Night Operations

Description: As we progress in our flying careers, we will have to be ready to fly at any time of the day including night time. 

Objective:  For the student to exhibit knowledge relating to the elements of night flight, including physiology, lighting, airport operations, navigation, FARs

 

Reference: PHAK 

 

Elements:

 

How we see 

 

1. How vision works 

1. Light enters the cornea at the front of the eyeball, travels through the lens, and falls on the retina 

2. The retina contains light-sensitive cells that convert light energy into electrical impulses that travel through the brain. 

3. The brain interprets the electrical signals to form images. 

2. Two kinds of light-sensitive cells 

1. Cones

1. Responsible for all color vision.

2. Concentrated towards the center of the field of vision at the back of the retina. 

3. The fovea is a small pit where many cones are located and this is where most looking occurs. 

2. Rods

1. Better to detect movement and provide vision in dim light. 

2. Unable to discern color but are very sensitive in low light levels. 

3. Located away from the fovea. 

 

1. Factors related to night vision 

 

1. Rods are 10,000 times more sensitive to light than the cones, making them the primary receptors for night vision.

2. Rods are responsible for peripheral vision and due to the cones located in the center of the field of vision, there will be a blind spot in the center.  

3. To see an object clearly at night, the pilot must use off-center viewing to expose the rods to the image. 

1. Look 5 degrees to 10 degrees off-center of the object. 

4. Rods take like 30 minutes to fully adapt to darkness. 

1. Bright lights can destroy night vision 

2. Also, smoking reduces the amount of oxygen your body gets, and thus should also be avoided i. it can be equivalent to adding 5000 ft in altitude ii. fatigue, colds, alcohol, etc. affect night vision

5. To scan at night, pilots must look from right to left or the opposite.

1. Begin scanning at the greatest distance an object can be perceived (top) and move inward toward the position of the aircraft (bottom). 

2. For each stop, an area 30 degree wide should be scanned. 

3. The duration of each stop is based on the degree of detail that required but no longer than 2-3 seconds. 

4. Off-center viewing but do not view longer than 2-3 seconds as images will disappear. 

6. Other good habits

1. close one eye when exposed to bright light to reduce the effects of blinding.

2. move the eyes more slowly at night 

3. blink the eyes if they become blurry 

4.  concentrate on seeing objects

5.  force the eyes to view off-center

 

2. Disorientation and night optical illusions 

1. Autokinesis - caused by staring at a single point of light against a dark background for more than a few seconds. After a few moments, the light appears to move on its own. 

1. Focus the eyes on objects at varying distances, avoid fixation, use good visual scanning skills,, vary the light intensity to prevent it. 

2. False horizon - Happens natural horizon is obscured or not readily apparent. 

1. Generated by confusing bright stars and city lights or flying toward the shore or an ocean. 

3. Reversible perspective illusion - an aircraft may appear to be moving away from a second plane when in fact it is actually approaching the second plane. 

1. Pilots should observe airplane lights and their position relative to the horizon. 

4. Size distance illusion - Viewing a light that is increasing or decreasing their brightness. 

1. Pilots may interpret the lights as approaching or retreating. 

5. Fascination - Pilots ignore orientation cues and fix their attention on a goal or an object. 

6. Flicker vertigo - a light flickering between 4-20 cycle second can produce nausea, vomiting, and vertigo. 

7. Landing illusions 

1. above featureless terrain at night, there is a tendency to fly a steeper approach. 

2. Bright lights, steep surrounding terrain, and a wide runway can produce the illusion of being too low with a tendency to fly a higher than normal approach. 

3. The bright runway or approach lighting systems can create the illusion that the aircraft is low. 

8. When flying in pitch black, it may be hard to fly VFR as you may have trouble finding the horizon or there is a lack of visual references. 

1. Use your instruments 

9. If you have to look around the cockpit, try to do so in non-maneuvering flight with minimal head movements

10. If you become disoriented, reduce workload as much as possible and concentrate on flying the aircraft straight and level with reference to the HUD

11. You may need to execute unusual attitude recoveries

 

3. Proper adjustment of interior lights.

1. The red light is used when performing cockpit operations. It is also recommended to have a spare set of batteries for the flashlight readily available.

