Conceptual aircraft design
Set the mission, size the wing, build up the drag, pick the engine and prop, then balance it and check the loads. Every number is explained, labeled for how far to trust it, and checked against airplanes that already fly.
How it works
One coupled model sits under every step. Change one thing and weight, speed, stall, climb and balance all respond. Then see exactly why.
Show the math
The equation, every symbol defined, your values substituted, its source, and what it feeds next.
W₀gross weightWe/W₀empty-weight fraction, from the trend for your materialWf/W₀fuel fraction, from the mission's segmentsConfidence
Every number carries one of five labels.
Try it here
Stall, takeoff, climb and cruise each draw a line. Find the corner that meets them all.
An illustration with textbook formulas. With the point focused, the arrow keys move it.
Honest failure
Designs can fail to close, stall too fast or fall outside CG limits. The app says why, and which levers help.
Offline
Install it on iPad or Mac and it runs in the flight bag.
Experiments
Try-this experiments show the before and after of each headline number, with one-tap undo and a pinned baseline to compare against.
Example changes, to show the format.
Validate
Four real airplanes run through the same model you design with. Its error is the first thing it shows you, and a change that makes it worse can't ship.
| Airplane | Empty weight | Cruise | Stall | Climb | Takeoff roll |
|---|---|---|---|---|---|
| Van's RV-7A | −1.2% published 1,114 lb | −6.1% published 171 kt | −3.1% published 50 kt | −6.0% published 1,850 fpm | −28.1% published 500 ft |
| Lancair 360 | −3.0% published 1,090 lb | −2.7% published 205 kt | −5.6% published 59 kt | +12.6% published 1,750 fpm | +39.1% published 390 ft |
| Glasair III | +2.9% published 1,625 lb | −10.3% published 242 kt | −1.5% published 64 kt | +6.7% published 2,140 fpm | −9.3% published 700 ft |
| Cirrus SR22 | −0.9% published 2,350 lb | +2.5% published 183 kt | −4.3% published 60 kt | +25.2% published 1,270 fpm | Not published |
The design loop
Payload, range, speed, stall, climb and takeoff.
Material, empty-weight judgment and reserves.
The wing loading and power loading that meet every requirement.
The wing section, its Reynolds number and roughness.
Aspect ratio, taper, washout and flaps.
Seating, fuselage, gear, cooling and finish.
Cabin, nose and canopy shape.
Piston, diesel, turboprop, electric or hybrid.
Powerplant, cruise power and altitude.
Diameter, blades, pitch control and RPM.
Tail volumes, tail arm and CG limits.
Where the wing, battery and baggage sit.
Category and design speeds, on the V-n diagram.
What to change next, from the report card.
How far to trust the model, on real airplanes.
Configuration, the laminar flow study, takeoff and landing, control and handling, wing structure, cost and flight test planning.
Built on the books
Each lesson cites the chapter it draws on, so you can go deeper in the book.
Who it's for
See why your airplane stalls, climbs and cruises the way it does, in the numbers you already fly by.
Work through the tradeoffs behind a homebuilt before you choose a kit or start a clean sheet.
Do the conceptual design loop from your course with the equations live and every result traceable.
What's next
No dates. Items move as the work moves.
Sign in with an email link, Google or Apple, and pick up on the Mac where you left off on the iPad.
Pick an aircraft class, a challenge and a level. Trainer, light sport, fast homebuilt and 4-seat touring open first.
Design to a real airplane's mission without its name, then see how close you got, side by side.
Export your airplane and fly what you just designed.
Get started
Open the first steps in your browser, no account needed. Sign up in the app after your third step, and get a founding-member discount when Pro launches.
For learning only. The workbench teaches conceptual aircraft design. Its numbers are educational estimates from simplified methods, not engineering data. Don't use them to build, modify or fly an aircraft.
Reference airplanes are named to compare published figures. Books are cited for reference; the Workbench isn't affiliated with their authors or publishers. About the Workbench