Do flights ALWAYS get cancelled if there is fog or just sometimes?

Question

Does it depend on how much fog etc

Answer 1

Yes, it depends.

Answer 2

It depends on fog density at departure and arrival airport as well as on the routing. Some flights are delayed by it and others are cancelled while some can go according to schedule if fog isn't too bad.

Answer 3

ALWAYS? No, not always.

The flight will be canceled if the current weather or weather forecast indicates that fog will bring conditions below MINIMUM LANDING CRITERIA for the instrument approach to that airport. Instrument approaches are necessary to land when the weather cloudy or poor.

Runways with INSTRUMENT APPROACHES, have a minimum visibility and altitude values associated with them to keep pilots from flying into the ground. The more advanced the approach equipment at the airport, the lower the visibility criteria. Read about what they are here- http://en.wikipedia.org/wiki/Instrument_approach

Most major airports have approaches with a required visibility of 1/2 mile or a "RVR/runway visual range" of 1,800 feet (horizontal visibility down the concrete) and a "decision height" of 200 feet above the ground. Pilots can go no lower than this height without the runway or other specific lighting/markings in sight. Upon reaching the minimum altitude at a specified point on the approach, the pilot must go around without that visual contact.

For airline operations, visibility is the controlling factor. The weather can form a ceiling of 100 feet above the ground but if the visibility under it is at least 1/2 a mile, they are still legal to attempt the approach even if they are unlikely to get the runway in sight.

A select few have runways certified for what is called Catagory 3 or "CATiii" that allows equipped aircraft with specifically trained crews to use the autopilot for a zero visibility landing. Fog doesn't affect these kinds of operators but they are relatively few due to the cost invovled.

BTW, it doesn't "mess with the planes sensors" in any way as posted! That must be a BA joke on passengers.....

Answer 4

Its because of the fact they're the main service at Heathrow. No element asserting - 'And American airways cancelled 3 flights the day purely before this as a results of fog.' It provides a much extra suitable indication of the wather circumstances in the event that they are asserting BA cancelled seventy 5 flights etc

Answer 5

It's not fog in the air, It's fog on the ground that causes them to cancel flights
If the control tower cannnot see the aircraft they will cancel the flight

Answer 6

No they are not always cancelled. It depends on the radar capability of the airport in question. Big airports can land planes and despatch them in fog because they have sophisticated radar and blind landing facilities. Never would planes be allowed to take off if there was any danger.

Answer 7

It depends on how much fog there is. They are not always cancelled. Just sometimes.

Answer 8

It depends on how much fog

Answer 9

No, not always. It depends on how low the clouds are and how high. If the visibility is bad throughout, then they will cancel, but if it is burning off, then they will open it up again.

Answer 10

I'd say it's much more closer to "never" than "always" ... fog isn't that big a deal with modern-day equipment.

Answer 11

it depends
how much fog there is
if you can see the lights al the way down the runway
if all radar is working properly
and about 200 other things