00:INDEX
30:Bases
40:Maps
50:R.O.E.
60:Crews
70:More
80:Story
11:Weapons
13:Targets

2015-02-24

17:55

 

MEASUREMENTS  and  STANDARDS

See also : The Mach Number

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"
  (engine horsepower of piston or turboprop engines) or in "lbf" (thrust of jet engines)

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

7.6 lb

= 1.000000 gal

1.0 lb

= 0.131579 gal

1.000 lb/hp/hr

=

0.132 gal/hp/hr