UA.II.B.K7: Ground structures and ground structure lighting.

ACS Area II — Airspace Classification and Operating Requirements Task B: Airspace Operational Requirements References: 14 CFRCode of Federal RegulationsCloseThe federal rulebook where Part 107, Part 89, Part 48, and other aviation rules live. part 71; ACAdvisory CircularCloseFAA guidance that explains acceptable ways to comply with rules or understand FAA procedures. 107-2; AIMAeronautical Information ManualCloseFAA operational guidance and glossary material used to understand aviation procedures and terminology.; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-H-8083-25; FAAFederal Aviation AdministrationCloseThe U.S. aviation regulator responsible for Part 107 rules, airspace, and pilot certification processes.-G-8082-22; SAFOSafety Alert for OperatorsCloseFAA safety alert that shares operational safety information. 10015

Key Concepts

Why “ground structures” matter to airspace operations

Remote pilots must understand how airport ground infrastructure and nearby surface areas interface with controlled airspace. Controlled airspace includes Class A, B, C, D, and E; uncontrolled is Class G. Class A generally spans from 18,000 feet MSLMean Sea LevelCloseAltitude measured from average sea level, not from the ground below you. up to and including FLFlight LevelCloseAltitude expressed using a standard pressure setting, mainly relevant to higher-altitude crewed aviation. 600; Class B often runs from the surface to 10,000 feet MSLMean Sea LevelCloseAltitude measured from average sea level, not from the ground below you.; a large portion of the NASNational Airspace SystemCloseThe shared U.S. airspace system that drones must operate within. is Class E. Class G extends from the surface to the base of the overlying Class E. In most areas, Class E begins at 1,200 feet AGLAbove Ground LevelCloseAltitude measured above the ground directly below the aircraft., but many locations start at 700 feet AGLAbove Ground LevelCloseAltitude measured above the ground directly below the aircraft. or the surface; where not depicted, Class E begins at 14,500 feet MSLMean Sea LevelCloseAltitude measured from average sea level, not from the ground below you. and typically extends up to, but not including, 18,000 feet MSLMean Sea LevelCloseAltitude measured from average sea level, not from the ground below you., with all airspace above FLFlight LevelCloseAltitude expressed using a standard pressure setting, mainly relevant to higher-altitude crewed aviation. 600 as Class E. These vertical limits frame how close aircraft operate to the ground and to ground structures that may affect your operations and risk picture near airports and populated areas^[1][2].

Airport ground structures you must not enter or damage

• Engineered Materials Arresting System (EMAS): EMASEngineered Materials Arresting SystemCloseCrushable runway safety material designed to help stop aircraft overruns. can be placed as close as 35 feet beyond a runway end. Aircraft and ground vehicles should never taxi or drive across EMASEngineered Materials Arresting SystemCloseCrushable runway safety material designed to help stop aircraft overruns. or beyond the runway end when EMASEngineered Materials Arresting SystemCloseCrushable runway safety material designed to help stop aircraft overruns. is present. For a remote pilot, this is a critical no-go surface: do not take off, land, or traverse EMASEngineered Materials Arresting SystemCloseCrushable runway safety material designed to help stop aircraft overruns. or the overrun just beyond runway ends. Staging or recovering a small UA near runway ends risks conflict with aircraft using the safety area EMASEngineered Materials Arresting SystemCloseCrushable runway safety material designed to help stop aircraft overruns. protects^[3].
• Security Identification Display Area (SIDA): SIDAs are limited-access ramp areas requiring a CFRCode of Federal RegulationsCloseThe federal rulebook where Part 107, Part 89, Part 48, and other aviation rules live. 49 Part 1542-compliant badge. Movement into or within a SIDASecurity Identification Display AreaCloseAn airport security area where identification and access rules apply. is prohibited without proper identification; airports must publish boundaries, access control measures, movement-control procedures (including required ID media), and notification signs. Individuals without proper ID observed entering a SIDASecurity Identification Display AreaCloseAn airport security area where identification and access rules apply. may be reported to TSATransportation Security AdministrationCloseThe U.S. transportation security agency; appears in airport security context. or airport security. For remote pilots supporting airport operations, this means you must obtain proper authorization and ID before entering or operating on ramps, and you should brief any crew or observers accordingly^[3].

