Questions tagged [visibility]
The maximum distance at which objects can be seen.
36
questions
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vote
1answer
103 views
What is the difference between mist and haze in terms of relative humidity?
I am an aviation meteorologist and I struggle to distinguish the two of them.
36
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4answers
5k views
Why is the position of the pilots' head (eyes) so important?
From this question:
What are these Lights on Center Holm between Windows on the A320?
I learn that the pilots' eye position is important. Enough to justify an extra piece of equipment.
But why? Can't ...
2
votes
1answer
71 views
Is an area of localized reduced visibility considered to be a cloud?
If there an area containing visible moisture in an otherwise clear sky and that area of visible moisture is transparent is it considered a "thin cloud" or simply a "localized area of reduced ...
11
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1answer
2k views
What is the difference between RVR and visibility?
What is the difference between Runway Visual Range (RVR) and visibility? Looking at the definitions, both RVR and visibility tells the pilot whether they have enough visibility to land on the runway ...
-4
votes
2answers
185 views
Why are there no emergency flight rules in place to prevent IFR-certified helicopters, operating under special VFR, crashing in low visibility (IMC)? [closed]
In modern times, engineering allows humans to do everything: Drive in fast cars or trains, diving into the deep sea, and even going to space. Which is a great thing indeed.
But when it comes to ...
0
votes
1answer
267 views
Why do helicopters crash in low visibility (IMC)? [closed]
There are no known direct eyewitnesses of the crash of helicopter flight Sikorsky S-76B N72EX with 9 people on board, including Kobe Bryant. However, there are many earwitnesses who heard the ...
0
votes
2answers
109 views
With current technology, why is there still increased separation between aircraft and delays in low visibility conditions?
Since most (if not all) commercial aircraft are equipped with inertial and satellite/GPS navigation, why is increased separation between aircraft necessary? Can't controllers immediately identify the ...
6
votes
3answers
240 views
How useful is skyscrapers and high buildings lighting to get a visual reference for pilots by night? (not obstruction lights, just general lights)
I would like to know how useful is skyscrapers and high buildings lighting to get a visual reference for helicopter and small planes pilots by night in cities like New York. This is different from ...
6
votes
2answers
2k views
Why is autolanding ILS a thing, but not autotakeoffing ITS? [duplicate]
In this answer to the question of why zero-visibility landings are legal and routine but not zero-visibility takeoffs, the poster makes the following point:
When an aircraft lands in near zero ...
2
votes
1answer
376 views
What are the consequences of turboclair system on restriction due to turbulences?
A turboclair system basically consisted of jet engines used to warm the air around the runway and dissipate the fog. I understand that better visibility due to less fog allows less-well-equipped ...
1
vote
1answer
684 views
Why can't pilots manually fly a low visibility approach instead of using auto land?
Pilots have instruments that help them land. But in low visibility they are required to use auto land. Why can't they rely on their instruments at those times?
1
vote
0answers
40 views
From how far away are the navigation lights of a large airliner typically visible? [duplicate]
I live about 22 miles away from one international airport in the UK, and just over 30 miles away from another.
When I spot aircraft lights at night and check for corresponding aircraft on ...
3
votes
3answers
421 views
Why is there no instrument taxi system for low-visibility operations?
In one of the comments on this answer regarding ILS category IIIc operations (or, rather, the lack thereof), it's mentioned that
There is no [radio] guidance for taxiing except the pilot's vision.
...
6
votes
1answer
165 views
How good is the ground visibility by a moonless night In the Grand Canyon?
My night flying experience is limited to light-polluted coastal southern California.
When flying over low-population countryside on a clear, moonless night, do the stars provide enough light to ...
3
votes
1answer
840 views
What is acceptable visual cue at Decision Height when performing CAT II approach?
For CAT II approach, the decision height is below 200ft but not lower than 100ft with RVR of 300m. In this case, if the aircraft is at 100ft above the ground, should the captain of that aircraft be ...
14
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7answers
4k views
Why can a plane land in zero visibility conditions but not take off in zero visibility?
After waiting hours for a flight departure delayed because of heavy fog, I wonder why planes can perform an instrument landing with no visibility, but cannot take off without a minimum visibility.
6
votes
1answer
424 views
What does METAR show when actual RVR is below the reporting minimum?
RVR is measured between 50m and 1500m (ICAO). When the actual RVR is below 50m, what does METAR show?
4
votes
1answer
593 views
Can the touchdown RVR be replaced by the midpoint or rollout RVR?
