Aerodrome Reference Code calculator

Enter the aeroplane reference field length and wingspan. The code drives the strip, the RESA and the taxiway separations — but not, as many assume, the runway width.

What the reference code is for

The reference code exists so infrastructure is dimensioned from the aeroplanes an aerodrome intends to serve, not the ones it happens to have seen. Two elements. The code number, 1 to 4, from the aeroplane reference field length — a normalised figure from the flight manual, not the length of your runway. The code letter, A to F, from wingspan.

They are taken independently. On a mixed fleet the number may come from one aeroplane and the letter from another, and nothing is wrong with that.

What the code does not drive

This is where people go astray. Runway width and taxiway width are not keyed to the code letter at all. They are keyed to outer main gear wheel span, a different measurement that cannot be derived from wingspan. Two Code C aeroplanes can carry very different wheel spans and produce different width outcomes.

The confusion is not the reader's fault. A footnote elsewhere in Annex 14 describes wheel span as element 2 of the reference code, which is loose drafting carried unedited into the current edition and into both national transpositions checked here. Element 2 is the wingspan-derived code letter. Wheel span is separate.

Boundaries

Every band reads up to but not including its upper figure, so a 24.0 m wingspan is Code C, not Code B. Above 80 m there is no code letter — the table stops, and the guidance points to Doc 9157 rather than an invented Code G.

Every figure on this page is cited to the paragraph it comes from. Where a value is a Recommendation rather than a Standard, the row says so. Verified against ICAO Annex 14 Volume I, with EASA CS-ADR-DSN and two national transpositions used as cross-checks.