Night Operations
PHAK Ch 17 • Vision, Lighting, Illusions, Currency
Night Flying Safety
Night VFR accident rates run far higher than day VFR. Allow 30 minutes for dark adaptation, trust instruments over visual cues, and always use VASI/PAPI when available.
Key Takeaways
- Full dark adaptation takes 30+ minutes; one bright flash can reset it.
- Rods (peripheral) are most sensitive in low light — use off-center viewing 10-15° away.
- Hypoxia affects night vision above 5,000 ft — consider supplemental O2 earlier.
- Smoking, carbon monoxide, fatigue, and Vitamin A deficiency all degrade night vision.
Night Vision Physiology
PHAK Chapter 17Dark Adaptation
- Takes 30+ minutes for full night vision adaptation
- Rods (peripheral vision) are most sensitive in low light
- Cones (central vision) require more light - use off-center viewing
- Avoid bright lights during adaptation - use red cockpit lighting
- One bright flash can reset adaptation process
Scanning Techniques
- Off-Center Viewing: Look 10-15° away from object to use rods
- Scan slowly - rapid eye movement reduces night vision effectiveness
- Use peripheral vision to detect movement and lights
- Focus on instruments more frequently than day flight
- Avoid fixating on single light source
AIM 8-1-6
Factors Affecting Night Vision
- Hypoxia: Vision affected above 5,000 ft at night - consider O2 earlier
- Carbon Monoxide: Even small amounts impair night vision
- Smoking: Significantly reduces night vision (equivalent to 5,000-8,000 ft)
- Fatigue: Decreases visual acuity and adaptation speed
- Vitamin A deficiency: Impairs rod function
- Bright sunlight exposure: Can delay dark adaptation
DPE Tip
Use a red flashlight for cockpit tasks to preserve night vision. If you must use white light, close one eye to preserve adaptation in that eye.
Key Takeaways
- A white-green rotating beacon = civilian land airport; a daytime beacon means weather below VFR minimums.
- VASI/PAPI on glide path = "red over white, you're alright"; red over red, you're dead.
- PCL: 7 clicks in 5 sec = highest intensity, 5 = medium, 3 = lowest, on the CTAF frequency.
- Runway edge lights are white (amber the last 2,000 ft); taxiway edge lights are blue, centerline green.
Airport Beacons
AIM 2-1-8| Beacon Color | Meaning |
|---|---|
| White-Green | Civilian land airport |
| White-Yellow | Water airport (seaplane base) |
| Green-Yellow-White | Heliport |
| White-White-Green | Military airport |
| Beacon ON during day | Weather below VFR minimums (Class B/C/D) |
Visual Glideslope Indicators
AIM 2-1-2VASI (2-bar)
- Red over Red = too low, Red over White = on glide path, White over White = too high
PAPI
- 4 lights: 4 white = high, 3W/1R = slightly high, 2W/2R = on path, 1W/3R = slightly low, 4 red = low
Tri-Color VASI
- Amber = high, Green = on path, Red = low
Memory Aid
- "Red over White, you're alright. Red over Red, you're dead."
Pilot-Controlled Lighting (PCL)
AIM 2-1-8| Clicks | Result |
|---|---|
| 7 clicks in 5 sec | Highest intensity |
| 5 clicks in 5 sec | Medium intensity |
| 3 clicks in 5 sec | Lowest intensity |
- Key mic on CTAF frequency (check Chart Supplement)
- Lights typically stay on for 15 minutes
- Re-key as needed during approach
- Works for runway, taxiway, and approach lights
Runway Lighting
AIM 2-1-4| Light | Description |
|---|---|
| HIRL/MIRL/LIRL | High/Medium/Low Intensity Runway Lights - white, yellow last 2,000 ft |
| REIL | Runway End Identifier Lights - flashing white at threshold |
| Threshold Lights | Green from approach side, red from runway side |
| End Lights | Red from runway side |
| Centerline Lights | White, alternating red/white last 3,000 ft, red last 1,000 ft |
| TDZ | Touchdown Zone - white bars on each side |
Taxiway Lighting
AIM 2-1-10| Light | Description |
|---|---|
| Taxiway Edge | Blue omnidirectional lights |
| Taxiway Centerline | Green lights |
| Clearance Bar | Yellow lights at holding positions |
| Stop Bar | Red lights - DO NOT CROSS unless cleared |
| Runway Guard Lights | Flashing yellow - elevated or in-pavement |
Key Takeaways
- Black hole approach over featureless terrain tempts a too-low approach — use VASI/PAPI and the altimeter.
- Autokinesis: a stationary light appears to move when stared at — avoid fixating, maintain a scan.
- False horizons and runway width/slope illusions distort attitude and approach — trust instruments.
- Somatogravic illusion on takeoff feels like pitch-up — don't push the nose down; reference the attitude indicator.
