FAA Private Pilot Helicopter (PRH)Navigation and AirspaceHard
A pilot computes a true course of 270° with a 4° right wind correction angle, resulting in a true heading of 274°. The local magnetic variation is 6°W, and the compass deviation card shows -2° for that heading. What is the compass heading?
- A284°
- B272°
- C278°
- D280°
Show answer & explanationAnswer & explanation
Correct answer: C. 278°
West variation is added to true heading: 274° + 6° = 280° magnetic heading. Then applying the deviation of -2° gives 280° - 2° = 278° compass heading.
Why the other options are wrong
- A. This incorrectly adds the deviation instead of subtracting it.
- B. This results from subtracting variation instead of adding it for West variation.
- D. This is the magnetic heading before deviation is applied, not the final compass heading.
True Course to Compass Heading
Converting true course to compass heading requires sequentially applying wind correction angle, magnetic variation (East subtract, West add), and compass deviation.
- TC + WCA = TH
- TH + West variation (or - East) = MH
- MH + deviation (algebraic) = CH
- Memory aid: 'East is Least, West is Best' for variation
Memory trick: East is Least, West is Best — add west variation, subtract east.