On a sectional chart, a remote pilot sees a Restricted Area labeled 'R-5107A SFC–12,000.' The planned UAS flight will occur at 300 feet AGL near the boundary. What does this altitude notation tell the pilot?
- AThe restricted area extends from the surface up to 12,000 feet MSL, so the entire area is restricted airspace regardless of the UAS's low operating altitude.
- BUAS operating below 400 feet AGL are automatically excluded from restricted area boundaries.
- CThe restricted area is active only during nighttime hours, based on the altitude figures shown.
- DThe restriction only applies to aircraft flying above 12,000 feet MSL, so low-altitude UAS flights are unaffected.
Show answer & explanationAnswer & explanation
Correct answer: A. The restricted area extends from the surface up to 12,000 feet MSL, so the entire area is restricted airspace regardless of the UAS's low operating altitude.
The notation 'SFC–12,000' indicates the restricted area extends vertically from the surface (SFC) up to 12,000 feet MSL. Because the area includes the surface, any UAS flight within the lateral boundaries — even at low altitude such as 300 feet AGL — is within the restricted airspace and requires permission from the controlling agency.
Why the other options are wrong
- B. Low-altitude UAS are not automatically excluded; lateral boundaries and floor altitude (here, the surface) still apply.
- C. Altitude figures indicate vertical limits, not time-based activation; timing is found in separate charted or NOTAM data.
- D. This misreads 'SFC' as an upper limit rather than the floor of the restricted area.
Restricted Area Altitude Notation
Sectional charts show restricted area vertical limits as floor–ceiling values; 'SFC' means the restriction begins at ground level, so any altitude within the lateral boundary is restricted.
- 'SFC' = surface, the floor of the restricted airspace
- Ceiling value given in feet MSL
- Lateral boundaries plus floor/ceiling define restricted airspace
- Low-altitude UAS are not automatically exempt if floor is SFC
Memory trick: 'SFC means the floor is the ground' — no low-altitude loophole.