Night Flight Illusions
PHAK Chapter 17Visual illusions that can lead to spatial disorientation.
Black Hole Approach
Featureless terrain (water, dark areas) with only runway lights visible.
Danger: Tempts you to fly too low — no visual references to judge height.
Prevention: Use VASI/PAPI, monitor the altimeter, fly standard pattern altitude.
Autokinesis
A stationary light appears to move after you stare at it for several seconds.
Danger: Can cause disorientation or incorrect control inputs.
Prevention: Don't fixate on single lights; keep your instrument scan moving.
AIM 8-1-5
False Horizon
Sloping clouds, ground lights, or stars mistaken for the horizon.
Danger: Can lead to unusual attitudes or spatial disorientation.
Prevention: Trust instruments; cross-check the attitude indicator frequently.
Runway Width Illusion
A narrow runway looks farther away; a wide one looks closer.
Danger: You may fly too high (narrow) or too low (wide).
Prevention: Use VASI/PAPI, know the runway dimensions, hold pattern altitude.
Rain on Windscreen
Refraction through rain makes lights appear lower than they are.
Danger: Tempts a higher approach than necessary.
Prevention: Use VASI/PAPI; trust instruments over visual cues.
Bright Runway Lights
Bright lights look closer than dim lights at the same distance.
Danger: You may misjudge distance to the airport.
Prevention: Cross-check with instruments and VASI/PAPI.
AIM 8-1-5
Somatogravic Illusion (vestibular)
A vestibular (inner-ear) illusion — rapid acceleration (e.g., takeoff) feels like pitching up, even when attitude is level.
Danger: You may push the nose down in response — especially deadly on a night takeoff over dark terrain with no horizon.
Prevention: Trust instruments on takeoff; hold pitch on the attitude indicator until a visible horizon returns.
Key Takeaways
- Night currency (§61.57): 3 takeoffs and landings to a full stop within the preceding 90 days to carry passengers.
- Currency window: 1 hour after sunset to 1 hour before sunrise, same category and class.
- Required night equipment is FLAPS: Fuses, Landing light (for hire), Anti-collision, Position lights, Source of electricity.
- Night for logging is end of evening to beginning of morning civil twilight; position lights run sunset to sunrise.
Night Currency (14 CFR §61.57)
- 3 takeoffs and landings to a full stop
- Within preceding 90 days
- In same category and class of aircraft
- During the period 1 hour after sunset to 1 hour before sunrise
- Required to carry passengers at night
Night — three different time windows (don't conflate)
- Logging night time (§1.1): end of evening civil twilight to beginning of morning civil twilight
- Night-landing currency (§61.57): the 3 takeoffs/landings must fall 1 hour after sunset to 1 hour before sunrise
- Position & anti-collision lights (§91.209): sunset to sunrise
Required Equipment (14 CFR §91.205)
- Position lights (nav lights) - red left, green right, white aft
- Anti-collision lights (beacon/strobes)
- Landing light (if for hire)
- Adequate electrical source
- Spare fuses (if aircraft uses fuses)
Required EquipmentFLAPS
- FFuses
- LLanding light
- AAnti-collision
- PPosition lights
- SSource of electricity
Key Takeaways
- Verify all position, landing, taxi, and anti-collision lights plus panel lighting before night flight.
- Carry a flashlight (red lens preferred) with fresh batteries, plus a backup.
- Allow 30 minutes for dark adaptation; use red cockpit lighting and avoid bright white lights.
- Plan routes over lighted areas, note moon phase, and have alternates with runway lighting.
Aircraft Checklist
- All position lights functional and visible
- Landing and taxi lights operational
- Anti-collision lights working
- Instrument and panel lights functional
- Flashlight with fresh batteries (red lens preferred)
- Backup flashlight
Pilot Checklist
- Allow 30 minutes for dark adaptation before flight
- Avoid bright white lights before/during flight
- Use red cockpit lighting when possible
- Get adequate rest - fatigue impairs night vision
- Carry charts with night-readable markings
- Review emergency procedures
Planning Checklist
- Check for TFRs and NOTAMs (lighting outages)
- Verify PCL frequency and operation
- Plan route over lighted areas when possible
- Know moon phase and available ambient light
- Have alternate airports with runway lighting
- File flight plan for added safety
DPE Tip
Night oral question you'll get: "What does PAPI show you when you're on glidepath?" Two red, two white. All white means high, all red means dangerously low. The memory aid "red over white, you're alright" works for both VASI and PAPI.
Ask Kit
Scenario to rehearse:
“I'm planning a night cross-country. Walk me through the night currency requirements, required equipment beyond day VFR, how I should set up cockpit lighting, and what visual illusions I need to brief before departing.”
Training aid only — verify all data against your POH and current FAA publications.