NVFR Training

[Tinstaafl]

Do a search on these forum for 'NVFR' or 'Night VFR' and similar. You'l find a wealth of information.

Here's my NVFR training in a nutshell, copied from an older thread:

Night VFR – Some differences

Some of these points are fairly general, others specific to Australia eg the LSALT rule allowing immediate descent under certain circumstances, navaid rules.

Some may be different to what your instructor & school teaches, in which case your school's procedures should take priority.


Flight Preparation

Pilot:

Physiological limitations

Vision:
· Takes around 30 minutes for vision to adjust. Far longer if prior daytime exposure to very bright lighting eg beach, over water, snow
· Avoid bright sunlight during the day
· Peripheral vision is more sensitive in dim light so avoid looking directly at objects to see them. Better to look slightly to the side of the expected position

Sense of balance ie inner ear:
· With minimal, or no, visual reference (the natural horizon, ground etc) the human animal is not capable of determining the difference between acceleration and attitude
· Acceleration is easily and incorrectly confused for an attitude change eg forward acceleration interpreted as a pitch up
· Has a ‘minimum threshold’ for perception so any motion below that threshold is not recognised

Psychological:
· Diurnal cycle of human activity has a peak during the day but a low point around 3 or 4 am.
· May already have experienced a full day of activity prior to the flight commencing. Fatigue effects may be more problematic

Equipment:

General
· Where possible make use of the daylight to do pre-flight, refuel, move aircraft to a suitably uncongested parking area
· Avoid covering charts with contact. Reflected cockpit lighting can interfere with reading the chart
· Avoid using red or green ink or pencil. Under red cockpit lighting these colours tend to become invisible

Lighting

Additional lighting required
· Crew – torches. NB A torch held to shine through the fuel sample cup from the side is effective for seeing any water droplets.
· Aircraft - cockpit lighting (2 sources), landing lights, beacon & navigation lights, pilot & passenger compartment lights. Can check post lights during daylight by putting your finger under the beam
· Aerodrome – runway lighting, wind indicator lighting, obstruction lighting, 2 types of taxiway lights (blue sideline, green centreline), holding points

Instruments

In addition to Airspeed Indicator, Altimeter, Compass & timepiece, NVFR requires
· Attitude Indicator
· Directional Indicator
· Turn Coordinator
· Radio navigation equipment eg NDB or VOR (is DME only acceptable?). Of course this means the ground station is also necessary

Planning:

Take-off & Departure

· Consider obstacles in the circuit area & necessity to climb to LSALT (see en-route) prior to leaving the circuit area.
· Additional time & fuel will be necessary during this climb prior to departure

En-route

· LSALT required to be calculated for all route sectors (1000’ within 10nm). consider subdividing the enroute section(s) with fixes/pinpoints to allow different LSALTs to facillitate departure & arrival.
· Weather forecast needs to be very good due difficulty to see & avoid cloud.
· What navigation aids are you qualified to use & are they available? Must have at least one eg NDB

Arrival & Landing

· Plan to descend while circling within the circling area of the AD. Can reduce the height to descend by planning multiple sectors, each with it’s own LSALT, even on a straight leg eg BIK to YSBK has a high LSALT however a new LSALT can be applied from YSCN & again from 2RN
· More fuel & time will be required for this circling procedure, similarly to departure.
· Alternate requirements more extensive ie Wx, Aids, Lights
Note: 60 minute flight time limitation for ALTN due Aids


In Flight

Take-off & Departure

· Lack of visual reference after take-off & the necessity to rely wholly on instruments
· Propensity for somatogravic illusions during climb out. Limit Angle of Bank to achieve Rate 1 or so


En-route

· Must not fly below LSALT.
Note: can descend immediately to a new LSALT if visually (& only visually) past the critical object. ie don’t have to allow 10 nm behind A/C in this circumstance
· May only be able to determine presence of cloud by what you can’t see ie. Cloud occluding some or all of a town’s lights or that of an area of stars or the moon
· Navigation uses a combination of visual & radio navaid techniques

Visual:
· Navigate using light sources eg towns, cities, roads with traffic, sometimes bodies of water reflecting moon etc
· Estimating distance extremely difficult so may have to use patterns of light sources
· Bodies of water may be recognisable by the outline formed by town/city lights around the shore
· May be appropriate to use PAL to confirm position

Radio:
· NDB may have reduced range at night
· Must not focus on navigation instruments or aircraft control and accuracy can suffer


Arrival & Landing

· Don’t descend below LSALT outside the circuit area
· Approaches without glideslope guidance are extremely prone to errors in judgement due visual illusions. For a 1000’ circuit height, a base turn at 45° will give a top of final height of 500’. At this top of final you can determine the unique sight picture (‘perspective’) for an approach to that runway
· Consciously look at the far end of the runway as the threshold disappears under the nose otherwise you will look into the pool of light just ahead of the aircraft & fly into it.
· Use peripheral vision to perceive a descent (or otherwise) to the runway. Controlled power reduction can be used to maintain a sink onto the runway while raising the nose to apparently meet the runway end lights
Note: Height judgement is unreliable at night due lack of depth perception. Different runway widths & lengths will cause a flare at different heights with the high possibility of stalling at some height above the runway - hence using a controlled descent rate to the runway
· Be cautious about taxi speeds & exiting the runway. It is difficult to judge roll-out speeds at night & easy to try to exit the runway at too high a speed for control & safety.