













20150224 
17:55 



UNITS 
NOTES 






Distances 
1 Nautical mile 
1.8520 km 
Distances are expressed in nautical mile or kilometre, never in statue mile (1.609 km) 

Measures 
1 yard = 3 feet 
0.9144 metre 



1 foot = 12 inches 
0.3048 metre 



1 inch 
0.0254 metre 


Altitude 
10,000 feet 
3.0480 km 


Climb rate 
feet/minute 



Speed 
1 Knot 
1.8520 km/h 


Weight 
1 pound (lb) 
4.54 kilos 
With most NATO ordnance measured that way, weights are usually expressed in pounds 

1 grain (gr) 
0.064799 g 
or 1/700 lb  however the grain unit (for bullets) is NEVER used on AAC  "gr" may be used here and there on these pages but it should always be read as grammes; this erroneous use of the "gr" abbreviation is being corrected. Don't hesitate to ask if in doubt 

Volume 
1 gallon 
4.54 litres 
When volumes are expressed in gallons, it is always in "imperial gallons", thus 4.54 litres 




Other : 
1 gallon (US) 
3.7854 litres 
or 
0.8338 gal 


Mass 
Fuel : 0.76 kilos/litres or 
7.6lb/gal 
Real 
Avgas : 
0.721 
kg/l 
JP4/JP5 
0.815 
kg/l  
1.588 
lb/l 
1.795 
lb/l  
7.210 
lb/gal 
8.150 
lb/gal  
6.012 
lb/gal  (US) 
6.795 
lb/gal  (US)  
The AAC standard density for fuel, either AvGas or JetFuel is thus 0.76kg/litre or 7.6lb/gal, but real data is shown here for reference 

Power 
Piston engines 
Power is usually expressed in hp rather than in kw. The conversion values are : 

1 kw = 
1.3410 hp 
1 hp = 
0.7457 kw  
Power 
Jet engines 
Power is usually expressed in lbf. The conversion values are : 

1 lbf 
0.0044482216 kN 
1 kN = 
224.808943 lbf  
SFC 
Specific fuel consumption 
usually expressed in mass of fuel per hour,
related to the power output, either in "hp" 

if related to fuel volume (always in imperial
gallons : 1 gal = 4.54 litres), then the conversion is 

7.6 lb 
= 1.000000 gal 

1.0 lb 
= 0.131579 gal 
1.000 lb/hp/hr 
= 
0.132 gal/hp/hr 
