Airplane reaction with extended flaps

[Vita_CZ]

Greetings to developers!

I like the L-39 very much, the only thing which distracts me is that strange cockpit and FF shake when I extend the flaps.

I see no reason why airplane should shake with flaps extended and speeds between 250 and 220 kph. In fact, with flaps extended, the actual AOA should be lower than when in clean configuration.

 

Vita

[Flamin_Squirrel]

Greetings to developers!

I like the L-39 very much, the only thing which distracts me is that strange cockpit and FF shake when I extend the flaps.

I see no reason why airplane should shake with flaps extended and speeds between 250 and 220 kph. In fact, with flaps extended, the actual AOA should be lower than when in clean configuration.

 

Vita

 

Not sure about the shaking but, while AoA will be less for a given airspeed with flaps, stall AoA will actually be less also.

 

In other words, you can't fly at as high an AoA with flaps down, but the extra lift they generate still allows you to fly slower (with the added bonus that lower AoA means better visibility).

 

[Vita_CZ]

I discussed this shaking with our airforce pilot who used to fly L-39 a lot and he said there is no shaking or reason for shaking when flaps are extended at proper speed. The machine just changes pitch angle (as it currently does), needs to be re-trimmed and continues smooth flying.

Edited October 14, 2015 by Vita_CZ

[jonboede]

Agreed. No shaking at all when flaps are extended. There is a minor pitch change.

 

And it only needs to be re-trimmed because you're slowing down, not because of the flaps.

[Vita_CZ]

Thank you for fixing this! No shaking with latest patch!

Vita