Originally Posted by AIR FRANCE 340

You are right, the CV 990 did not have ailerons on the outer wings.
It only had "high speed" ailerons.

I explain and make a comparison with the B 747.
On a B 747-400, you have inner ailerons and outer ailerons.
The outer ailerons are activated when the speed of the aircraft is below 232 kts and when the flaps are extended.
Above 238 kts, and when the flaps are in, these ailerons are blocked and only the inner ailerons (and some spoilers) are used.

Why this ?
To prevent an excessive roll rate at high speed and provide a good handling in roll at low speed.

The CV 990 had only "high speed" (inner) ailerons between the inner flaps and the outer flaps (between the two carrots).

I don't want to offend anyone, but unfortunately, too much of a rush about this model, some guesswork, no attention to the documents which were brought to the forum and we were told "everything will be corrected" ...

Jean Pierre.