BOAC
- I am totally confused by what we know so far of the tail 'feathering' system, but I think we must assume the tail
movement is 'powered' somehow, and I can see significant aerodynamic forces moving the tail to 'feather', but I
cannot see how the reverse will happen - unless the 're-entry' is inverted.
I too am confused, but some items in the patent seem to clarify some points and raise others.
From para [0018] Pilot-controlled pressurization of actuators 33 drive the aft wing sections and tail booms upwardly and downwardly.
From para [0019] When the wing sections are retracted after reentry, actuators 41 are again pressurized to extend pistons 43 to reengage the locking system.
So it seems that:
- Intentional feathering and un-feathering is by pneumatic upward and downward actuation.
- The feathering lock is re-applied as soon as the downward actuation is completed.
Leaving the following questions open:
- What keeps the booms in the feathered position, as there is no locking mechanism for this.
--- Pneumatic pressure?
--- Aerodynamic forces?
- What keeps the booms in the unfeathered position after unlocking, but prior to feathering?
--- Aerodynamic forces? But only in appropriate flight regimes?
--- Pneumatic pressure? But have the downward actuators been pressurized yet?