Navigation & flight planning

Formulas appendix061 / 033 / 062

061 General navigation

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Departure (E/W) NM = Δ longitude (minutes) × cos(latitude)

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Earth convergency = Δ longitude × sin(mean latitude) | Conversion angle = ½ convergency

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Mercator scale = scale × or ÷ cos(Δ latitude) — multiply from equator, divide toward equator

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Lambert convergency = Δ longitude × sin(parallel of origin)

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Grid: convergence = Δ longitude from datum; grivation = variation + convergence

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1-in-60: track error (°) = off-track distance × 60 / distance flown

033 Flight planning

Formula —

PET distance from departure: X = (D × H) / (O + H) — D = total distance, H = GS home, O = GS out

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PSR distance from departure: X = (E × O × H) / (O + H) — E = safe endurance (hours, decimal)

Formula —

Alternative PSR: X = E / (SFC out + SFC home)

Key fact

PET moves into wind. PSR greatest distance in still air. For OEI: use OEI GS for distance; AEO TAS for PET time.

Formula —

Best range (jet) = 1.32 × VIMD | SAR (jet) = TAS / (SFC × drag)

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NAM × TAS = NGM × GS | NGM = NAM ± (WC × time / 60)

062 Radio navigation

Formula —

VHF range (NM) ≈ 1.25√(h₁) + 1.25√(h₂) — heights in feet

Formula —

NDB max range (NM) ≈ 3 × √power (watts)

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Wavelength λ = c / f

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Radar max range (m) = (c / PRF) × 2 | Min range = (c × pulse length) / 2

Formula —

Beamwidth (°) ≈ 70 × λ / antenna diameter

Key fact

Q codes: QUJ = true to station, QTE = true from, QDR = magnetic from (radial), QDM = magnetic to.