The load adjuster for aircraft is used to spot the payloads on military aircraft to maximize use of the capacity of the airframe. Most commercial aircraft do not have to deal with near maximum loads in a lot of different configurations, and usually follow different rules. At most moving passengers seating or restricting loading of baggage to certain areas will balance an aircraft.
Other controls with commercial aircraft involve managing which fuel to consume as well.
But with military and other aircraft large loads near capacity may occur which are different for each mission.
This device allows the loadmaster or pilot to verify that loads are proper for safe military operation. Military operations allow for operation beyond ordinary limits when necessary, so load balancers and other training inform the crew what they can do without converting a mission into a one way one.
This is the first one I've gotten I could trace to a specific aircraft (or I suspect I have). Rather than the contract number being the number that traced this aircraft, the c/n number appears to be more accurate.
I think this entry is the aircraft which would have received this unit.
138467 (c/n 58-146) to Vietnam
The unit is as near new as I've ever gotten. It also includes the instruction manual, as well as the mounting clip to hold it on the aircraft.
I am wondering if "to Vietnam" means these had ownership transferred to the Vietnamese Navy.