UAS Navigation 3 — Questions and Answers
Question 1: A remote pilot notes that isogonic lines on a sectional chart show '10°E' variation. If the magnetic compass reads 270°, what is the true heading?
- 260°
- 280° (Correct answer)
- 270°
- 290°
Correct answer: 280°
With 10°E variation, true heading = magnetic heading + easterly variation = 270° + 10° = 280°.
Question 2: Which chart scale is most useful for detailed local navigation by a sUAS remote pilot?
- 1:500,000 (sectional chart)
- 1:1,000,000 (world aeronautical chart)
- 1:250,000 (terminal area chart) (Correct answer)
- 1:2,000,000 (en route chart)
Correct answer: 1:250,000 (terminal area chart)
Terminal area charts at 1:250,000 scale provide the greatest detail for operations near busy metropolitan airports.
Question 3: What does a blue segmented line on a sectional chart typically represent?
- Class G airspace boundary
- Class B airspace boundary
- Class E airspace starting at 1,200 ft AGL
- Victor airway centerline (Correct answer)
Correct answer: Victor airway centerline
Blue segmented lines on sectional charts depict Victor airways, which are low-altitude airways centered on VOR stations.
Question 4: A sUAS pilot wants to fly 5 miles north of the launch point. Using a sectional chart, approximately how many minutes of latitude must they travel?
- 1 minute
- 5 minutes (Correct answer)
- 10 minutes
- 30 minutes
Correct answer: 5 minutes
One minute of latitude equals approximately one nautical mile, so 5 nautical miles north equals approximately 5 minutes of latitude.
Question 5: In GPS navigation, what does HDOP (Horizontal Dilution of Precision) measure?
- The signal strength of each GPS satellite
- The geometric quality of satellite positioning affecting horizontal accuracy (Correct answer)
- The number of satellites in view
- The altitude error of the GPS receiver
Correct answer: The geometric quality of satellite positioning affecting horizontal accuracy
HDOP reflects how satellite geometry affects horizontal position accuracy; a lower HDOP value means better geometric spread and higher accuracy.
Question 6: When a sUAS experiences compass interference from nearby metal structures, the pilot should primarily rely on which navigation method?
- Pressure altitude readings
- GPS-derived heading and position (Correct answer)
- Dead reckoning using estimated wind drift
- ATC radar advisories
Correct answer: GPS-derived heading and position
GPS provides independent position and track information that is not affected by local magnetic interference from metal structures.
Question 7: What information does a sectional chart legend provide regarding color-coded airspace?
- The phone numbers of controlling ATC facilities
- The meaning of airspace class depictions, symbols, and chart features (Correct answer)
- Real-time NOTAM information
- Sunrise and sunset times for the chart area
Correct answer: The meaning of airspace class depictions, symbols, and chart features
The sectional chart legend explains the symbols, colors, and depictions used throughout the chart, including airspace class boundaries.
UAS Navigation 3
A remote pilot notes that isogonic lines on a sectional chart show '10°E' variation.
If the magnetic compass reads 270°, what is the true heading?