Equations

Equations, formulas, and other rule of thumbs

Formula	Equation	Notes
Mach number	TAS(True airspeed)/LSS(Local speed of sound)
Local speed of sound	Speed of sound (kts)= 38,94 * √T (Kelvin)
Lift	Lift = ½ρv²SCᴸ	Cᴸ= Coefficient of lift
Pressure altitude (PA)	Elevation + (1013 - QNH) (27) or Elevation + 1000 x (29.92 - altimeter setting)	QNH = Forecasted or reported pressure value
Density altitude (DA)	Pressure altitude + (OAT - ISA deviation) (120)	OAT = Outside air temperature & ISA = International standard atmosphere
Crosswind	Wind speed x sin wind angle
Headwind	Wind speed x cos wind angle
Rate one turn	3°/second	180° in one minute
G-force	1/cos (bank angle)
Magnetic bearing	Magnetic heading + Relative bearing = Magnetic bearing
Rotation speed VR	VS x 1.15	VS = Stall speed
Manouvre stall speed	VS x √n or VS x √1/cosα	VS = Stall speed

Radio navigation instruments, their frequencies, and range

Other rule of thumbs and useful info

Emergency frequencies	VHF 121.5, UHF 243, ELT 406
Squawk code for communications failure	7600
Squawk code for emergencies	7700
Squawk code for hijack	7500
Are winds in relation to magnetic or true north?	Both. Forecasted winds are true, reported winds are magnetic
Windsock	Each segment represent 3kts of wind
Over the threshold	At the threshold, 1/2 LOC dot = 1/2 runway width
Aircraft weight	10% of aircraft weight change will result in 20% change in take-off distance
Abort take-off	If 70% of takeoff speed is not acheived within 50% of runway
Takeoff distance for general aviation	You need to reach at least 70% of take-off speed by 50% of runway distance
For max TAS and range	Load airplane as close to the aft CG limit as allowable
VOR range (NM)	1.23 x √Altitude in feet
A tailwind of 10% of your approach speed	increase landing distance by 20%

Disclaimer: These rules of thumbs are not intended to be exact or precise! Use them for your information or at your own discretion