If you come from the UK or the USA, you may be surprised to
discover that in mainland Europe, we don't use the same units
as you do.
(Our units are closer to the international system used world
wide in physics! Russians are even better, since they mesure ACFT
altitudes and heights using meters instead of feet. Why the hell
should we use so exotic units as feet, gallons, inches, statute
miles, pounds... just because we fly? Just ask a physician what
he thinks about them ;o) )
For gas, we use liters instead of gallons. 4.54 liters =
1 UK gallon. 3.78 liters = 1 US gallon
For ground elevations, we use meters instead of feet. 1 meter
= 3.33 ft. (3m=10ft)
For weights, kilograms instead of pounds : 1 lb = 0,453 kg
For atmospheric pressure, millibars instead of mmHg. Standard
atmosphere has a pressure of 1013 mbars. (You may sometimes see
hecto Pascals, or hPa. It is the same thing as a millibar)
For distances, we usually use kilometers, but in aviation,
we use miles instead. These are nautical miles. There is no statute
mile in mainland Europe. That's why noone will ever precise this.
In France magnetic declination is between 0 (in the South
East) and 5 (in Brittany) degrees West.
Hour, in France, is UTC+1 in winter, and UTC+2 when daylight
saving time is used. (From the last sunday of march to the last
sunday of october).
You can use euroVFR in order to compute aeronautical units conversions.
For other units, you may have a look on this page, from a English aviation magazine's
web site. (Pilot)