2.4 EVLOS and Sheltered Operations

2.4 EVLOS and Sheltered Operations

Quick Answer: Sheltered (small only): fly around a building/structure without direct VLOS and without a visual observer—≤100 ft (30 m) above the structure, within 200 ft (61 m) horizontally of it, within 3.7 km (2 NM) of pilot and control station, pilot/GCS at the take-off/landing site for those phases, and ≥100 ft (30 m) from uninvolved persons. EVLOS (small only, uncontrolled airspace): not in pilot VLOS, but a trained VO with at least a Basic certificate watches airspace; ≥100 ft (30 m) from persons; aircraft within 3.7 km of pilot, GCS, and VO.

These two privileges are the Advanced certificate's answer to "I need to go briefly behind something" or "I need a trained extra set of eyes for a short-range non-VLOS segment"—without stepping fully into Level 1 Complex BVLOS. Both are small-drone privileges under the Advanced operations framework published by Transport Canada (page modified 2026-03-19). Medium RPAS are not granted sheltered or EVLOS under these Advanced small-only rules.

Why these privileges exist

Classic VLOS means the pilot (or a properly used visual observer arrangement under general VLOS rules) can see the aircraft well enough to control it, detect other aircraft, and avoid hazards. Real missions—roof inspections on the far side of a warehouse, corridor flights along a tree line, short pipeline segments—often push the aircraft just out of the pilot's unaided sight while remaining close to infrastructure. Sheltered and EVLOS create tight, standardized boxes for those missions so risk stays bounded.

They are not:

• Unlimited BVLOS across kilometres of countryside
• A way to overfly crowds without near/over-people declarations
• A medium-aircraft privilege set
• A substitute for ATC authorization when the operation is in controlled airspace (sheltered in controlled airspace still engages controlled-airspace requirements and the 922.04 declaration path)

Sheltered operations (small drones only)

Transport Canada defines sheltered operations as flying a small drone around a building or structure without maintaining direct visual line-of-sight and without the use of a visual observer. The structure "shelters" the operation by constraining where the aircraft may be relative to that object.

Hard limits (memorize exactly)

Declaration note for sheltered in controlled airspace

The Advanced operations table lists Sheltered Operation in Controlled Airspace against Standard 922.04 with a Declaration under CAR 901.69(d). If your sheltered mission is in controlled airspace, treat aircraft eligibility and ATC permission with the same seriousness as other controlled-airspace advanced flights. Do not assume "I'm only beside a building" removes airspace coordination.

Operational picture

Imagine inspecting the far façade of a 20 m warehouse. The pilot stands at a designated pad on the near side. The aircraft climbs no more than 30 m above the warehouse roof line and stays within 61 m horizontally of the building while it wraps around. Uninvolved persons are kept at least 30 m away. The pilot never lets the aircraft wander into open space far from the structure—that would exit the sheltered geometric box even if C2 is solid.

If you need a visual observer, long open-area transit, or flight far from any structure, sheltered is the wrong privilege—look at VLOS with VO, EVLOS, or Complex/BVLOS paths as appropriate.

Extended visual line-of-sight (EVLOS) (small drones only)

EVLOS means flying a small drone that is not in visual line-of-sight of the pilot, while using a trained and certified visual observer who watches the surrounding airspace well enough to detect and avoid other aircraft or hazards.

Conditions

• Small drone only
• Uncontrolled airspace only (EVLOS is not the Advanced controlled-airspace BVLOS solution)
• Visual observer must hold at least a Basic drone pilot certificate
• At least 100 ft (30 m) away from any person (uninvolved persons—maintain the 30 m horizontal people floor stated for EVLOS)
• Keep the drone within 3.7 km (two nautical miles) from the pilot, the control station, and the visual observer at any time during the flight

That third range vertex is easy to miss: EVLOS caps range relative to three points (pilot, GCS, VO), not only the pilot. If the VO is poorly positioned, the aircraft can leave the VO's 3.7 km bubble even while still inside the pilot's.

Visual observer role

The VO is not a casual spotter with a phone. Under EVLOS, the observer is the primary airspace watch because the pilot cannot see the aircraft. The VO needs:

• At least Basic certification (Advanced is fine, but Basic is the stated minimum)
• Training on the mission, radio phraseology with the pilot, scan techniques, and lost-link / traffic callouts
• A position with a clear view of the relevant airspace volume, not buried behind the same obstruction that hides the aircraft from the pilot without improving traffic detection

Crew resource management (briefing, sterile periods during critical phases, explicit transfer of traffic responsibility) is examinable human-factors material that pairs with EVLOS scenarios.

C2 link and lost-link concerns

When the pilot cannot see the aircraft, command-and-control (C2) performance and lost-link behaviour stop being background technical topics and become the flight's safety spine.

Plan for:

• Link margin. Trees, metal buildings, and terrain that create a sheltered geometry also create multipath and shielding. Walk the route with a spectrum-aware mindset; do not assume open-field range figures.
• Latency and control quality. EVLOS still requires the pilot to control the aircraft; if the link is marginal, do not enter the non-VLOS segment.
• Lost-link profile. Know whether the aircraft hovers, climbs, returns-to-home, or lands—and whether that profile keeps it inside the sheltered box or EVLOS 3.7 km bubbles and away from people and manned aircraft.
• RTH geometry. Return-to-home straight-line paths can exit a sheltered structure buffer or fly over uninvolved persons. Program and brief RTH points that respect the privilege you are using.
• Dual redundancy where available. Dual C2, dual GNSS, and clear fail-safes are operational mitigations even when not every flight legally requires Complex-level 922.09 declarations.

CAR themes around 901.74 / 901.75 (extended and sheltered operational rule families in Part IX) reinforce that these modes are regulated privileges with prescribed conditions—not informal workarounds. On the exam, if a choice describes EVLOS or sheltered without the numeric limits or VO/certification pieces, treat it as incomplete.

Sheltered vs EVLOS vs Complex BVLOS (comparison)

Exam scenario patterns

1. Wrong size. Medium aircraft "sheltered" behind a hangar → not under small-only sheltered privilege.
2. Missing VO on EVLOS. Pilot alone, aircraft beyond VLOS in Class G → fails EVLOS (needs certified VO).
3. EVLOS in controlled airspace. Advanced page scopes EVLOS to uncontrolled airspace; do not invent controlled-airspace EVLOS under Advanced alone.
4. Structure escape. Aircraft 150 m from the building while "sheltered" → exceeds 61 m horizontal structure limit.
5. Altitude above structure. 50 m above the roof → exceeds 30 m-above-structure limit.
6. People. Either mode with uninvolved persons at 10 m → fails the 30 m people floor stated for these privileges.
7. Range. Aircraft 4 km from the VO on EVLOS → exceeds 3.7 km (2 NM).

Drill those failures and the correct numeric limits until recall is automatic—TP 15263 Advanced air-law items reward precise regulatory geometry, not vague "stay close to the building" paraphrases.

Pre-flight briefing template (use on the written exam and on the job)

• Privilege selected: sheltered or EVLOS (not both muddled).
• Structure identity / VO position and credentials.
• Numeric limits card: 30 m above structure, 61 m from structure, 3.7 km range bubbles, 30 m people.
• C2 contingency and lost-link landing point inside the privilege box.
• Abort triggers: person intrusion, traffic call, link degradation, wind limits, battery minimums.
• Documents: Advanced pilot certificate, registration, declared model if required for the airspace/mode, site survey notes.

Fly the box you briefed. If the mission no longer fits the box, climb back into ordinary VLOS or seek the correct higher authority—do not stretch sheltered or EVLOS into de-facto BVLOS.