HENSYNTH static margin stability screening

Static margin on the requirements run

After Run screening, the Requirements run report may show Static margin with unit MAC — a fraction of mean aerodynamic chord, not a distance in metres. The ? help modal defines purpose: how far the neutral point sits behind the centre of gravity. Positive margin means the wing–tail combination is statically stable in pitch in this screening model; negative margin means the nose would diverge in the same model.

Formula path the UI documents

HENSYNTH exposes the relationship in the help dialog so design reviews stay traceable:

• Static margin equals neutral point minus centre of gravity, divided by MAC.
• Neutral point uses aerodynamic centre plus a tail-volume term with horizontal tail volume and MAC.
• Tail volume combines tail area, tail arm, wing area, and MAC in the standard bookkeeping form written in the modal.

Those inputs come from the aircraft you saved: wing area and span, horizontal tail span and arm, fuselage length scale. Editing tail arm on the Aircraft page without re-running leaves stale stability numbers on the report.

Geometry levers without guessing numbers

When stability-related compliance fails or margin is uncomfortably low in screening, engineers typically lengthen tail arm, increase horizontal tail span, or adjust CG proxy through weight build-up — always re-run to read updated predictions. HENSYNTH does not auto-redesign the tail for you on the Stability sidebar pages in the same pass as requirements; the requirements run static margin tile is the quick pitch-stability screen tied to mission review.

Relationship to deeper stability pages

The project sidebar includes stability and related analysis routes for specialists extending beyond the requirements snapshot. The static margin tile is the headline pitch metric on the requirements run for PASS/FAIL against any stability requirement row the engine emits. Use the dedicated stability views when the project phase needs more than one MAC fraction on a slide.

Not flight-test stability

Static margin here is a conceptual criterion from textbook tail-volume and CG placement. It is not dynamic stability analysis, not control-law verification, and not substantiation for certification. Tunnel or flight-derived neutral points are outside what this screening row claims.

In simple words: what this page is for

Static margin on the requirements run is a pitch stability screen in MAC fractions — neutral point, CG, tail volume — from the ? help modal, not flight-test stability approval.

This lesson exists because aircraft teams often jump to heavy CFD before the mission is even closed. HENSYNTH static margin stability screening keeps the focus on conceptual screening you can explain in review.

Why the topic matters

Engineers lose time when a title sounds clear but the page only sketches the idea. This article expands HENSYNTH static margin stability screening so you can answer three questions without jargon: what is the idea, when do you use it, and how do you check it in a HENDOI product.

Read the sections above for the core definitions. Use the steps below to move from reading into a real project trail you can share with a teammate.

How to apply this in HENDOI

In practice: open HENSYNTH after you sign in, set or confirm geometry, write mission targets on Requirements, Run screening, then read PASS / FAIL with margins. Use Mission, Performance, Trades, Optimize and Reports only after the screening snapshot exists. Numbers come from stored runs — the product does not invent missing values.

If you still need the wing section itself, finish that work in HENFOIL first, then continue the aircraft in HENSYNTH. One HENDOI account covers both. Plans stay Student USD 9, Professional USD 29 and Team USD 89.

What this page will not claim: HENSYNTH is conceptual and preliminary screening. It is not wind-tunnel data, not certification CFD, and not a compliance certificate for an authority. PASS / FAIL means requirement-versus-prediction inside the product.

Checklist before you leave this page

• Can you state the idea of HENSYNTH static margin stability screening in one sentence?
• Do you know which product owns the next action — HENSYNTH or HENFOIL?
• Will every number you keep carry a method label or a stored-run source?
• If you are new here, have you opened Register or Login?

Related reading on this site

• HENSYNTH candidate cards, Use this aircraft, and CAD
• HENSYNTH compliance matrix: PASS, FAIL, and margin
• HENSYNTH download and share technical reports
• HENSYNTH Geometry page: wing, fuselage, and tails
• All HENDOI blog articles
• HENSYNTH product page
• HENFOIL product page
• Pricing — Student, Professional & Team
• FAQ
• Login · Register now