6.2 Right-of-Way Rules, Altitudes, VFR Fuel Reserves & Inspections

Right-of-Way Rules, Altitudes, VFR Fuel Reserves & Inspections

Flight safety requires strict adherence to standardized traffic rules, clear separation profiles, conservative fuel planning, and disciplined maintenance scheduling. 14 CFR Part 91 establishes mandatory rules for aircraft right-of-way, minimum safe operating altitudes over various terrains, Visual Flight Rules (VFR) fuel reserves, and required periodic aircraft inspections.

Right-of-Way Rules (14 CFR 91.113)

Under 14 CFR § 91.113(a), regardless of right-of-way rules or ATC instructions, every pilot must maintain vigilance to see and avoid other aircraft. When weather permits, see-and-avoid is the primary defense against midair collisions.

General Right-of-Way Hierarchy

When aircraft of different categories converge, right-of-way priority is determined by maneuverability. The general order of precedence (from highest priority to lowest priority) is:

1. Aircraft in Distress: 14 CFR § 91.113(c) states an aircraft in distress has right-of-way over all other air traffic.
2. Balloons: Unpowered, limited directional control.
3. Gliders: Unpowered aircraft requiring right-of-way over engine-driven aircraft.
4. Airships: Lighter-than-air powered aircraft.
5. Powered Aircraft / Rotorcraft / Light-Sport / Powered Parachutes: Engine-driven aircraft yield to unpowered aircraft.

Special Rule: An aircraft towing or refueling another aircraft has right-of-way over all other engine-driven aircraft.

Specific Flight Operations & Converging Situations

• Converging at Same Altitude (14 CFR 91.113(d)): When aircraft of the same category converge at approximately the same altitude (except head-on or overtaking), the aircraft to the other's right has the right-of-way. (For example, if Airplane A sees Airplane B on its right, Airplane A must yield to Airplane B).
• Head-On Approaching (14 CFR 91.113(e)): When two aircraft are approaching head-on, or nearly so, each pilot shall alter course to the right.
• Overtaking (14 CFR 91.113(f)): An aircraft being overtaken has the right-of-way. The overtaking aircraft must alter course to the right to pass well clear.
• Landing Approach (14 CFR 91.113(g)): Aircraft on final approach to land, or while landing, have right-of-way over other aircraft in flight or on the ground. When two or more aircraft are approaching an airport to land, the aircraft at the lower altitude has the right-of-way, but pilots must not take advantage of this rule to cut in front of another aircraft.

Minimum Safe Altitudes (14 CFR 91.119)

Except when necessary for takeoff or landing, 14 CFR § 91.119 dictates minimum safe altitudes for aircraft operations across all regions:

1. Anywhere (14 CFR 91.119(a))

An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.

2. Congested Areas (14 CFR 91.119(b))

Over any congested area of a city, town, or settlement, or over any open-air assembly of persons:

• Vertical Clearance: At least 1,000 feet above the highest obstacle.
• Horizontal Clearance: Within a 2,000-foot horizontal radius of the aircraft.

3. Non-Congested Areas (14 CFR 91.119(c))

Over areas other than congested areas:

• General Requirement: An altitude of 500 feet above the surface.
• Open Water / Sparsely Populated: May not be operated closer than 500 feet to any person, vessel, vehicle, or structure.

VFR Fuel Reserves (14 CFR 91.151)

Proper fuel management is vital to preventing fuel exhaustion accidents. Under 14 CFR § 91.151(a), no person may begin a flight in an airplane under VFR conditions unless there is enough fuel to fly to the first point of intended landing and, assuming normal cruising speed:

• Day VFR Requirement: Fly for at least 30 minutes after reaching the destination.
• Night VFR Requirement: Fly for at least 45 minutes after reaching the destination.

Note for Sport Pilots: Because sport pilots are restricted to day VFR operations (unless specifically qualified and holding night privileges with appropriate aircraft equipment), day fuel reserve planning requires a minimum of destination fuel + 30 minutes at normal cruise speed.

Aircraft Maintenance & Inspection Requirements (14 CFR 91.409 & 91.413)

Under 14 CFR § 91.403(a), the owner or operator of an aircraft is primarily responsible for maintaining that aircraft in an airworthy condition. To ensure structural and systems integrity, Part 91 mandates specific inspection intervals:

1. Annual Inspection (14 CFR 91.409(a))

• Interval: Required within the preceding 12 calendar months.
• Expiration: Expires on the last day of the 12th calendar month following the month of the last inspection (e.g., an annual completed on June 10, 2025 expires on June 30, 2026).
• Sign-off Authority: Must be performed and signed off by an Airframe & Powerplant (A&P) mechanic holding an Inspection Authorization (IA).

2. 100-Hour Inspection (14 CFR 91.409(b))

• Applicability: Mandatory for aircraft carrying any person (other than a crewmember) for hire, or providing flight instruction for hire.
• Sign-off Authority: May be performed by a licensed A&P mechanic (IA not required).
• 10-Hour Overrun Provision: The 100-hour limit may be exceeded by up to 10 hours if necessary to reach an inspection station. However, those excess hours must be included when computing the next 100 hours of time in service.

3. Transponder & Avionics Inspections

• Transponder (14 CFR 91.413): Tested and inspected every 24 calendar months.
• Altimeter & Pitot-Static (14 CFR 91.411): Tested and inspected every 24 calendar months (for IFR operations).
• Emergency Locator Transmitter (ELT) (14 CFR 91.207): Inspected every 12 calendar months. ELT batteries must be replaced or recharged when the transmitter has been in use for more than 1 cumulative hour, or when 50 percent of their useful life has expired.

Collision Avoidance and Wake Turbulence (§ 61.309(f))

Safe and efficient operation includes see-and-avoid discipline and wake-turbulence avoidance.

Visual Scanning

• Use a series of short, regularly spaced eye movements across 10-degree sectors rather than staring at one point.
• Most midair risk occurs near airports in the traffic pattern and on converging VFR routes.
• Clear both left and right before every turn; verbalize “clear left/right” as a habit.

Wake Turbulence Characteristics

Large/heavy aircraft generate wingtip vortices that sink and drift with the wind.

• Vortices sink at several hundred feet per minute and level off about 1,000 feet below the generating aircraft’s flight path in calm air (rules of thumb used in training).
• Light quartering tailwinds can keep vortices on the runway longer than headwinds.
• Helicopters can produce strong downwash and trailing vortices—avoid flying through the rotor wash of a hovering or departing helicopter.

Avoidance Techniques

• Landing behind a heavy: stay above the heavy’s flight path and land beyond its touchdown point.
• Taking off behind a heavy: rotate prior to the heavy’s rotation point and climb above its climb path, or wait 2–3 minutes as appropriate for the scenario.
• Crossing behind a heavy en route: pass well above its altitude if practicable; avoid the area about 1,000 feet below and behind.

Wake questions frequently pair with right-of-way: even when you have right-of-way, you must still see and avoid, and you must not fly into another aircraft’s vortices.