Pilot Rules Of Thumb

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

Altimeter correction for non-standard temperature

'From high to low, look below'

Corr (feet) = 4 x Δ ISA x altitude (feet)

                                              1000

FL 300 ISA - 6°C

Corr = 4 x 6 x 30 = 680 feet

Alt = 29320 feet

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

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

Level Off procedure if R/C ≤ 1000 feet/min (also for descent R/D)

Δ feet = R/C (feet/min)

10

Climbing to FL 210 R/C = 2000 feet/min

Δ feet = 200 feet ô€ƒ† start level off at 20800 feet

Level Off procedure if R/C > 1000 feet/min (also for descent R/D)

Δ feet = 2 x R/C (feet/min)

                          10

Climbing to FL 300 R/C = 2500 feet/min

Δ feet = 500 feet ô€ƒ† start level off at 29500 feet

Cruise Flight Level computation

CruiseFL= Trip Distance (NM)

EBBR-EBOS = 60 NM

Optimum is FL 60

Vertical Speed to rejoin assigned altitude

V/S (feet/min) = 2 x Δ feet

If on 6250 feet instead of 6000 feet, correct with V/S = 500 feet/min

To obtain TAS out of Mach-number (high altitudes - cruise)

TAS (kt) = 6 x Mach

M 0.72

TAS = 420 kt

To find TAS out of IAS and FL

TAS (kt) = IAS (kt) + FL

                                   2

FL 300 IAS = 240 kt

TAS = 240 + 150 = 390 kt

Ground Speed out of Mach

GS (NM/min) = 10 x Mach

M 0.72

GS = 7,2 NM/

Drift computation in cruise

Drift (°) = X-wind (kt)

                   Mach

M 0.7 X-wind 35 kt

Drift = 35 / 7 = 5°

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°

To find Ground Speed with DME station available

GS (kt) = 100 x distance (NM) in 36s

Read distance covered in 36 seconds towards or away from station

Off-Track distance

Off-Track Distance = Δ° 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

 Intercepting outbound leg when close to the VOR-DME station (valid for Mach 0.7)

1 NM for each Δ30°

FL 330 Inbound on R-180 (Hdg N) to track 060 outbound

Start your turn to 060 at 2 NM before (+ slant 5.5NM)

Intercept Heading when passing over station before turning to outbound Heading

Attack (°) = 1/3 x ΔTrack (°)

Inbound on 180 (Hdg N) to track 060 outbound

Take Heading 080 overhead Station to intercept Radial

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

Top of Descent (Idle thrust - 3° descent path)

TOD (NM) = Δ FL

                       3

FL 280 down to 2000 feet

TOD = 260 / 3 = 87 NM

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

Vertical speed by changing Body Attitude (valid for high speeds)

R/D (feet/min) = Mach x ΔBA (°)

Mach 0.74 􀃆 One degree BA results in 740 feet/min

Vertical speed by changing Body Attitude (valid for lower speeds)

Use TAS or IAS in approach

R/D (feet/min) = speed number x ΔBA (°)

Speed TAS 420 kt BA 3 degrees down

R/D = 7 x 3 = 2100 feet/min