The UK system is simple. Driving distances are always measured in miles and yards.
Flying in the UK is rather different. Distances are measured in nautical miles, and airspeeds in knots. Heights when flying at low levels are measured in feet, and at higher levels in flight levels (units of 100 feet).
Heights are measured in feet above the local ground, but altitudes are measured in feet above MSL (Mean Sea Level). Knowing the difference can be a matter of life and death. If you are coming in to land and your altitude is 500 ft that would be bad news at Biggin Hill, because the runway is 600 feet above sea level.
Oh, and visibility is measured in kilometres, and cloud cover in oktas (units of 1/8 of the sky). Simples!
The UK system is simple. Driving distances are always measured in miles and yards.
Flying in the UK is rather different. Distances are measured in nautical miles, and airspeeds in knots. Heights when flying at low levels are measured in feet, and at higher levels in flight levels (units of 100 feet).
Heights are measured in feet above the local ground, but altitudes are measured in feet above MSL (Mean Sea Level). Knowing the difference can be a matter of life and death. If you are coming in to land and your altitude is 500 ft that would be bad news at Biggin Hill, because the runway is 600 feet above sea level.
Oh, and visibility is measured in kilometres, and cloud cover in oktas (units of 1/8 of the sky). Simples!