*6A Night Ops - Night Preparation

Question 0

1. Name the two distinct types of light-sensitive cells located in the retina of the eye.
   (FAA-H-8083-3)

Answer 0

Rods and cones are the light-sensitive cells located in the retina.

Question 1

2. What is the function of the cones, and where are they located in the eye?
   (FAA-H-8083-3)

Answer 1

The cones are used to detect color, detail and far-away objects and are located in the center of the retina at the back of the eye. They are less sensitive to light, require higher levels of intensity to become active, and are most useful in the daylight hours.

Question 2

3. What is the function of the rods, and where are they located in the eye?
   (FAA-H-8083-3)

Answer 2

Rods are located in the back of the eye or retina. The rods function when something is seen out of the corner of the eye or peripheral vision. They detect objects, particularly those that are moving, but do not give detail or color—only shades of gray. Both the cones and the rods are used for vision during daylight. In the absence of normal light, the process of night vision is placed almost entirely on the rods.

Question 3

4. What is the average time it takes for the rods and cones to become adapted to darkness?
   (FAA-H-8083-3)

Answer 3

The cones will take approximately 5 to 10 minutes to become adjusted to darkness. Much more time—about 30 minutes—is needed for the rods to become adjusted to darkness.

Question 4

5. What should the pilot do to accommodate changing light conditions?
   (FAA-H-8083-3)

Answer 4

The pilot should allow enough time for the eyes to become adapted to the low light levels, and then should avoid exposure to bright light which could cause temporary blindness.

Question 5

6. Give several examples of illusions related to ground lighting conditions.
   (FAA-H-8083-3)

Answer 5

a. On a clear night, distant stationary lights can be mistaken for stars or other aircraft. Certain geometrical patterns of ground lights, such as a freeway, runway, approach, or even lights on a moving train can cause confusion. Dark nights tend to eliminate reference to a visual horizon.
b. A black-hole approach occurs when the landing is made from over water or non-lighted terrain where the runway lights are the only source of light. Without peripheral visual cues to help, pilots will have trouble orientating themselves relative to Earth. The runway can seem out of position (downsloping or upsloping) and in the worse case, results in landing short of the runway.
c. Night landings can be complicated by the difficulty of judging distance and the possibility of confusing approach and runway lights. For example, when a double row of approach lights joins the boundary lights of the runway, there can be confusion where the approach lights terminate and runway lights begin. Under certain conditions, approach lights can make the aircraft seem higher in a turn to final, than when its wings are level.

Question 6

7. During takeoff you suddenly feel as if the aircraft is in an excessively high nose-up attitude. What type of illusion is this?
   (AIM 8-1-5)

Answer 6

Somatogravic illusion. A rapid acceleration during takeoff can create the illusion of being in a nose up attitude. A pilot disoriented by a somatogravic illusion may respond by pushing the aircraft into a nose low, or dive attitude.

Question 7

8. When approaching a well-lit runway surrounded by a dark area with little or no features, what illusion should a pilot be alert for?
   (AIM 8-1-5)

Answer 7

Featureless terrain illusion—an absence of ground features, as when landing over water, darkened areas, and terrain made featureless by snow, can create the illusion that the aircraft is at a higher altitude than it actually is. The pilot who does not recognize this illusion will fly a lower approach.

Question 8

9. What should the pilot do to maintain good eyesight?

FAA-H-8083-3

Answer 8

Good eyesight depends upon physical condition. Fatigue, colds, vitamin deficiency, alcohol, stimulants, smoking, or medication can seriously impair vision.

Question 9

10. What can the pilot do to improve the effectiveness of vision at night?
    (FAA-H-8083-3)

Answer 9

a. Adapt the eyes to darkness prior to flight and keep them adapted. About 30 minutes is needed to adjust after exposure to a bright light.
b. If oxygen is available, use it during night flying. Significant deterioration in night vision can occur at cabin altitudes as low as 5,000 feet.
c. Close one eye when exposed to bright light to help avoid the blinding effect.
d. Do not wear sunglasses after sunset.
e. Move the eyes more slowly than in daylight.
f. Blink the eyes if they become blurred.
g. Concentrate on seeing objects.
h. Force the eyes to view off center.
i. Maintain good physical condition.
j. Avoid smoking, drinking, and using drugs that may be harmful.

Question 10

11. What equipment should the pilot have for night flight operations?
    (FAA-H-8083-3)

Answer 10

At least one reliable flashlight is recommended as standard equipment on all night flights. A D-cell size flashlight with a bulb switching mechanism that can be used to select white or red light is preferable. The white light is used while performing the preflight visual inspection, and the red light is used when performing cockpit operations. A spare set of batteries is also recommended.

Question 11

12. What other items should the pilot have on board for night flights?
    (FAA-H-8083-3)

Answer 11

Pilots should have appropriate navigational charts, including any charts adjacent to the intended route of flight on board for night flight. These charts should be mounted on a clipboard or mapboard to prevent being lost in the dark cockpit.

Question 12

13. Explain the arrangement and interpretation of the position lights on an aircraft.
    (FAA-H-8083-3)

Answer 12

A red light is located on the left wing tip, a green light is located on the right wing tip and a white light is located on the tail. If the pilot observes both a green and red light on another aircraft, then the other aircraft is generally approaching the pilot’s position. If the pilot sees only a green light, then the other aircraft is moving left to right in relation to the pilot’s position. If the pilot sees only a red light, then the aircraft is moving right to left in relation to the pilot’s position.

