Units of Measurement to Be Used in Air and Ground Operations

SUBPARTA-GENERAL#

§ 2.1 Purpose.#

This part prescribes the units of measure to be used in air and ground operations related to civil aviation in the Kingdom of Saudi Arabia.

§ 2.3 Units of Measure.#

(a) Except as provided in GACAR § 2.5 , the definitions and applications of units of measurement for air and ground operations as specified in this part are adapted based on the International System of Units (SI) developed and maintained by the General Conference of Weights and Measures (CGPM).

(b) The prefixes and symbols listed in Appendix A of this part are used to form names and symbols of the decimal multiples and submultiples of SI units.

Note: The Gregorian calendar is used in the GACARs.

GACAR PART 2 -UNITS OF MEASUREMENT TO BE USED IN AIR AND GROUNDOPERATIONS#

§ 2.5 Use of Non-SI Units.#

(a) The non-SI units listed in Appendix B, Table 1 of this part are used either in lieu of, or in addition to, SI units as primary units of measurement but only as specified in the Appendix B Table 2.

(b) The non-SI units listed below are permitted for temporary use as alternative units of measurement but only for those specific quantities listed in Appendix B - Table 2.

Specific quantities in Table 3-4 related to	Unit	Symbol	Definition (in terms of SI units)
distance (long)	nautical mile	NM	1 NM = 1 852 m
Elevation/Distance (vertical)	foot	ft	1 ft = 0.304 8 m
Speed (horizontal)	knot	kt	1 kt = 0.514 444 m/s
Speed (vertical)	feet per minute	ft/min

§ 2.7 Application of specific units#

(a) The application of units of measurement for certain quantities used in international civil aviation air and ground operations must be in accordance with Appendix B - Table 2.

(b) Aviation organizations must establish means and provisions for design, procedures and training for application and operations in environments involving the use of standard and non-SI alternatives of specific units of measurement, or the transition between environments using different units, with

GACAR PART 2 - UNITS OF MEASUREMENT TO BE USED IN AIR AND GROUNDOPERATIONS#

due consideration to human performance.

(c) The application of non-SI unit, knot / nautical mile and foot in any operational environment will continue to be effective as per the provisions of this part unless and until notified by the president based on safety assessment if any further revisions are incorporated by the International Civil Aviation Organization.

GACAR PART 2 - UNITS OF MEASUREMENT TO BE USED IN AIR AND GROUNDOPERATIONS#

Multiplication factor	Prefix	Symbol
1 000 000 000 000 000 000 =1018	exa	E
1 000 000 000 000 000 = 1015	peta	P
1 000 000 000 000 = 1012	tera	T
1 000 000 000 = 109	giga	G
1 000 000 = 106	mega	M
1 000 = 103	kilo	k
100 = 102	hecto	h
10 = 101	deca	da
0.1 = 10-1	deci	d
0.01 = 10-2	centi
0.001 = 10-3	milli	m
0.000 001 = 10-6	micro	H
0.000 000 001 = 10-9	nano	n
0.000 000 000 001 = 10-12	pico	P
0.000 000 000 000 001 = 10-15	femto
0.000 000 000 000 000 001 = 10-18	atto	a

Specific quantities in Table 3-4 related to	Unit	Symbol	Definition (in terms of SI units)
mass	tonne	t	1 t = 10² kg
plane angle	degree minute		1° = (π/180) rad 1' =(1/60)° =(π/10 800) rad
temperature	second degree Celsius	°C	1" =(1/60)' = (π/648 000) rad 1 unit °C = 1 unit K
time	minute hour	min h	1 min = 60 s 1 h = 60 min = 3 600 s
	fep week, month, year	d	1 d=24 h= 86 400 s
volume	litre	L	1 L=1 dm²=10-m²

Ref No.	Quantity	Primary unit (symbol)	Non-SI altermative unit (symbol)
1. Direction/Space/Time
1.1	altitude	fm	f
1.2	afea	m2
1.3	distance (long)a)	km	NM
1.4	distance (short)	m
1.5	elevation	m	f
1.6	endurance	h and min
1.7	height	fm	f
1.8	latitude
1.9	length	fm1
1.10	longitude	i1 0
1.11	plane angle (when required, decimal subdivisions of the degree
shall be used)		D
1.12	nunway length	fm
1.13 1.14	runway visual range tank capacities (aircraft)b)	fm
		L
2. Mass Related
2.1	air density	kg/m3
2.2	area density	kg/m2
2.3	cargo capacity	kg
2.4	cargo density	kg/m3
2.5	density (mass density)	kg/m3
2.6	fuel capacity (gravimetric)	kg
2.7	gas density	kg/m3
2.8	gross mass or payload	kg
		t
2.9	hoisting provisions	kg
2.10	linear density	kg/m
2.11	liquid density	kg/m3
2.12	mass	kg
2.13	moment of inertia	kg. m2
2.14	Movement of momentum	kg.m2/s
2.15	momentum	kg. m/s

3. Force-related kPa
3.1 3.2	air pressure (general)
altimeter setting	hPa
3.3 atmospheric pressure	hPa
3.4 bending moment	kN · m
3.5 force	N
3.6 fuel supply pressure	kPa
3.7 hydraulic pressure	kPa
3.8 modulus of elasticity	MPa
3.9 pressure	kPa
3.10 stress	MPa
3.11 surface tension	mN/m
3.12 thrust	kN
3.13 torque	N ·m
3.14 vacuum	P

Standard application of other specific units of measurement with respect to mechanical units (mechanic), flow, and thermodynamics; electricity and magnetism, light and related electromagnetic radiations, acoustics and nuclear physics and ionizing radiation are in accordance with the Annex 5, Table 3-4, Standard application of specific units of measurement.