FAA Part 107 Remote Pilot (UAG)OperationsHard
A remote pilot is conducting a sUAS aerial survey near a location with a high concentration of radio towers and power lines. During the flight, the sUAS exhibits erratic behavior, including unexpected changes in altitude and heading, despite stable GPS reception. What is the most likely cause of this behavior?
- ALoss of GPS signal due to signal obstruction.
- BA sudden, unforecasted wind shear event.
- CElectromagnetic interference (EMI) affecting the sUAS's internal compass or other sensors.
- DAerodynamic turbulence caused by the structures.
Show answer & explanationAnswer & explanation
Correct answer: C. Electromagnetic interference (EMI) affecting the sUAS's internal compass or other sensors.
High concentrations of radio towers and power lines are significant sources of electromagnetic interference (EMI). While GPS is stable, EMI can disrupt the sUAS's internal compass (magnetometer) and other sensitive electronic sensors. This disruption can lead the flight controller to receive erroneous data, resulting in erratic flight behavior as it tries to compensate, even with a strong GPS signal.
Why the other options are wrong
- A. The scenario explicitly states 'stable GPS reception,' ruling out GPS signal loss.
- B. While possible, unforecasted wind shear would typically be described differently (e.g., sudden jolts, loss of control in a specific direction) and is less likely to cause erratic altitude and heading changes across multiple axes with stable GPS than EMI.
- D. Aerodynamic turbulence might cause some instability, but erratic changes in altitude and heading despite stable GPS are more indicative of sensor interference.
Electromagnetic Interference (EMI)
Disruption of electronic components or systems caused by electromagnetic fields from external sources, such as radio towers or power lines.
- Can affect sUAS compass, GPS, and other sensors.
- Leads to erratic flight behavior despite stable GPS.
- Common near power lines, radio antennas, and electrical equipment.
Memory trick: Erratic flight near towers? 'E'lectromagnetic 'M'ess 'I's the issue.