Question 1

How do I install AeroSheet?

Accepted Answer

Open Google Sheets, go to Extensions → Add-ons → Get add-ons, and search "AeroSheet". Click Install. The sidebar appears under Extensions → AeroSheet → Open. No account required, no file uploads, no new app to learn.

Question 2

Does AeroSheet work in Excel or LibreOffice?

Accepted Answer

No. AeroSheet is a native Google Workspace add-on and runs exclusively inside Google Sheets. The physics engine is bundled directly into the Sheets sidebar to enable real-time 3D rendering and instant cell formula execution.

Question 3

Do I need a degree in aerodynamics to use it?

Accepted Answer

The Free tier is designed to be accessible—if you know your wingspan, chord, and speed, you can generate a drag polar in two clicks. The Pro tier exposes the full UIUC database and CAD exports, which assumes basic familiarity with airfoil nomenclature and fabrication workflows.

Question 4

The sidebar is blank or stuck loading. What do I do?

Accepted Answer

Close the sidebar and reopen it via Extensions → AeroSheet → Open Designer. If that fails, try a hard refresh (Ctrl+Shift+R). Google Workspace sidebars occasionally time out on first load—this is a known Google platform quirk. If it persists, ensure you aren't logged into multiple Google accounts in the same browser window.

Question 5

How do I activate my Pro license?

Accepted Answer

After purchasing on Gumroad, you'll receive a license key via email. Open AeroSheet → click the Star icon in the bottom right of the sidebar → paste your key. The key is securely stored per Google account, so you only enter it once.

Question 6

Can I use my license on multiple Google accounts?

Accepted Answer

One license covers one Google account. If you need team coverage (e.g., a university lab, AIAA DBF team, or UAV startup), email us for a multi-seat arrangement.

Question 7

What's actually Free vs. Pro?

Accepted Answer

Free gives you the full physics engine (Prandtl LLT, polar sweep, stall detection), the NACA 4-digit generator, 3D wing viewer, and core =AERO_* cell formulas (Lift, Drag, Cl, Status). Pro unlocks the full UIUC database (1,661 airfoils), CAD exports (STL, DXF, CSV, DAT), batch speed/AoA sweeps, multi-profile trade studies, and advanced formulas (=AERO_CD, =AERO_LD, =AERO_STALL).

Question 8

Is this a subscription?

Accepted Answer

No. $49 once, own it forever. All v1 updates are included. We hate subscriptions for utility tools as much as you do.

Question 9

How do the =AERO_* formulas work?

Accepted Answer

AeroSheet registers custom Google Sheets functions that call the bundled physics engine offline. They compute values instantly just like =SUM() or =VLOOKUP()—but the math is Prandtl lifting-line theory.

Example:
=AERO_LIFT("4412", 5, 15, 1.2, 0.2)
// airfoil, AoA°, speed m/s, span m, chord m
// → Lift force (N) at given conditions

Question 10

Why does my formula show #ERROR or #PRO?

Accepted Answer

Most common causes: (1) The add-on isn't fully initialized—open the sidebar once to trigger the engine. (2) The airfoil code is passed as a number instead of a string (use "2412" not 2412). (3) You're trying to use a Pro formula (like =AERO_LD) or a UIUC airfoil without an active license.

Question 11

Does using the UIUC database in formulas require internet?

Accepted Answer

No. To bypass Google's strict execution time limits, AeroSheet securely caches the geometric constants (camber and thickness) of your selected airfoils directly into the sheet's memory. Your formulas evaluate instantly across hundreds of rows without hitting network quotas.

Question 12

What physics model does AeroSheet use?

Accepted Answer

AeroSheet uses both linear Prandtl Lifting-Line Theory (PLLT) and Nonlinear Lifting-Line Theory (NL-LLT) via the Gallay & Laurendeau iterative scheme. It evaluates 16 spanwise stations using Gaussian elimination. The core solver is a strict TypeScript port of a Fortran original (Kostić, MF Belgrade 2008).

Question 13

How accurate is it compared to XFOIL or CFD?

Accepted Answer

AeroSheet is a Phase 1 Conceptual Sizing Tool. For wing sizing, aspect ratio trades, and general polar curves, it gets you 95% of the answer in 0.05 seconds instead of 4 hours. For detailed viscous drag validation or separation boundary prediction, use XFOIL. We don't claim to replace CFD.

Question 14

Why does the stall angle change with airspeed?

Accepted Answer

AeroSheet applies an empirical Reynolds number correction to the geometric stall angle. Below Re ~500k, boundary layer transition effects cause earlier stall (laminar separation bubbles). Changing altitude or airspeed dynamically recalculates Re, which updates the stall margin realistically.

Question 15

What CAD formats does AeroSheet export?

Accepted Answer

STL (3D printable, Cura/PrusaSlicer ready), DXF (AutoCAD/Fusion 360 splines), CSV (raw XYZ coordinates), and DAT (XFOIL-compatible).

Question 16

My STL imports sideways in the slicer. How do I fix it?

Accepted Answer

AeroSheet intentionally pre-rotates the STL so the wing chord aligns with X, and thickness aligns with Z (standard slicer "up" axis). If your slicer still imports it sideways, simply rotate it 90° on the X-axis in your slicing software.

Question 17

Can I bake the incidence angle into the DXF export?

Accepted Answer

Yes. In the CAD drawer, adjusting the "Mounting Incidence" angle will mathematically rotate the exported 2D DXF ribs. This allows you to laser-cut ribs that naturally glue flat to your building board at the correct aerodynamic angle of attack.

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