Why do aircraft sometimes totally change their direction of travel?

Question

I have noticed that in the last few years many aircraft appear to change their direction of travel quite sharply, sometimes 30 or 40 degrees, but I have seen changes of direction of up to an amazing 90 degrees. Surely the pilot cant be lost, nor suddenly have a change of heart over the destination. I have noticed this particularly over the skies of North West England. I know there are 4 airports within 50 miles of here, but I dont think they are rreally changing destination airport. Surely the quickest way in the air is to go in a straight line.

Answer 1

It's all got to do with no-fly zones, how many planes are in the air and where they are, wind direction etc. Sometimes you'll have to go past the airport turn around and come back to it from another direction simply because of the way the wind is blowing. Plus it's nothing to do with the pilots they just go where air traffic control tell them to go.

Answer 2

two possible reasons for the SUDDEN change.

1) crosswinds or storms ahead... there is an abnormality of whether conditions quite recently. storms can appear instantly, and disappear just as fast. scary thing is, there is also an increase in their strength :(

2) sudden need to change route due to "overflooding" of flights in the same area... one would believe that the air traffic controllers have all the air routes planned out. but the major increase of flights over the couple of years have put alot of stress on our air traffic. furthermore, air traffic controllers from different airports do not keep in constant contact with each other all the time. hence, sometimes, there comes the confusion.

and yeah, i agree with the others. reasons like airspace that they suddenly cannot enter and, they have to stay in the air abit longer because alot more airplanes are landing too.

but im not criticising air traffic controllers. in fact, i think they do a great job everyday to make sure people reach their destinations safely. same with the pilots :)

Answer 3

There are many explanations to this.
1) The plane can be turning to avoid collision with other aircrafts.
2) An area can be prohibbited to fly through.
3) The aircraft can be on its final approach or decending and turning to its course.

The best way to find out is if you can see the tail and what company it says. Then you can go to that airline's website and check where the plane was going. Where i live, there are more than 5 airports within 50 miles. So if I see one, i go on a flight tracking sight and then type in what company it says and then it'll tell you all the airports that this company is going to. Try www.flightaware.com- this tells you all that companys planes that passed.

I hoped this helped!

Answer 4

As an air traffic controller there are times we have to give aircraft 'Avoiding Action' which is a turn to keep lateral seperaton between aircraft of 5 miles so if a radar return appears on the screen and we need to avoid it we'll give it an avoiding action turn which could be any amount of degrees which could explain the sharp turns. As soon as we give a pilot the turn they have to turn as quickly as is safely possible. Hope this helps

Answer 5

Aircraft follow flight plans and fly to navigation beacons called VOR stations, rather like a dot-to-dot as well as air traffic control. Most of the restricted airspace is actually reserved for airline traffic and planes aren't avoiding this. Most flights have specific routes out and a lot of flights will use these same routes and navigate to the same vor beacons eg for transatlantic routes. A common example of this is for example an aircraft flying from london may first fly north up the country to the Pole Hill VOR before making a left turn over that beacon

Answer 6

skyes are controlled by (air traffic control) "ATC" which defines "air ways" roads in the sky that pilots have to stick to, airways sometimes are not completely straight between on point to another to avoid "retricted areas" and "prohibited areas" or the no fly zones, so while you may think that the shortest distance between 2 points is the straight one, pilots have to take turns to avoid military training zones, clasified zones, even the airspace of a non friendly country.

Answer 7

Civil aircraft have to follow set routes through the air called Airways. You can get charts of these from your local flying club or good reference library.
These routes are (very roughly) analogous to motorways in that strict directional and separation rules are apllied to planes in them. They operate under strict Air Traffic Control (ATC) and aircraft are under radar monitoring at all times - so they're not lost.
Sometimes ATC will instruct an aeroplane to deviate from a straight line so that it can avoid another flight (they have to be at least 5 nautical miles apart horizantally) or some bumpy meteorological event that you may not see from the ground.

When an aircraft wants to use a particular airfield it must follow the airway until it gets to the airfield's "Terminal Manouvering Area (TMA)" which is (Very Very loosely) analogous to a combined exit of several motorways, but in 3 dimensions. The TMA for a large airport may itself be quite a big area.

In the TMA it must follow ATC instructions to avoid other aircraft which may be using a nearby airfield and take account of wind direction (which may be different from what you experience on the ground), also it must avoid noise sensitve areas (so it flys around them) and finally align itself to the landing runway - which it does about 5 miles from touchdown.

This is not a course in air traffic control but I hope it helps.

Answer 8

This is because an hour or so, or within radar range of the
control tower, the captain is given a course to fly by the
control tower for reasons of traffic etc. and sometimes
when its really busy the aircraft makes a 360 deg. turn. You
may safely say that the course is set by the control tower and
not by the Captain.

Answer 9

They are directed by air-traffic controllers along a specific route, they need to align the plane to approach the airport from a specific direction, while avoiding the paths of other aircraft.

Answer 10

They have to wait, to change direction, until they get to the junction. Seriously, there are "highways" in the sky, and the pilots have to go from one "way point" to the next before a change of direction. What you have seen is the arrival at a waypoint and that change.