Do the airbrakes drop open once the hydraulic pressure bleeds off? Will there be circumstances where the front airbrakes will remain closed, while the one at the back will be open when the aircraft is parked on the ground?

Thank you for your feedback.

Перевод:
Воздушные тормоза открываются, когда гидравлическое давление сбрасывается? Будут ли обстоятельства, когда передние воздушные тормоза будут оставаться закрытыми, а задние - при открытии воздушного судна на земле?

Спасибо за ваш отзыв.

As I know, all three air brakes are opened together
The hydraulic system pressure drops when the airplane has staying on parking for a long time. And as a result, the air brakes partly drops. The rear (central) air brake has more weight and bottom location and it opens first and more.
And sometime а situation is possible when the rear air brake is open, but the front air brakes are closed

Look at this photos