FMC Route Dump At End Of Flight?

[NSEU]

I understand there are variations when it comes to what happens to FMC Route data at the end of a flight.

I've been told by a pilot that a 737 will dump Route info at 20kts during rollout (Smiths FMC)... I've also been told that a 744 FMC (Honeywell) holds Route 1 missed approach data and all of Route 2.

As a maintenance engineer on 744's and 767's, I do recall seeing some Route data remaining on the ND's/EHSI's after a flight, but, at the time, wasn't able to determine what Route (1 or 2) the pilots had actually used during approach/landing.

Does anyone have any other opinions/data on this. In particular, I'd like to know what happens on a 767 Honeywell box. If the data is dumped, is it based on air/ground, flaps, groundspeed or something else... or a combination of these.

BTW, I understand the initialization data is dumped from a Honeywell box when the fuel cutoff levers are set to cutoff.

Thanks in advance.
Regards.
NSEU