1. The rods on the retina are least affected by the wavelength of red light

2. Bright enough to read and interpret

3. Not too bright to wash out dark sensitivity outside the aircraft

4. As the ambient level decreases from twilight to darkness, the intensity of the cockpit lights is reduced to a low, usable intensity level that reduces any glare or reflection off the windshield. 

5. Brief you passengers in the importance of light discipline during night flight so the pilot is not blinded and loses dark adaptation

 

4. Importance of having a flashlight with a red lens. 

1. The red light is used when performing cockpit operations.

2. The rods on the retina are least affected by the wavelength of red light

3. If a red light is used for reading an aeronautical chart/checklist, the red features will not show up very well

 

5. Night preflight inspection 

1. Preflight should be scheduled as early as possible in the flight planning sequence, preferably during daylight hours, allowing time for maintenance assistance and correction

2. On top of day VFR flight requirements, night VFR requirements are needed too. (91.205)

3.  If a night preflight is necessary, a flashlight with an unfiltered lens (white light) should be used to supplement lighting.

4. Windscreens are checked ensuring they are clean and relatively free of scratches

5. All aircraft operating between sunset and sunrise are required to have operable navigation (position) lights

6. While anti-collision lights are required for night visual flight rules (VFR) flights, they may be turned off any time they create a distraction for the pilot.

7. Strobes should be turned on

8.  It is recommended that a pilot practice locating each instrument, control, and switch, both with and without cabin lights

9. Before starting the engine, make sure all necessary equipment and supplies needed for the flight, such as charts, notepads, and flashlights, are accessible and ready for use

 

6. Engine starting procedures, including use of position and anticollision prior to start

1. Once seated in the airplane and prior to starting the engine, arrange all items and materials to be used during the flight so they will be readily available and convenient to use. 

1. Take extra caution at night to assure the propeller area is clear. 

2. Turning the rotating beacon ON, or flashing the airplane position lights serves to alert persons nearby to remain clear of the propeller. 

1. Beacon lights can either be a red beacon or white strobe lights

3. After starting the engine and when ready to taxi, turn the taxi or landing light ON alongside the position lights.

1. Position lights are red on the left and the green on the right, white on the black. 

4. When using lights, consideration should be given to not blinding other pilots. 

 

7. Taxiing and orientation on an airport 

1. Taxi slowly, particularly in congested areas. If taxi lines are painted on the ramp or taxiway, follow the lines to ensure a proper path along the route.

2. Use the checklist for the before takeoff and run-up checks and procedures. 

3. Hold or lock the brakes during the run-up and be alert for any forward movement.

4.  An instrument check should be done while taxiing to check for proper and correct operation prior to takeoff.

5. Night operations require half the speed, twice the caution

6. Perform everything with half the speed and twice the caution

7. Internal lights/displays must be as dim as possible while still being readable

 

8. Takeoff and climb out

1. The limited availability of outside visual references

2. Flight instruments should be used to a greater degree in controlling the airplane.

3. Adjust the flight deck lights to a minimum brightness that allows reading the instruments and switches but not hinder outside vision.

4. Ensuring that the final approach and runway are clear of other air traffic, 

5. Turn the landing and taxi lights ON and all lights and line the airplane up with the centerline of the runway

6. After the airplane is aligned, note the heading indicator and set to correspond to the known runway direction. 

7. Accelerate smoothly and maintain centerline during takeoff. 

8. The procedure for night takeoffs is the same as for normal daytime takeoffs except that many of the runway visual cues are not available. 

9. Adjust pitch and airspeed using visual and instrument references. 

10. Turn landing light off after departure as they can create distractions and illusions. 

 

9. In-flight orientation 

1. At night, it is difficult to see clouds and restrictions to visibility, particularly on dark nights or under overcast. 

2.  The first indication of flying into restricted visibility conditions is the gradual disappearance of lights on the ground. 

1. If the lights begin to take on an appearance of being surrounded by a halo or glow, use caution in attempting further flight in that same direction. 

3.  Under no circumstances should a VFR night flight be made during poor or marginal weather conditions unless both the pilot and aircraft are certificated and equipped for flight under instrument flight rules (IFR).

