Page 004
25-20-00
MB680
Martin-Baker
MISSION SEAT ETSO
MAINTENANCE MANUAL
3. Function
A. 5-point harness
The QRB provides quick connection and disconnection of the four lugs of the 5-point harness (the LH lap
strap is permanently connected to the QRB). The lap straps adjust the 5-point harness for correct fit.
B. Height adjustment
When the raise/lower lever is pulled, the vertical adjustment cable withdraws the vertical lock plungers
from the bucket assembly. This lets the bucket assembly move vertically on the tracks of the lower frame.
The bucket assembly is pushed DOWN by the weight of the occupant, and pushed UP by the pressure of
two vertical gas struts. When the correct height is reached, and the raise/lower lever is released, the
vertical lock plungers lock the bucket assembly to the lower frame.
C. Recline adjustment
When the recline lever is pulled, the recline plungers are disengaged from the racks and the recline gas
struts support the backrest assembly. If the backrest assembly is now pushed firmly it compresses the gas
struts and the backrest assembly moves to a new position. At the new position the recline lever is released
and the recline plungers engage the rack.
D. Fore and aft adjustment
When the fore/aft lever is pulled, the two floor locking plungers are disengaged from the aircraft track and
the seat can be moved forwards or backwards. When the desired position is achieved, the fore/aft lever is
released and the floor locking plungers engage the aircraft track.
E. Harness lock/unlock
When the harness lock/unlock lever is in the down (LOCK) position the 5-point harness locking reels are
locked. When the harness lock/unlock lever is in the up (UNLOCK) position the reels are unlocked. In the
LOCK position, the shoulder straps prevent all forward movement. In the UNLOCK position the shoulder
straps can be extended, but will lock with rapid movement.
F. Seat rotation
When the rotation lever is pushed rearwards, the spring-loaded floor locking plunger is disengaged from
the carriage floor and the seat can be turned. As the seat is turned the four top floor-fittings are disengaged
from the four feet. The spring-loaded locking plunger engages the lower frame every 15 degrees to hold
the seat at a new position. The four feet engage the top floor-fittings at 90 degrees, 180 degrees, 270
degrees and 360 degrees.
G. Headrest adjustment
The headrest can be pushed into or pulled out of the backrest assembly to adjust its height. To set a
different angle, the headrest must be pushed to the side to disengage an internal mechanism, then set to
the new angle. When the new angle is set, the headrest is released and an internal spring pushes it back
to the locked position.
H. Armrest adjustment
The armrest is adjusted by turning the adjustment rod at the front of the armrest.
To Next Page
Loading...