Question.....why all the banking

[teijeh]

Hello all......I'm not even sure how I found this place but here I am.

My question is, what is going on when the pilot states that they are expecting a smooth ride and the entire duration of the flight consists of changing altitude and banking all over the place? I have found that this happens most often on American Airlines or US Airways usually on 747 type planes. Do they have different SOPs for flying?? ie. no autopilot?? Although the flights are not turbulent, I spend the whole flight feeling like I'm on some long horrible drawn out roller-coaster ride.

As I type this I am laughing at my total lack of knowlege and inability to use proper terminology so please feel free to laugh as well. :hmm:

Anyways......any insight would be appreciated, I would like to avoid these type of flights but obviously if the reason is weather/traffic/whatever related it won't be possible.

[eastern wiseguy]

As an air traffic controller my reading of a "smooth ride" is one where there is little or no turbulence. Pilots often ask for "ride reports" from other crews and as such they may alter heading or level to avoid turbulence. Unfortunately aircraft and airports are not always in a the happy position to allow a straight line to be drawn between them hence the turns. As for climbing and descending ...if you dislike that try a train!:)

[GwynM]

I think it may depend where you sit in a 747. Over the wings a turbulent flight can feel stable, but right at the back (where there are only 2 seats together next to the window) any little tremor seems amplified (especially while taxiing)

[Leezyjet]

Just thought I'd point out that neither American Airlines or US Airways operate the 747 !!.

:ok:

[teijeh]

Oops....noted. 767?

Anyways, thanks for the replies. It's not the turbulence or climbing/decending, its the the instances when I am looking out the window 2 hours into a trip and suddenly the wing is no longer parallel to the ground - it feels and looks the same as after takeoff when turning towards whatever direction we should be going in.

When altering level or direction midway through a flight, what determines how quickly/severly to bank the plane? I will illustrate the entire duration of these few flights I've been on below:

\
l
/
l
\
l
/
x 3 hours

I should mention I do realize how ridiculous this topic is.

[teijeh]

Well that little schematic sure failed! :ugh:

[hardhatter]

From where to where are you flying? If you are flying through a bit of airspace which is used very much ( I have no idea where this is excatly in the States, I can imagine around Chicago or New York), the ATC will guide the aircraft through the traffic over the designated airways, which maybe could result in a lot of banking, switching from one airway to the next.

Try to see if you can find a map of airways ( help me ATC personnel or pilots, am I using the correct term?) which shows you starting point and your destination. Try taking it along during your flight (if allowed) and try to keep track during your flight. Fun to do and shows you the logic of the banking.

Hope this helps a bit?:confused:

[AdamC]

I'm not qualified to comment, but my guess is that aircraft have to join airways to the next Waypoint/VOR - Think of airways like motorways/highways, you usually cannot follow one straight road to your destination.

Departure turns are usually in the SID (Standard Instrument Departure), your guess is as good as mine as to why they are there.

[Rush2112]

I would hazard a guess that there would be times when they are 'steering' around weather to avoid turbulence, in addition to any air traffic considerations.

[Cap'n Arrr]

When an aircraft flies, it almost always does not fly in a straight line from A to B, but flies via Waypoints, sort of like in a car you dont drive through houses, you turn to follow the roads. The altitude changes can be due to ATC. A jet is more efficient at high altitude, so they try and get as high as they can. Also when arriving at the destination it is not always possible to have a constant descent, but rather the aircraft gets "stepped" down by several levels.

Hope that helps

(A smooth flight means that they arent expecting any or much turbulence, not that the plane will fly in a straight line at one alt:ok:)

[merlinxx]

Aeroplanes turn corners and go up/down stairs as well you know, otherwise they'd be called trains, boats, cars, coaches etc. Sorry these go up/down hills as well!

[teijeh]

Ahhh I seem to forget that there is more than one plane in the air while I am flying. And waypoints, this makes sense and I would love to see a map of these.....to me, the airspace is one big free-for-all but I can see how this could cause problems :ok:

The few times when I've noticed this it's been from from NC or Toronto to either Washington, Pittsburg or Newark which I would assume are busy areas.

[Pontius Navigator]

When an aircraft flies, it almost always does not fly in a straight line from A to B, but flies via Waypoints,

I was going for a fun but decided not to.

What Cap'n says is true but may I expand?

While the flight path overland may be via fixed positions on the ground and the aircraft 'beacon crawls' turning at each airways beacon waypoint this reliance is reducing where RNav rules apply. That is Area Navigation where the aircraft may rely on GPS.

On long legs and the Atlantic in particular the track may be 'straight' but straight in this context is not strictly true.

An aircraft departing London at 50 degrees North and flying over Cornwall and maintaining the 50th parallel of latitude would fly 3160 statute miles to a location north of Montreal. Throughout the flight it would fly wings level and maintain a heading of 270 degrees. This is a 'small circle' route following a line of latitude.

On the other hand it another aircraft departed London and set heading for Dublin and about 25 degrees right of the other aircraft it could eventually arrive at the same spot after flying only 2970 miles, 190 miles less, save over 20 minutes flying and a few tonnes of fuel. When it arrived it would be on a course of about 230. It would have turned through 65 degrees to reach the same point. It would have followed what is known as the 'great circle' track. The great circle is like a hoop drawn round the equator and then tilted to join any two places on the World and is the shortest line between two places.

It was not usual to fly a true great circle as the aircraft would be continually banking a small amount so a modified great circle would be flown with the aircraft crossing each 10 degree line of longitude at a whole degree of latitude. Something similar, but with tighter separation is still used, as far as I am aware, so that aircraft with different transatlantic destinations may be deconflicted. Track, as well as being shorter would also fly as much as 400 miles north of the other track.

The final variation is due, as others have said to weather, but not necessarily cloud or storms but to take advantage of the wind. Generally westbound traffic will fly to the south and eastbound to the north. The south to reduce the headwinds the north to catch the tailwinds.

Either a great circle track or a minimum time track all reduce time and fuel but involve regular changes of heading and even height.

[PAXboy]

One simple reason gfor a/c to bannk and turn is to avoid bad weather. The flight crew might advise that it's going to be a smooth flight and then ensure that it IS by manouvering around bad weather.

If you are on a flight with a map in the IFE system (the one that shows a snail-trail of the path flown) you can sometimes see the results of this:

Bank left and a short while later bank right.
Steady as you go for a bit
Then bank right and ... left again to get back on the orignal track thus avoiding the nasty clouds that have bumps in them.