Epsomdog,
Thanks, good information from the CMM.
Derfred,
Not surprised.
Well, just to stir things up, after reading this thread I went down the back of one of QF's newest B737-800s to check it out and guess what:
Every seat has the buckle on the left.
I believe the seat assembly CMM specifies the tip/buckle placement for safety reasons.
Buckles hanging in the aisles or out an exit window could impede the evacuation during an emergency.
Finally found a U.S. regulation and other authorities use similar or same language. CFR § 121.311 Seats, safety belts, and shoulder harnesses:
(i) At each unoccupied seat, the safety belt and shoulder harness, if installed, must be secured so as not to interfere with crewmembers in the performance of their duties or with the rapid egress of occupants in an emergency.
From a B737 AMM used during a "C" check a couple of years ago:
2. Detailed Inspection of the Passenger Seat Belts
NOTE: This is a MSG-3 scheduled maintenance task.
C. Detailed Inspection of the Passenger Seat Belts
SUBTASK 25-22-00-210-001
(1) Do this check of the passenger seat belts:
(a) Do a detailed visual inspection to make sure the seat belts are not worn, frayed, or damaged.
(b) Pull on the seat belts to make sure they are attached tightly to the seat.
(c) Do these steps to make sure the seat belt operates correctly :
1) Put the tongue end of the belt in the buckle.
NOTE: You can hear a click when the tongue is engaged in the buckle.
2) Lift the release handle on the buckle to disengage the belt halves.
As you can see there is no reference to the tip/buckle in the above AMM reference. Maintenance check instructions are routinely written using the AMM reference and many technicians/engineers would never see the CMM unless overhauling the seats.
AMMs and check cards should be checked and revised if needed to include correct information.