109 elevator trim

[WTE_Galway]

Originally Posted by irR4tiOn4L

Actually, no idea. Could you explain please? Does that mean the controls DON'T get heavy at speed?

No, it means you have a null elevator. Regardless of holding the stick or letting it go, the aircraft is longitudinally stable and will tend to return to the trimmed position.

Though it may seem counter-intuitive, this is not always the case for all aircraft or for all loads in a given aircraft. In fact a statically unstable aircraft may offer some advantages. Modern fighters with computer assisted controls are often not statically stable.

[irR4tiOn4L]

Originally Posted by WTE_Galway

No, it means you have a null elevator. Regardless of holding the stick or letting it go, the aircraft is longitudinally stable and will tend to return to the trimmed position.

Though it may seem counter-intuitive, this is not always the case for all aircraft or for all loads in a given aircraft. In fact a statically unstable aircraft may offer some advantages. Modern fighters with computer assisted controls are often not statically stable.

Thanks for the explanation, but isn't it the case that such statically unstable aircraft are not flyable without modern fly by wire systems? Ie, of course the 109 is going to be statically stable if it is a workable pre-fly-by-wire design? (perhaps not at all loads though)

I guess I fail to see how that is particularly relevant to this discussion or the heaviness of the trim controls when the tail is subject to faster moving air.

[Igo kyu]

Originally Posted by irR4tiOn4L

Thanks for the explanation, but isn't it the case that such statically unstable aircraft are not flyable without modern fly by wire systems?

I suspect the I-16 was statically unstable.