The scienceof airsidemotion.
Aircraft don’t move like lines on a drawing. Plan for the space they actually need.
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A320 / cockpit tracking / 90° turn
The cockpit follows the line. The wheels cut the corner.
That difference changes the pavement you need. In this 45 m turn, the A320’s outer tyre comes within 0.20 m of the edge—short of the 3.00 m criterion in this study.
Inspect the calculationMeasured minimum: 0.20 m. Required margin: 3.00 m.
Engine-computed example. A planning aid, not an operational clearance.
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From swept paths to stand design.Compare supported analyses and their standard basis
| Capability | Standard basis | QGIS | Cloud | AutoCAD | Revit |
|---|---|---|---|---|---|
| Aircraft path and group path nose-gear, cockpit or custom tracking | ICAO Doc 9157 Pt 2 App. 1 | ● | ● | ● | ● |
| Pushback and towing towbar and towbarless tugs | Nose-wheel tow limit | ● | ● | ● | ● |
| Turning radii R1–R6 and 180° turn | Manufacturer APM method | ● | ● | ● | ● |
| Jet blast contours and intake hazard | ICAO Doc 9157 Table A2-1 | ● | ● | ● | ● |
| GSE and trailer trains | Steering lock, jack-knife > 90° | ● | ● | ● | ● |
| Wingtip and edge clearances | Annex 14 Table 3-1 · AC 150/5300-13B | ● | ● | ● | ● |
| Stand design and conflicts | Annex 14 §3.13.6 | ● | ○ | ○ | ○ |
| Taxiway fillet / required pavement | Doc 9157 Table 1-1 · FAA TESM | ● | ○ | ○ | ○ |
| Envelope separation check | User-defined separation | ● | — | — | — |
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A reviewer should be able to follow your reasoning. Tractrix publishes the geometry, the aircraft data and the model’s limits, so an analysis can be checked and reproduced.
388 aircraft types. From the FAA Aircraft Characteristics Database, with manufacturer steering limits cited for 44 types. Plus 14 ground-vehicle configurations.
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