4. When crossing bodies of water, ditching can be deadly. 

5. During the night, the water blends in with the horizon. 

1. Stars reflect on the water making it hard to determine horizon also. 

6. Lighted runways, buildings, or other objects may cause illusions to the pilot when seen from different altitudes.

 

10. Importance of verifying the airplane’s attitude by reference to flight instrument 

1. Lack of visual references and horizon can disorient pilots and make the flight into an IFR condition. 

2. Make use of the instruments to make sure that you are coordinated and in the attitude you wish. 

3. Pilots are more susceptible to illusions and hypoxia at night so we need to rely on instruments sometimes. 

 

11. Night emergencies procedures 

1. Maintain positive control of the airplane and establish the best glide configuration and airspeed. Turn the airplane towards an airport or away from congested areas.

2. Check to determine the cause of the engine malfunction, such as the position of fuel selectors, magneto switch, or primer. If possible, the cause of the malfunction should be corrected immediately and the engine restarted. 

1. If you know what is wrong, go through the appropriate checklist. 

3. Announce the emergency situation to air traffic control 

4. If the condition of the nearby terrain is known and is suitable for a forced landing, turn towards an unlighted portion of the area and plan an emergency forced landing to an unlighted portion.

1. Consider an emergency landing area close to public access if possible. This may facilitate rescue or help if needed.

5. Maintain orientation with the wind to avoid a downwind landing.

6. Complete the before landing checklist, and check the landing lights for operation at altitude and turn ON insufficient time to illuminate the terrain or obstacles along the flight path.

7. After landing, turn off all switches and evacuate the airplane as quickly as possible.

 

12. Traffic pattern 

1.  it is important that the runway lights and other airport lighting be identified as early as possible

2. Make a call to ATC or CTAF to announce your position and intentions. 

3.  Fly toward the rotating beacon until the lights outlining the runway are distinguishable. 

4.  To fly a traffic pattern of proper size and direction, the runway threshold and runway-edge lights must be positively identified

1. Turn on pilot-controlled lights 

1. 7 mic clicks - high intensity 

2. 5 mic clicks - med

3. 3 mic clicks - low

2. Distance may be deceptive at night due to limited lighting
   conditions.

5.  Once the airport lights are seen, these lights should be kept in sight throughout the approach.

6. When entering the traffic pattern, always give yourself plenty of time to complete the before landing checklist.

1. Make sure landing lights are on

7. Enter on a 45-degree angle to the downwind or join midfield to a downwind. 

8. Set heading indicator to the runway heading to establish pattern legs. 

 

13. Approaches and landings with and without landing lights. 

1. Maintain the recommended airspeeds and execute the approach and landing in the same manner as during the day. 

2. A visual approach slope indicator (VASI) is an indispensable aid in establishing and maintaining a proper glide path. 

3. On the final approach and aligning the airplane midway between the two rows of runway-edge lights, note and correct for any wind drift.

4.  use pitch and power to maintain a stabilized approach.

5. Use flaps normally. 

6. Roundout and flare is the same as day but due to the dark, pilots may have a flare too high. 

1. Constant descent and approach until the landing lights reflect on the runway and tire marks on the runway can be seen clearly.

7. During landings without the use of landing lights, the round out may be started when the runway lights at the far end of the runway first appear to be rising higher than the nose of the airplane. This demands a smooth and very timely round out and requires that the pilot feels for the runway surface using power and pitch changes, as necessary, for the airplane to settle slowly to the runway. 

 

14. Go-around 

1. May be conducted but just be more cautious. 

2. If the go-around is conducted in an area of low light, make sure to use your instruments too. 

Vasi lights

PAPI lights 

 

1. Motion parallax - Apparent movement of stationary objects as viewed by an observer across the landscape.

1. Near objects look as if they are going backward relative to our direction of travel while far objects look as if they are going forward. 

2. Geometric perspective - objects have a different shape when viewed at varying distances and from different angles. 

1. Linear perspective - parallel lines such a runway lights tend to converge as the distance from the observer increases. 

2. Vertical positionings in the field - objects or terrain features farther away from the observer appear higher on the horizon than those closer to the observer. 

3. Aerial perspective -