A smaller set — the ones below — actually alter classification logic, delete tables, or revise dimensional standards. If you maintain spreadsheets, CAD standards, or templates keyed to 13B, those are the items to reconcile.

The headline: Taxiway Design Groups were simplified

The most consequential change for everyday work is item 2: “Simplified Figure 1-1, Taxiway Design Groups, and added Table 1-4 to clarify.” In the 2022 edition, the TDG chart (Figure 1-1) carried diagonal boundary lines that mixed Cockpit-to-Main-Gear (CMG) and Main Gear Width (MGW) into sloped cutoffs. Change 1 removed those diagonals and added Table 1-4, which expresses TDG as clean rectangular CMG and MGW ranges.

Practically: a TDG is now determined by reading an aircraft’s MGW and CMG against the rectangular ranges in Table 1-4 — no diagonal wb/(mgw−20) or (wb−34)/(mgw−30) test. If you still rely on the FAA ADG/TDG classification spreadsheet, note that it predates Change 1 and still encodes the old diagonal boundaries; the AC and the spreadsheet now disagree, and the AC governs.

Several taxiway tables were deleted outright

Change 1 removed four dimensional tables tied to non-standard taxiway geometry, folding their guidance into the design-scenario text rather than fixed tables:

• Table 4-3 and Table 4-4 — dimensions for runway entrance/exit taxiways with two non-standard 90-degree turns (TDG 1A–2B and TDG 3–6 respectively) were deleted (items 21–22).
• Table 4-6 and Table 4-7 — crossover-taxiway tables with direction reversal, keyed to TDG and to ADG, were deleted (items 25–26).

Alongside the deletions, paragraph 4.8.5, High-Speed Exit Taxiways, was revised (item 23) and the two design scenarios for crossover taxiways in 4.8.6 were clarified (item 24). If your office carried those tables forward as canned values, they are no longer in the AC — the geometry now comes from the swept-path design methodology, not a lookup.

Appendix J fillets were updated

Taxiway fillet design saw a cluster of changes. Item 36 updated the tables in paragraph J.3 and clarified the notes; item 37 clarified J.4.2; item 38 added a new worked example (J.4.3, Critical Aircraft TOFA Calculation); items 39–40 revised Figures J-14, J-15, and J-30 and the J.5.15 mitigation guidance. The net effect is that the published Appendix J fillet tables (J-1 through J-8) and their notes are the Change 1 versions — the figures any current fillet design should be checked against.

Two new definitions

Item 1 added two definitions to the paragraph 1.5 glossary: touchdown zone (item 99) and V1 (item 100), the takeoff decision speed. These matter most where critical-aircraft and declared-distance discussions reference takeoff performance; having V1 formally defined in the AC removes an old ambiguity.

Other dimensional and clarification changes worth flagging

• ADG-VI widths revised. Item 34 revised runway, shoulder, and blast-pad widths for ADG-VI in Table G-12 and added footnote 14 (and appended footnote 12). If you work Group VI facilities, re-pull those widths.
• Precision OFZ adjusted. Item 13 adjusted the precision obstacle free zone on Figure 3-25.
• Declared-distance figures pruned. Item 35 deleted items 1, 3, and 4 from paragraph H.4.1 and removed Figures H-2 and H-3 in the declared-distances appendix.
• Circling-only approaches. Item 9 added a note to Table 3-2 clarifying guidance for circling-only approaches.
• Critical aircraft & non-standard conditions. Items 4–5 clarified paragraph 2.4 (non-standard conditions) and 2.6.1 (critical aircraft); item 6 expanded 2.7.2 on wrong-surface events.
• Service roads and EATs. Items 27–32 clarified end-around taxiways, apron taxilanes, and the several categories of service road in Chapter 6, expanding Table 6-1.

What it means for your workflow

If you take one thing from Change 1, take this: TDG is now a rectangular-range lookup, and the legacy FAA spreadsheet’s diagonal boundaries are obsolete. Re-key any internal TDG logic to Table 1-4. Then reconcile the deleted taxiway tables (4-3, 4-4, 4-6, 4-7) out of your templates, re-pull ADG-VI widths from Table G-12, and refresh fillet work against the updated Appendix J. AvPlot’s tools already implement the Change 1 logic — the TDG classifier uses the rectangular ranges, and the fillet tool follows the updated Appendix J tables — so they are a fast way to check your own figures against the current AC.

This article is a reference summary for planning use, not a substitute for the governing FAA text. Citations refer to AC 150/5300-13B (Airport Design) Change 1, dated August 16, 2024. Always verify dimensional values against the current AC before issuing a design product. See the full airport planning glossary or the AvPlot toolkit.