RULES OF THUMB

DESCENT PLANNING FOR 3 DEGREE GLIDE SLOPE

Rate of descent = Airspeed x 5 Example :: 100 Kts x 5 = 500 ft/min

Distance for descent is height change x 3 Example: descend from 7,000ft to 1,000ft (6,000ft) 6 x 3 = 18nm. Start descent 18nm

TAKE OFF DISTANCE INCREASE

10% each 1,000ft altitude and 10 degrees above ISA or 10% up slope or dry grass

20% if weight up 10%

30% wet grass

LANDING DISTANCE INCREASE

5% each 1,000ft altitude or 10 degrees above ISA

10% if weight up 10% or 10% down slope or dry grass

30% wet grass

DENSITY ALTITUDE 1 Cº over ISA = 120FT (plus height over ground)

Example: Eastern 180FT. OAT 35º = 2,400FT + height 180FT = 2,580FT Density Altitude

TRUE AIRSPEED is indicated airspeed + 2% each 1,000FT

Example 100 Kts indicated at 5,000FT is 100 + 2% x 5 = 110 Kts TAS. (Caution over Vne)

ALTIMETER ERROR 4FT x temp deviation from ISA X height (1000)

Example OAT is 20 deg at 5,000FT. But ISA is 5 (difference 15 deg) 4 x 15 x 5 = 300FT.

Altimeter under-reads 300FT. True altitude 5,300FT. Caution- below ISA, altimeter over-reads

WIND COMPONENTS

	CROSS	HEAD
15 º	25%	95%
30 º	50%	90%
45 º	70%	70%
60 º	90%	50%
75 º	95%	25%
Example 10Kt from 30º is 5Kt cross/w and 9Kt headwind

NAVIGATION - OFF TRACK 1 in 60 rule : 1 degree off track is 1nm in 60

Distance off track / (divided by) distance gone x 60 = track error in degrees

Distance off track / (divided by) distance to go x 60 = closing angle. (Add together)

BEST SPEED (Lift/Drag) for max Range / Rate of Climb / Glide is stall speed clean x 1.4

Example: stall speed 50 Kts x 1.4 = 70 Kts. Best speed if low on fuel or gliding engine out.

COORDINATES eg 12.45.30 N Degrees / minutes / seconds

1 Degree = 60 nm or 110 Km Example 13.45.30 is 60 miles north

1 Minute = 1 nm about 2 Km Example 12.46.30 is 1 mile north

1 Second = 30 metres Example 12.45.40 is 300m north