The American system of measurement and its unitsfeet, miles, pounds, and gallonsare quite bizarre.
But the legislation was not strong enough and many industries chose not to convert.
Otherwise the results could be disastrous, just like Air Canada found out in 1983.
Air Canada Boeing 767 C-GAUN, the Gimli Glider, taxing at San Francisco International in February 1985.
The next morning, Captain John Weir and co-pilot Captain Donald Johnson were told about the problem.
The plane flew to Toronto and then to Montreal without incident.
At Montreal, the airplane was taken over by Captain Bob Pearson and First Officer Maurice Quintal.
As they waited for a dripstick test, a ground engineer climbed into the cockpit to inspect the FQIS.
Immediately, the fuel gauges went offline.
The technician left the craft forgetting to return the circuit breakers to their original positions.
Graduations on the tube indicate the depth of the fuel in the tank in centimeters.
But the technicians didnt know that.
The correct conversion factor should have 0.803 kg/liter, which would have yielded a figure of 20,088 liters.
The plane reached Ottawa without incident.
At first the pilots assumed an instrumentation error and turned off the alarms.
But minutes later, both the engines flamed out.
The 767 was one of the first jets to use an electronic instrument system powered by its engines.
This meant that when the engines stopped working, all the instruments went dark.
Pearson and Quintal decided to divert the plane to Winnipeg, 65 miles away.
But after making some calculation, Quintal announced that they would never make to Winnipeg.
It included a road race course, a go-kart track, and a dragstrip.
As fate would have it, it was race day and the track was full of cars and campers.
As the plane approached the runway, the pilots realized they were coming in too high and fast.
If they didnt loose altitude fast, they would overshoot the runway entirely.
Pearson, an experienced glider pilot, decided to execute a forward slip to increase drag and reduce altitude.
With both of its engines dead, the plane made hardly any noise as it approached the drag strip.
Pearson could only hope people got out of the way.
The friction helped slow the plane down and kept it from crashing into the crowds surrounding the runway.
All 61 people on board survived.
These suspensions were overturned following an appeal.
Two years later, Pearson and Quintal were awarded the first ever Federation Aeronautique Internationale Diploma for Outstanding Airmanship.
The Gimli Glider was scrapped in 2014.
