8-94-3 \--COCKPIT OBSERVER SEAT SAFETY BELT LOCKING PROCEDURES.

a\. The L-1011 cockpit observer seat safety belt system differs from
other aircraft in that the lapbelt portion has two spring-loaded reels
which keep the belt ends retracted until the crewmember pulls or extends
them for use. The lapbelt is not an adjustable length belt as is
commonly used on most other aircraft. Once the safety belt system is
fitted to the occupant, a locking lever located at the reel on each half
of the lapbelt must be manually actuated in order to keep the lapbelt
from extending further. If the locking lever on each half of the lapbelt
is not manually actuated (locked) the restraint system will not be
capable of performing its intended function. There is no inertia reel
locking device on the shoulder harness of the L-1011 system. The seats
have a five-point restraining system with nonretracting shoulder
harnesses and manual locks to keep the left and right sides of each half
of the lapbelt assembly from extended from their takeup reels.
Therefore, on L-1011 aircraft with observer seat lapbelt locks
installed, as well as on other aircraft equipped with a similar occupant
restraining system, it is necessary to adjust seatbelts and shoulder
harnesses tightly and to lock both sides of the lapbelts on cockpit
observer seats before takeoff, landing, and during turbulence.
Flightcrews of aircraft equipped with the kind of occupant restraint
system described in this ACOB should verbally inform occupants of
observer seats of the proper operation of their seatbelts and shoulder
harnesses and to visually confirm that the restraints are locked, if
locks are provided, prior to takeoffs and landings and turbulence
encounters during flight.

b\. Principal Inspectors who are assigned to air carriers that operate
the L-1011 aircraft and other aircraft equipped with a similar cockpit
observer seat occupant restraint system shall ensure that the following
actions are accomplished:

\(1\) Bring the contents of this ACOB to the attention of their
operator.

\(2\) Encourage their operator to instruct its flight crewmembers on the
steps to follow in hooking-up, adjusting, and locking the safety belt
and shoulder harness.

\(3\) Direct their operator to develop and use procedures to ensure that
cockpit observer seat occupants are given a proper briefing by a flight
crewmember to include the steps to follow in hooking-up, adjusting, and
locking the safety belt and shoulder harness. In addition, the
procedures must provide for a flight crewmember to visually confirm that
the safety belt locks and shoulder harness locks, if installed, are
locked prior to takeoffs and landings and when moderate to severe
turbulence is encountered during flight.

\(4\) Encourage the installation of a warning placard for seat occupants
stating the need to lock safety belts and shoulder harnesses, if locks
are installed.

c\. Each Flight Standards District Office (FSDO) manager will ensure
that sufficient copies of this ACOB are reproduced and given to each
inspector assigned responsibility for an operator or certificate holder
affected by this ACOB. The FSDO manager and supervisors are responsible
for assuring that the action required by this ACOB is completed by each
inspector assigned to their supervision within 120 days of receipt.

d\. Program Tracking and Reporting Subsystem (PTRS) Closeout. When the
action required by this ACOB is completed by the appropriate inspector,
a PTRS record will be completed using PTRS activity code \"1381\" in
section 1 of the PTRS data sheet and by adding \"ACOB89403\" to the
\"national use\" field. One PTRS record for each affected operator will
be completed and appropriate comments written in the \"comment text\"
section of the PTRS Data Sheet. The comments must include the method
used by the operator to comply with this ACOB.