VFR Flights at Night
VFR Flights at Night
Description
- Night VFR flying requires special consideration. It presents additional hazards that must be identified and assessed. Generally, such operations should only be undertaken by pilots that are certificated, current, and proficient in night flying. Even for experienced pilots, night VFR operations should only be conducted in unrestricted visibility, favorable winds, both on the surface and aloft, and no turbulence. If a night VFR flight is attempted but the weather is marginal or poor, the pilot and the aircraft should be certified and equipped to fly IFR. The most notable risk with night VFR flights is spatial disorientation that may lead to loss of control and controlled flight into terrain.
Examining accident research reports has shown that the accident rate during night VFR decreases by nearly 50% once a pilot obtains 100 hours and continues to decrease until the 1,000 hour level. The data suggest that for the first 500 hours, pilots flying VFR at night might want to establish higher personal limitations than are required by the regulations and, if applicable, apply instrument flying skills in this environment.
Specific Challenges
Specific challenges, associated with night VFR flying include the following:
- natural horizon may not be present (especially in dark night conditions), hence spatial disorientation may occur. Also, visual illusions can cause confusion. For example, cloud layers or even the northern lights can confuse a pilot and indicate a false visual horizon.
- during the approach, the judgment of height, speed, and sink rate is impaired by the scarcity of observable objects in the landing area.
- it is usually difficult to see clouds and restrictions to visibility, particularly on dark nights or under overcast. Therefore, the risk of a VFR flight inadvertently entering IMC is increased at night.
- terrain could be less recognizable as a threat. While most obstacles (e.g. buildings, wind turbines, antennae, etc. are expected to be lit at night, this does not apply to hills and mountain ridges.
- fatigue is more likely to affect the pilot in case of a night flight. While this applies to both IFR and VFR operations, the former are normally associated with commercial aviation where pilots are usually more experienced.
- visual navigation may be adversly affected. Especially during dark night, over large bodies of water or in remote areas, matching the terrain features to a map could prove difficult.
Pilot Considerations
Pilots performing night VFR flights need to consider additional aspects of the operation both during the pre-flight preparation and during the flight itself, e.g.:
- determine safe altitudes in advance by using the altitudes shown on VFR and IFR charts during preflight planning. This would help avoid terrain and obstacles.
- if the trip includes flying at night over water or unpopulated areas with the chance of losing visual reference to the horizon, the pilot must be prepared to fly IFR.
- consideration whether the flight conditions will allow a safe emergency landing
- perform preflight check of all aircraft lights, interior and exterior, and carry a flashlight
- susceptibility to visual illusions can be reduced through training and awareness and learning to rely on flight instruments
- avoid flying into clouds. Usually, the first indication of flying into restricted visibility conditions is the gradual disappearance of lights on the ground. If the lights begin to appear being surrounded by a halo or glow, caution is advised if attempting further flight in that direction as this is indicative of ground fog.
- ice detection lighting may be installed on some aircraft to determine the extent of structural icing during night flights
Regulatory Provisions
The specifics of night VFR operations described above have lead to some regulatory provisions being developed for these flights. ICAO Annex 2 stipulates that the appropriate ATS authorities may impose certain conditions on VFR flights between sunset and sunrise. It is therefore up to the states to decide what these conditions would be and consequently, the provision differ from one part of the world to another. Examples of such conditions include:
- Requirements for pilot experience or qualification
- Restricting night VFR operations to specific flights (e.g. in the vicinity of an aerodrome, HEMS, etc.)
- Different (higher) visibility minima being applicable at night
- Altitude requirements
- Mandatory flight plan filing
- Mandatory two-way communication with the appropriate ATS unit
In the EU, the requirement for night VFR flights are listed in Regulation 923/2012. When so prescribed by the competent authority (i.e. the national civil aviation authority), such flights may be permitted under the following conditions:
- if leaving the vicinity of an aerodrome, a flight plan must be submitted
- flights must establish and maintain two-way radio communication on the appropriate ATS communication channel
- the VMC visibility and distance from cloud minima apply except that:
- the ceiling must not be less than 1 500 ft (as opposed to 1000 ft otherwise)
- the reduced flight visibility provisions (i.e. reducing the visibility requirement to 1500 m under specific conditions) do not apply
- in airspace classes B, C, D, E, F and G, at and below 3000 ft AMSL or 1000 ft above terrain, whichever is the higher, the pilot must maintain continuous sight of the surface
- for mountainous area, higher VMC visibility and distance from cloud minima may be prescribed by the competent authority
