MCMXCIVRS
More toys than space
This is what can happen with metric, and this was Air Canada!
https://en.wikipedia.org/wiki/Gimli_Glider
Without having multiple standards of measure to deal with there is little chance of a conversion error.
The other somewhat ironic error that happened in that event was that the pilot chose to use the slightly longer decommissioned runway/drag strip instead of the parallel active one which was actually used for gliding operations by the Air Cadets.