Question 13

14. Position lights are required to be on during what period of time?
    (14 CFR 91.209)

Answer 13

From sunset to sunrise.

Question 14

15. When an aircraft is operated in, or in close proximity to, a night operations area, what is required of an aircraft?
    (14 CFR 91.209)

Answer 14

The aircraft must:

a. be clearly illuminated,
b. have lighted position lights, or
c. be in an area which is marked by obstruction lights.

Question 15

16. Are aircraft anticollision lights required to be on during night flight operations?
    (14 CFR 91.209)

Answer 15

Yes; however, the anticollision lights need not be lighted when the pilot-in-command determines that, because of operating conditions, it would be in the interest of safety to turn the lights off.

Question 16

17. What are Runway End Identifier Lights (REIL)?

AIM 2-1-3

Answer 16

REILs are installed at many airfields to provide rapid and positive identification of the approach end of a particular runway. The system consists of a pair of synchronized flashing lights located laterally on each side of the runway threshold. REILs may be omnidirectional or unidirectional facing the approach area.

Question 17

18. Describe a Runway Edge Light System.

AIM 2-1-4

Answer 17

Runway edge lights are used to outline the edges of runways during periods of darkness or restricted visibility conditions. They are white, except on instrument runways yellow replaces white on the last 2,000 feet or half the runway length, whichever is less, to form a caution zone for landings. The lights marking the ends of the runway emit red light toward the runway to indicate the end of runway to a departing aircraft and emit green outward from the runway end to indicate the threshold to landing aircraft. These light systems are classified according to the intensity or brightness they are capable of producing. Examples are: High Intensity Runway Lights (HIRL), Medium Intensity Runway Lights (MIRL), and the Low Intensity Runway Lights (LIRL).”

Question 18

19. Describe a Runway Centerline Lighting System (RCLS).

AIM 2-1-5

Answer 18

Runway centerline lights—installed on some precision approach runways to facilitate landing under adverse visibility conditions. They are located along the runway centerline and are spaced at 50-foot intervals. When viewed from the landing threshold, the runway centerline lights are white until the last 3,000 feet of the runway. The white lights begin to alternate with red for the next 2,000 feet, and for the last 1,000 feet of the runway, all centerline lights are red.

Question 19

20. What are Touchdown Zone Lights (TDZL)?

AIM 2-1-5

Answer 19

Touchdown zone lights consist of two rows of transverse light bars disposed symmetrically about the runway centerline. The system consists of steady-burning white lights which start at 100 feet beyond the landing threshold and extend to 3,000 feet beyond the landing threshold or to the midpoint of the runway, whichever is less.

Question 20

21. Describe several different types of taxiway lighting.

AIM 2-1-10

Answer 20

a. Taxiway edge lights—outline the edges of taxiways; consist of blue lights.
b. Taxiway centerline lights—assists ground traffic in low visibility conditions; consists of steady-burning green lights.
c. Clearance bar lights—installed at holding positions on taxiways; consist of three in-pavement steady-burning yellow lights.
d. Runway guard lights—installed at taxiway/runway intersections; consists of either a pair of elevated flashing lights on either side of taxiway or in-pavement yellow lights installed across the taxiway.
e. Stop bar lights—used to confirm ATC clearance to enter or cross an active runway in low visibility conditions; consists of a row of red, unidirectional, steady-burning in-pavement lights installed across the taxiway and a pair of elevated steady burning red lights on each side.

Question 21

22. What are the different types of rotating beacons used to identify airports?
    (AIM 2-1-9)

Answer 21

White and green: Lighted land airport
Green alone: Lighted land airport
White & yellow: Lighted water airport
Yellow alone: Lighted water airport
Green, yellow & white: Lighted heliport
White (dual peaked & green): Lighted military airport
*Green alone or yellow alone is used only in connection with a white and green or white and yellow beacon display respectively.

Question 22

23. Describe several types of obstruction lighting. (AIM 2-2-3)

Answer 22

a. Aviation red obstruction lights—flashing aviation red beacons and steady burning aviation red lights during nighttime operations.
b. Medium and high intensity white obstruction lights—may be used during daytime and twilight with reduced intensity for nighttime operation. Not normally installed on structures less than 200 feet.
c. Dual lighting—a combination of flashing aviation red beacons and steady-burning aviation red lights for nighttime operations and flashing high intensity white lights for daytime operation.
d. Catenary lighting—medium and high intensity flashing white markers for high voltage transmission lines and support structures.

Question 23

24. How does a pilot determine the status of a light system at a particular airport?
    (FAA-H-8083-3)

Answer 23

The pilot needs to check the Airport/Facility Directory and any Notices to Airmen (NOTAMs) to find out about available lighting systems, light intensities and radio-controlled light system frequencies.

Question 24

25. How does a pilot activate a radio-controlled runway light system while airborne?
    (AIM 2-1-8)

Answer 24

The pilot activates radio-controlled lights by keying the microphone on a specified frequency. The following sequence can be used for typical radio controlled lighting systems:

a. On initial arrival, key the microphone seven times to turn the lights on and achieve maximum brightness.
b. If the runway lights are already on upon arrival repeat the above sequence to ensure a full 15 minutes of lighting.
c. The intensity of the lights can be adjusted by keying the microphone seven, five, or three times within 5 seconds.