AVIATION RULES OF THUMB
The following information is provided as a guideline for better flying.
Use this information at your own risk. Nothing is written in stone here.
1) Altimeter correction for non-standard pressure
'From high to low, look below'
1 mb = 30 feet
FL 270 QNH 977
ISA - 36 mb ???? 36 x 30 = 1080 feet
Altitude = 25920 feet
2) Altimeter correction for non-standard temperature
'From high to low, look below'
Corr (feet) = 4 x ? ISA x altitude (feet)
1000
FL 300 ISA - 6°C
Corr = 4 x 6 x 30 = 680 feet
Alt = 29320 feet
3) SAT out of TAT
SAT (°C) = TAT (°C) - 3 x Mach
TAT = -17 °C Mach 0.64
SAT = -17 – 3 x 6 = -17 - 18 = -35 °C
4) SAT out of TAT for higher Mach and lower Temp
SAT (°C) = TAT (°C) - (100 x Mach) - 50
TAT = -31 °C Mach 0.74
You have 24 above M 0.50
SAT = -31 -24 = -55 °C
5) Level Off procedure if R/C ? 1000 feet/min (also for descent R/D)
? feet = R/C (feet/min)
10
Climbing to FL 210 R/C = 2000 feet/min
? feet = 200 feet ???? start level off at 20800 feet
6) Level Off procedure if R/C > 1000 feet/min (also for descent R/D)
? feet = 2 x R/C (feet/min)
10
Climbing to FL 300 R/C = 2500 feet/min
? feet = 500 feet ???? start level off at 29500 feet
7) Cruise Flight Level computation
NO OFFICIAL USE -ACCURACY CANNOT BE GUARANTEED - FOR INFO ONLY !
Cruise FL = Trip Distance (NM)
EBBR-EBOS = 60 NM
Optimum is FL 60
8) Vertical Speed to rejoin assigned altitude
V/S (feet/min) = 2 x ? feet
If on 6250 feet instead of 6000 feet, correct with V/S = 500 feet/min
9) To obtain TAS out of Mach-number (high altitudes - cruise)
TAS (kt) = 6 x Mach
M 0.72
TAS = 420 kt
10) To find TAS out of IAS and FL
TAS (kt) = IAS (kt) + FL
2
FL 300 IAS = 240 kt
TAS = 240 + 150 = 390 kt
11) Ground Speed out of Mach
GS (NM/min) = 10 x Mach
M 0.72
GS = 7,2 NM/min
NO OFFICIAL USE -ACCURACY CANNOT BE GUARANTEED - FOR INFO ONLY !
12) Drift computation in cruise
Drift (°) = X-wind (kt)
Mach
M 0.7 X-wind 35 kt
Drift = 35 / 7 = 5°
13) Drift computation out of TAS (not IAS, unless during approach)
Drift (°) = X-wind (kt) .
speed number
TAS 180 kt X-wind 36 kt
Drift = 36 / 3 = 12°
14) To find Ground Speed with DME station available
GS (kt) = 10 x distance (NM) in 36s
Read distance covered in 36 seconds towards or away from station
15) Off-Track distance
Off-Track Distance = ?° x distance to station
60
9° off track 11 NM from station
Off-Track Distance = 9 x 11 / 60 = 99 / 60 = 1.6 NM
16) Slant distance overhead a DME – station
each 6000 feet altitude ???? 1 NM DME
Overhead station FL 330
you will read 33000 / 6000 = 5.5 NM on DME
17) Intercepting outbound leg when close to the VOR-DME station (valid for Mach 0.7)
1 NM for each ?30°
FL 330 Inbound on R-180 (Hdg N) to track 060 outbound
Start your turn to 060 at 2 NM before (+ slant 5.5NM)
18) Intercept Heading when passing over station before turning to outbound Heading
Attack (°) = 1/3 x ?Track (°)
Inbound on 180 (Hdg N) to track 060 outbound
Take Heading 080 overhead Station to intercept Radial
19) Intercept Heading when a little bit off-track
Attack (°) = 3 x Off-Track angle (°)
On R-310 outbound instead of R-315
Take attack 15° to rejoin
20) Top of Descent (Idle thrust - 3° descent path)
TOD (NM) = ? FL
3
FL 280 down to 2000 feet
TOD = 260 / 3 = 87 NM
21) R/D required to be down at certain point
R/D (feet/min) = speed number x altitude (feet)
distance (NM)
Descent 17000 feet in the next 28 NM TAS 240 kt
R/D = 4 x 17000 / 28 = 2400 feet/min
22) Vertical speed by changing Body Attitude (valid for high speeds)
R/D (feet/min) = Mach x ?BA (°)
Mach 0.74 ???? One degree BA results in 740 feet/min
23) Vertical speed by changing Body Attitude (valid for lower speeds)
Use TAS or IAS in approach
R/D (feet/min) = speed number x ?BA (°)
Speed TAS 420 kt BA 3 degrees down
R/D = 7 x 3 = 2100 feet/min
NO OFFICIAL USE -ACCURACY CANNOT BE GUARANTEED - FOR INFO ONLY !
24) Distance required if you want to maintain a certain R/D profile
Distance (NM) = speed number x altitude (feet)
R/D
Descent 23000 feet at 1000 feet/min TAS 300 kt
Distance = 5 x 23 = 115 NM
25) Wind correction for descent distance
Wind Corr (NM) = 10% for each 40 kt component
Example Thumbrule 20) with 20 kts Tailwind
Add 58 to 87 = 92 NM
26) R/D required to follow a certain glide %
R/D (feet/min) = Ground Speed (kt) x %
TAS 350 kts 20 kts tailwind Glide 3° = 5%
R/D = 370 x 5 = 1850 feet/min
27) Conversion % versus degrees for glide path
% = 10 x degrees
6
ILS 3° Glide Slope ???? 30 / 6 = 5%
28) Start the roll-out from a turn when
?Heading (°) to go = Bank (°)
3
Bank 25° Right turn to Hdg 080
Start roll-out 8° in advance, thus on Hdg 072
29) Amount of Bank required for a turn
Bank (°) = ? Heading (°)
Heading North Right to Heading 007
Take 7° Bank
30) Bank required for a rate one turn
Bank (°) = 15% TAS (kt)
TAS 180 kt Rate one turn
Bank = 18 + 9 = 27°
31) Turn diameter of a rate one turn
Diameter (NM) = TAS (kt)
100
TAS 150 kt
Turn ? = 1,5 NM
32) Outbound timing for a base turn, when not mentioned on the chart
Time (min) = 36 .
?Track
ILS Rwy 27 (QFU 270) Teardrop 066 outbound
Time = 36 / (090-066) = 1,5 min
33) R/D to follow the glide slope ILS 3° = 5%
R/D (feet/min) = 5 x Ground Speed (kt)
On Glide Slope TAS 140 kt 10 kt Tailwind
R/D = 750 feet/min
34) Visibility required to see threshold at VDP (Non-Precision Approach)
Vis (m) = 6 x MDA (feet)
MDA 430 feet
Visibility = 6 x 430 feet = 2500 m
35) Memorize this table 1/60 speed (kt)
Second number is Speed in Miles Per Minute
120 = 2
150 = 2.5
180 = 3
210 =3.5
240 = 4
270 = 4.5
300 = 5
330 = 5.5
