FAA Sport Pilot Airplane (SPA)WeatherHard
On a surface analysis chart, a station model shows a wind barb with one full-length flag line and one half-length flag line extending from the wind direction shaft. What wind speed does this barb represent?
- A15 knots
- B10 knots
- C20 knots
- D5 knots
Show answer & explanationAnswer & explanation
Correct answer: A. 15 knots
On a station model, each full barb represents 10 knots and each half barb represents 5 knots; one full barb plus one half barb equals 15 knots total.
Why the other options are wrong
- B. 10 knots would be shown by a single full barb alone.
- C. 20 knots would require two full barbs with no half barb.
- D. 5 knots would be shown by a single half barb alone.
Wind Barb Symbols
Station models depict wind speed using barbs: a half barb equals 5 knots, a full barb equals 10 knots, and a pennant (triangle) equals 50 knots.
- No barbs (just shaft) = calm or very light wind
- Barbs are read and summed along the shaft
- Pennant = 50 kt, full barb = 10 kt, half barb = 5 kt
Memory trick: Full barb = 'Ten-foot flag'; half barb = 'Five-foot flag'.