Trim tab and antiservo tab — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/trim-tab/  (sheet CC BY 4.0)
Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
Catalog version: 2026-10-20

Sizes: see table below
- A trim tab is a small surface on a control surface's trailing edge that moves opposite to the surface, holding it deflected so the pilot needn't; full nose-down trim moves the elevator tab full up (FAA PHAK ch.6).
- On a stabilator an antiservo tab moves the same way as the surface to add feel and prevent over-control (FAA).

parameter  value or range  source
Trim tab motion  opposite to the surface  FAA PHAK ch.6
Antiservo tab motion  same direction as stabilator  FAA PHAK ch.6

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- FAA: Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25), Ch. 6 Flight Controls — web — Publisher's page; dimensions are facts — https://www.faa.gov/sites/faa.gov/files/08_phak_ch6.pdf

No true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.
API: https://xemstudio.com/api/geometry?object=trim-tab