6

The trim tab is like a control surface for the control surface. By changing camber at the rear end of the control surface, it creates a local force which changes the balance of forces such that the force-free deflection angle (sometimes called auswehwinkel after the German word for this angle) is shifted in a direction opposite to the deflection of the tab. ...


6

Is the aircraft also equipped with trim tabs? From the images available online (this is a youtube screenshot, click it to see the larger version), no. And see point 3 on why I was not expecting any different. If an aircraft has both trim tabs and movable stabilizer I do not see the need of such a solution, a trimmable stabilizer is already ...


5

The trim system on an aircraft relieves the control pressures so that the aircraft maintains an attitude without pressure on the control system. When hand-flying this is very noticeable in that you constantly have to be pushing, pulling, or turning (in the event you have aileron trim) to maintain an attitude. Notice how I don't say "straight and level", you ...


4

Trimmable horizontal stabilizer (THS) and trim tab serve the similar purpose for two entirely different control architectures: Trim tab neutralizes the force on the pitch control for a reversible control system. THS neutralizes the pitch position (and, in the process, the force) for an irreversible control system (e.g. hydraulically/electromechanically ...


4

Trim is simply a force that offsets the neutral position of the control surface. On aircraft with mechanical controls it is provided aerodynamically via trim tab, but it can also be provided by springs, hydraulics, or simply by adding the selected offset in the fly-by-wire computer. Since F-16, F-18 and F-22 are all fly-by-wire, the last option is most ...


3

Pitch trim on an aircraft with a stabilator is normally accomplished by moving the entire stabilator and holding it in its new trimmed position either mechanically (using the same mechanism as normal pitch control), aerodynamically (using an "anti-servo tab"), or some combination of the two. The concept is similar to stabilizer trim as discussed in the ...


3

I've been around light airplanes for about 45 years and I've never seen a trimable stab and trimable elevator using a tab together. The closest I can come to that is the elevator trim bungee that is included with the jackscrew stab trim on the Piper Super Cub. The Super Cub has a moveable stabilizer that is the primary trim device, but also has a spring ...


1

It's unlikely that any airplane with a THS also has trim tabs. The benefit of adding them is slight (partial protection against failure of hydraulics), while the cost is extra mechanical complexity and extra drag. The extra drag is particularly important for airliners.


1

The trim tab is sized first, and then the tab hinge moment is computed. The trim tab is sized to the conditions required for maximum trimmed position of the aircraft at: low speeds; all relevant CG positions; all relevant flap settings; The contribution of the trim tab to the elevator hinge moment is tiny, see the right hand graph which is measured data ...


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