Old Engineer, #1498
I think the action you describe above (energized coil drops out on low coil
voltage) to indicate the behavior of a "normally closed contact"
If you look at the schematic in the ntsb report, it's quite clear that the
contactor is drawn with normally closed contacts, which is the contactor state
with the coil / solenoid unenergised. While it may be latching to the open
state, there's no evidence for this and in fact, the contactor looks fairly
standard in that respect, but yes, it could be latching to the contacts open
state.
I originally brought this up in tech log, (#902), which might better explain why
this isn't a very good idea..