Units

JSBSim uses English units for internal calculations almost exclusively. However, it is possible to input some parameters in the configuration file using different units. In fact, to avoid confusion, it is recommended that the unit always be specified. Units are specified using the unit attribute. For instance, the specification for the wingspan looks like this:

<wingspan unit="FT"> 35.8 </wingspan>

The above statement specifies a wingspan of 35.8 feet. The following statement specifying the wingspan in meters would result in the wingspan being converted to 35.8 feet as it was read in:

<wingspan unit="M"> 10.91 </wingspan>

The two statements for wingspan are effectively equivalent.

The following units are currently supported in JSBSim:

Length

unit=	unit
FT	ft
IN	in
M	m
KM	km

Area

unit=	unit
M2	m²
FT2	ft²

Volume

unit=	unit
FT3	ft³
CC	cm³
M3	m³
LTR	l

Mass and Weight

unit=	unit
LBS	lbm
KG	kg

Moments of Inertia

unit=	unit
SLUG*FT2	slug ft²
KG*M2	kg m²

Angles

unit=	unit
RAD	rad
DEG	deg

Spring Force

unit=	unit
N/M	N/m
LBS/FT	lb/ft

Damping Force

unit=	unit
N/M/SEC	N/(m s)
LBS/FT/SEC	lb/(ft s)

Power

unit=	unit
WATTS	W
HP	Hp

Force

unit=	unit
LBS	lb
N	N

Velocity

unit=	unit
KTS	kts
FT/SEC	ft/s
M/S	m/s

Torque

unit=	unit
N*M	N m
FT*LBS	lb ft

Pressure

unit=	unit
PSF	lb/ft²
PSI	lb/in²
ATM	atm
PA	N/m²
INHG	in HG