Landing a plane is a continuous learning cycle. Every landing is a new lesson. It’s no simple task during the day, let alone at night. So, how do pilots land at night when visibility is low?
When visibility is limited, pilots rely on a mix of instruments, training, and teamwork to ensure a safe landing.
Night Landings vs. Day Landings: What’s the Difference?
Given a CAVOK day (High visibility and no clouds – Clear day basically) with calm winds, the daylight would provide pilots with natural visual references; you can clearly see the runway and its environment from far away, that’s why as pilots, you can even ask to do a visual approach. Most airlines prohibit their flight crew from conducting visual approaches at night.
On a clear day with high visibility (referred to as CAVOK – ceiling and visibility OK), the daylight provides pilots with natural visual references; the runway and its surroundings are visible from far away. That’s why as pilots, you can even ask to do a visual approach, an approach and landing relying heavily on external visual cues.
In contrast to the day, most airlines prohibit their flight crew from conducting visual approaches at night.
A visual approach is an ATC authorization for an aircraft on an IFR flight plan to proceed visually and clear of clouds to the airport of intended landing. A visual approach is not a standard instrument approach procedure and has no missed approach segment. (FAA)
At night, even under CAVOK conditions, visual cues are significantly reduced. For example, if the runway and surrounding features are visible from 10 km during the day, this distance may shrink to as little as 3 to 1 km at night. The runway becomes more of a silhouette, illuminated primarily by its lighting system.
Night landings demand extra vigilance and preparation compared to day landings under the same conditions at the same airport.
While some day landings can be challenging, we’ll focus here on the unique aspects of night landings.
During the day, pilots may rely on a mixture of 50% visual cues and 50% instruments. However, at night, this shifts to around 20% visual cues and 80% instruments. Instruments effectively become the pilots’ “eyes” at night.
Planning the Night Approach:
As with every landing, it doesn’t start on the final approach but it starts way before.
Pilots gather weather information, airport and approach data, and assess potential risks and hazards at the destination. This is followed by an approach briefing, which typically covers:
- Weather (ATIS)
- A/C status (MEL)
- NOTAMs
- STAR and arrival route
- Type of approach and approach procedure
- Landing data (approach speeds)
- Go-Around Procedure
- Post-landing taxi route
- Threats and hazards for a night landing.
- Specific considerations for night landings include:
- Runway lighting system in detail,
- Runway width and surroundings;
- Potential illusions.
- Specific considerations for night landings include:
Also, as part of preparing for the descent and approach, pilots often dim the cockpit lights 30 to 45 minutes before landing to help their eyes adjust to low light. This process, called dark adaptation, usually takes about 30 to 45 minutes.
It is good airmanship to avoid bright lights about 30 minutes prior to a night flight. It is also advisable to turn up cockpit lights when approaching a weather pattern which might produce the possibility of lightning. (CAE Oxford Air Law manual)
Instrument Landing System (ILS)
The ILS is the backbone of many landings. It’s a calibrated ground-based radio navigation system that provides both lateral (localizer) and vertical (glideslope) guidance.
For a night landing, pilots capture the ILS signals and then track & fly according to the guidance using the instruments on board the aircraft. Usually, the first part of the ILS is flown on autopilot and then the pilot assumes manual control, depending on airline procedures and pilot preferences.
This system helps by guiding the pilot to fly the aircraft on a calculated stable descent path using solely the instruments and no visual cues which is much needed for night landings.
Runway Lights and Approach Lighting Systems
Runway lighting is crucial for pilots landing at night, providing orientation and depth perception. Here’s a quick breakdown of what pilots look for:
- PAPI (Precision Approach Path Indicator): A set of four lights at the runway’s side indicating if the plane is too high or low.
- An alternative system is the VASI (Visual Approach Slope Indicator), which does the same job, just a different installation.
- Runway Lead-in Lights: Groups of flashing white lights that flash in sequence towards the runway.
- Runway Edge Lights: Parallel lights along the runway length.
- Runway Centerline Lights: Outline the runway centerline. They help during final alignment. They are white lights at first which turn into alternate white and red lights and then within the last 300m (1000ft) of the runway, they turn into only red lights to signal that you are approaching the end of the runway (So you better be at low speed).
- Runway Touchdown Zone Lights or Runway Threshold Identification Lights: They provide a visual cue for where to land.
Challenges and Illusions Unique to Night Landings:
Night landings are special and pose a few unique challenges, particularly related to visual illusions, some of the main ones are:
- The Black Hole Effect (The Kraft Illusion): The black hole effect involves aircraft approaching to land at night in dark skies, particularly with no starlight or moonlight. The worst affected are approaches over water, jungle, or desert, where the only lights visible are distant runway or aerodrome lights. This absence of visual cues leads to an illusion that the aircraft is too high. As a result, the approach path may be flown at too shallow of an angle — Pilots may feel they’re too high and tend to descend too quickly.
- Runway Width Illusion: A wider-than-usual runway can make pilots feel lower or closer to the runway than they are, while a narrower runway has the opposite effect.
- Runway Lighting Illusion: If the runway is dimly lit, the pilot might feel farther away than they are and the opposite is true.
Do pilots use Autoland during a night landing?
Autoland is not primarily used during your typical night landing. If anything it’s not used even during your non-typical night landing. That’s not how pilots land at night.
Autoland is used strictly when visibility is extremely low, weather permits, aircraft is capable and the airport is designed for an autoland.
So, no, not really. Pilots land manually during the night unless extreme visibility conditions are present then autoland can be considered if the above factors are within limits.
Conclusion – How do pilots land at night?
Night landings require a careful blend of instrument precision and pilot expertise. As with any landing, they demand careful planning and a systematic approach to ensure a safe arrival.