When there are three RVRs equipments in place and an ILS approach chart minumum for the runway simply says "RVR 800m" without any additional notes, is the touchdown RVR the only controlling RVR? If so,...
3
votes
3answers
286 views
What constitutes “the lights delineating the runway”?
ICAO defines RVR as "The range over which the pilot of an aircraft on the centerline of a runway can see the runway surface markings or the lights delineating the runway or identifying its centerline."...
8
votes
1answer
455 views
Does the definition of visibility take object size into account?
Overall, visibility is the distance at which objects may be discerned.
Does this definition take into account the size of the objects? Obviously large objects can be seen from farther away than small ...
5
votes
1answer
4k views
What is the relationship between temperature, dew point and the formation of clouds?
What can you infer from the temperature / dew point values in this METAR?
EGJG 121630Z 09012KT 9999 SCT006 15/14 Q1015
I understand the temperature is 15 degrees and the dew point is 14, and I ...
6
votes
1answer
967 views
Do any aircraft windshields have anti-reflective coatings?
Anti-reflective coatings are used in many applications to reduce glare and prevent double images. Double images in particular are a concern because of the several layers involved in a cockpit window. ...
3
votes
5answers
2k views
Why don't aircraft (commercial and military) use reflective visor windshields?
Just like those used on an astronaut's helmet, these reflective visors can help in better visibility when facing the sun (or any bright light source). But the windshields of most aircraft (commercial ...
3
votes
0answers
4k views
Can I spot the drones watching me in the sky with naked eyes? [closed]
To quote John Oliver:
"Yemen, home to 26 million Yemeni people, and 27 million American drones."
While these numbers may be slightly exaggerated I started to ...
2
votes
1answer
281 views
Is white/brown-out effect hazardous during the landing roll out?
Landing on unpaved runways or runways covered by snow or dust causes a white/brown-out visibility restriction.
Does it disrupt the pilot's visibility during the roll out in a fixed-wing aircraft?
9
votes
1answer
461 views
What is an Enhanced Vision System?
I was reading something at work that said the company has installed an Enhanced Vision System on the aircraft.
FedEx Express added Enhanced Vision Systems to 250 aircraft, which will greatly ...
19
votes
2answers
11k views
How is the visibility at airports measured?
What tools are being used by airports to measure visibility precisely?
Do we have some kind of tools on aircraft as well for measuring visibility?
3
votes
4answers
2k views
Is there a database of airport ceilometer raw data?
I am interested in obtaining raw ceilometer data, to test some cloud/aerosol layer identification algorithms.
Is this type of data freely available or will I need to ask for it directly from the ...
7
votes
2answers
8k views
Which airports have ILS Cat IIIC?
Are there any airports with ILS working CATIIIC?
What do the charts for this procedure look like? Is there a missed approach procedure?
15
votes
3answers
4k views
Why are aircraft external lights round, not tear-drop shaped?
I saw this image of a Cessna 172's tail posted on another question and it made me wonder why the beacon light is basically a cylinder, and not a more aerodynamic, teardrop shape?
Image source
13
votes
1answer
1k views
Are zero visibility landings a possibility for the future of commercial aviation?
Airports usually close or slow down activities in fog conditions, e.g. this seems to be a significant problem in winter at Delhi airport.
Large commercial aircraft would be able to land with no ...
23
votes
8answers
44k views
How do pilots see at night if airplanes don't have front lights?
How can pilots identify threats ahead of them if they don't have front lights like cars?
4
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2answers
6k views
How can landing in zero visibility be safe?
I recognise that autoland and ILS can enable landings in zero visibility, which I presuppose in this question (e.g. in this video where touchdown happens around 5:22). Further, suppose that the fog is ...
34
votes
5answers
10k views
What happened during this foggy landing?
Several years ago, I was flying from the USA to Buenos Aires. That's a very long flight, and it was overnight for us. When I woke up it was early in the morning and we were over Argentina. I don't ...
1
vote
1answer
2k views
Are red obstacle lights near an airport required to be lit during the day?
What are the FAA Beacon Light Requirements for 80 foot tall High Mast Poles Near an Airport? Specifically, do the RED beacon lights need to be illuminated 24 hours per day? Or, do they only need to ...
7
votes
2answers
8k views
What is the definition of visibility as seen in aviation weather reports?
If you look at the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) page for Washington D.C., Reagan National Airport (KDCA), it shows hourly weather ...
