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Below you can find a summary of formulas which are used to solve the Questions on the topic "Navigation in climb and descent" and which can be useful for other topics aswel.
- Finding average TAS in a climb or descent
Climb: Take the average TAS at 2/3 altitude change
(Start altitude + (2/3 x Altitude change) )
Descent: Take the average TAS at half the altitude change
(Start altitude + End altitude) / 2
- Gradients
Gradient as FT/NM = Altitude change (feet) / Ground distance (NM)
Gradient as % = Altitude change (feet) / Ground distance (feet) x 100
Gradient as GP° = Altitude change (feet) x 60 / Ground distance (feet)
- From Gradient to Vertical Speed (VS)
Gradient FT/NM:
VS = Gradient x ( GS / 60 )
Gradient %:
VS = Gradient(%) x GS
Gradient GP:
(If 3°) = 5 x GS
(If not 3°) = 5 x GS x (x° / 3)
- Distance and time during a climb/descent
(Ground distance x 60) / GS = Time = altitude difference / VS
Which simply means;
Altitude need to climb/descent (D) / Vertical Speed (V) = Time (T)
Ground distance needed for this (D) = Ground speed (V) x Time (T)
In the second formula, remember that you can't just use '20' to mean minutes like in the first formula. Either divide it by 60 or use the degrees, minutes, seconds function on your calculator.
