Fundamental Constants and Units

Roussak and H.D. Gesser, Applied Chemistry A Textbook for Engineers and Technologists, DOI 10.1007/978-1-4614-4262-2, Springer Science-f-Business Media New York 2013 

On July 23, 1983 a new Boeing 767 (Air Canada Flight No. 143) refueled in Montreal. The fuel gauge was not working so it was decided to refuel by the manual use of a dipstick which correctly showed the fuel in the aircraft to be 7,682 L. The required fuel for the trip was 22,300 kg. The mechanics, using 1.77 as the density conversion factor, calculated the required fuel necessary, 

They believed 1.77 represented the conversion of liters to kilograms, in fact it was the conversion of liters to pounds, i.e., 1.77 Ib/L is the density of the jet fuel. The density of the jet fuel in proper units is 0.803 kg/L and the amount of fuel which ought to have been added was 20,163 L. Using 1.77 without any units led to a near disaster. 

Holler W, Mona M (1989) Freefall a true story. St. Martin s Paperback, New York 

International System of Units, Constants, Units, Uncertainty http //www.physics.nist.gov/ 

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