Planning to avoid ground conflicts near busy airports

• VFRVisual Flight RulesCloseRules for flight using visual reference and minimum weather conditions. Flyway Planning Charts on the reverse of some TACs identify flyways using ground references to help VFRVisual Flight RulesCloseRules for flight using visual reference and minimum weather conditions. pilots plan routes under and around Class B flows. These are planning aids; they do not guarantee a traffic-free route. When operating beneath Class B, pilots must still establish and maintain communications while transiting any Class B, C, or D surface areas of the underlying airports. Practically, expect concentrated crewed traffic aligned with ground references and avoid operating small UASSmall Unmanned Aircraft SystemCloseA small drone plus the control and communication links used to operate it. along those visual corridors near major airports^[4].
• VFRVisual Flight RulesCloseRules for flight using visual reference and minimum weather conditions. corridors are “holes” through some Class B areas with defined vertical and lateral limits in which aircraft may operate without ATCAir Traffic ControlCloseThe system that manages controlled airspace, traffic flow, and aircraft separation services. clearance; they are surrounded on all sides by Class B and do not extend to the surface. Ground-level operations beneath such corridors can still be in busy terminal areas—situational awareness is essential to avoid conflicts with low-altitude traffic converging on visual landmarks^[4].
• Speed and proximity cues in Class D: Within 4 NMNautical MileCloseA distance unit used in aviation. One nautical mile is about 1.15 statute miles. of the primary airport of a Class D area, at or below 2,500 feet above the surface, aircraft are limited to 200 knots unless ATCAir Traffic ControlCloseThe system that manages controlled airspace, traffic flow, and aircraft separation services. authorizes otherwise. Combined with mandatory two-way communications with the tower for departures or arrivals when the tower is operating, expect dense, time-compressed traffic near airport surface areas. When a Class D tower is closed, the airspace reverts to Class E at the surface or to Class E to 700 feet AGLAbove Ground LevelCloseAltitude measured above the ground directly below the aircraft. with Class G to the surface, as listed in the Chart Supplement—traffic patterns may change with these transitions^[6].

Special activities and obstacle considerations near the surface

• Parachute operations: No person may make, or permit, a parachute jump in or into Class A, B, C, or D airspace without an authorization from the ATCAir Traffic ControlCloseThe system that manages controlled airspace, traffic flow, and aircraft separation services. facility having jurisdiction. Remote pilots near drop zones should anticipate rapid descents and coordinate operations to remain clear of these ground-associated activities^[5].
• IFR obstacle clearance highlights ground risk: For IFRInstrument Flight RulesCloseRules for operating primarily by instruments. On the exam, IFR often appears in weather, traffic, and airspace context. operations, aircraft must remain at least 1,000 feet (2,000 feet in designated mountainous terrain) above the highest obstacle within 4 NMNautical MileCloseA distance unit used in aviation. One nautical mile is about 1.15 statute miles. of course. While an IFRInstrument Flight RulesCloseRules for operating primarily by instruments. On the exam, IFR often appears in weather, traffic, and airspace context. rule, it underscores why tall ground structures near flight paths are critical hazards that demand wide berth and strong visual scanning from remote pilots operating near terrain and man-made obstacles^[7].
• Offshore Class E areas extend upward from a specified altitude to, but not including, 18,000 feet MSLMean Sea LevelCloseAltitude measured from average sea level, not from the ground below you. beyond 12 miles offshore, where domestic procedures apply—important when maritime ground structures (e.g., platforms) overlap IFRInstrument Flight RulesCloseRules for operating primarily by instruments. On the exam, IFR often appears in weather, traffic, and airspace context. routes in controlled airspace^[7].

Understanding where ground infrastructure, secured areas, and terminal airspace surfaces meet helps you choose launch sites, maintain safe separation from airport movement areas, and anticipate crewed traffic that aligns with ground references and lighting on or near airports.