Why does it turn during take-off?

[cichlidfan]

Simple Answer?,

 

The Left Engine Spools Up Quicker than the Right?

 

So if you taxi for a minute, to get the engines caught up to each other, then it will roll straight? I don't think so.

[SkateZilla]

Im not talking about start up spooling.

 

im talking about spooling from 60% to 100% on take off roll. just a thought.

 

if i was using the TM Warthog, I'd put right Engine up more than the left to compensate until i was in the air.

 

But if it's a steady right/left veering, then it's either calibration (doubt it), Cross winds or DRAG.

 

Most of the time it's X-Wind.

Edited August 15, 2013 by SkateZilla

[Evil.Bonsai]

Could be any number of things, but you will need to control it slightly as it travels down the runway.

[roadrabbit]

Could be any number of things, but you will need to control it slightly as it travels down the runway.

 

:smartass: Spot on! As one respondent said earlier, there is a lot going on here. In the real world as each wheel rolls it will get variable friction drag from the wheel itself and the rolling resistance between wheel and runway. Therefore you will always need to control the direction of the aircraft during the take-off roll. Even driving a car you need to continually make steering corrections - see how learners 'steer' when they first start driving. After a while it becomes automatic and the corrections experienced drivers make are generally very small.

 

From some of the previous comments it would appear that some think that all you need to do is point it straight at the beginning of the t/o roll and that should be it - unfortunately this is just not so.

 

If your nosewheel light is pointing off to one side it is a safe bet that your nosewheel is pointing that way too, so start the t/o roll with the light pointing straight too.

 

Also, to counter one engine spooling up faster than the other, open up power as they do in the real world: stand the thrust levers up about 1/3 power, pause 2 to 3 seconds to let power stabilise (big jets like the B747 require longer for their engines to stabilise away from idle - up to 5 to 6 seconds, due to their inertia), then smoothly open up to full power, but DON'T slam them open - again, take about 3 seconds. This will allow the engines to spool up together. You will be surprised how much smoother and more stabilised everything becomes. :thumbup:

[Flagrum]

It could even be pebbles and dirt on the runway ... I mean, have you ever wondered why the take off accelleration is such a bumpy ride?

 

(i.e. I would not be too surprised if ED had factored in a bit randomness)

[roadrabbit]

It could even be pebbles and dirt on the runway ... I mean, have you ever wondered why the take off accelleration is such a bumpy ride?

 

(i.e. I would not be too surprised if ED had factored in a bit randomness)

 

Anyone who has been to Moscow Sheremetievo or Vnukova airports will agree about bumpy runways. Just like those modelled in DCS world the runways are constructed from rectangular blocks of concrete. These have always spoiled otherwise good landings by civil aircrew - the passengers all think that the landing wasn't so good, but its just the slightly irregular runway surface. :huh:

[Bushaman]

So does anyone else's taxi light point right, or is that just me? I don't think a bumpy runway would cause my taxi light to not be centered.

[SkateZilla]

^ there was already a discussion about this too.

[Bushaman]

SkateZilla - sorry if i missed it. But I don't think I've seen anyone addressing it when my taxi light is pointing right. It points right before i even move ie. in its starting position.

[nobrot]

An asymmetrical payload may cause some turning, but a cross-wind will have greater effect, particularly early on in the take-off. If the aircraft is properly aligned before starting the take-off roll, you can safely disengage NWS fairly quickly and maintain runway center line using rudder. If there is a cross-wind, you may need to keep some opposite rudder in during rotation.

[PFunk1606688187]

So basically the plane is supposed to turn like in the video if you don't keep making minor adjustments for the wheel?

 

I guess I kind of expected it to go straight by it self once it's been lined up. Need more practice with the pedals.

 

Are you a motorist by any chance? I don't think cars going at any speed will remain straight for without any corrections if you drove them to thier speed limit for a distance of a few miles.

 

Its something they often don't explain to people I guess, because we just know this. You drive a car you hold the wheel, you unconsciously correct the drift, but most of the time nobody has to tell you to do this, and people don't go over the science behind why, you just drive and spend all your time worrying about burning out the clutch, or if you have an automatic finding a song I guess.

[SkateZilla]

SkateZilla - sorry if i missed it. But I don't think I've seen anyone addressing it when my taxi light is pointing right. It points right before i even move ie. in its starting position.

 

if the Light moves to the right when you engage NWS, then it's a calibration / deadzone issue.

[Bushaman]

The light moves to the right at all times, as soon as I'm in the plane and turn on lights. When i turn on NWS, it stays where it was, slightly off to the right.

 

My feeling was its a calibration issue too. I am using a 10 year old x45 :). At the end of the day, its not a big deal. Just something I have always wondered about.

[PFunk1606688187]

The light moves to the right at all times, as soon as I'm in the plane and turn on lights. When i turn on NWS, it stays where it was, slightly off to the right.

 

My feeling was its a calibration issue too. I am using a 10 year old x45 :). At the end of the day, its not a big deal. Just something I have always wondered about.

 

If you use the RCtrl-Enter overlay to track your stick calibrations it should be pretty obvious whether or not your rudder is off center or not. I've also noticed the taxi light being off center when I turn NWS on when powering up a new aircraft, but I suspect this is just something in the game or something like the nosewheel being slightly off center and it doesn't center until you begin moving, since with NWS turned off the nosewheel doesn't turn with rudder, but it probably has some mechanism that locks it when it hits centre, but I'm not sure how it would achieve this other than with the wheel itself centring under normal movement to catch whatever latch there is to lock it, and since ground handling of aircraft likely would have this wheel unlatched for the purpose of pushing it into a parking space its likely the wheel wouldn't be locked when you turned it back on, even if it appeared to be nearly centre.

 

The other thing to note is that the nosewheel light is offset with the wheel carriage, so it'll never be properly centred, but you can tell if its pointing forward.

[Flagrum]

The light moves to the right at all times, as soon as I'm in the plane and turn on lights. When i turn on NWS, it stays where it was, slightly off to the right.

 

My feeling was its a calibration issue too. I am using a 10 year old x45 :). At the end of the day, its not a big deal. Just something I have always wondered about.

Just to make sure: the light is at an angle to the right and the effect is not just that it is not aligned with the center line of the plane, but has a small offset to the right (but pointing straight forward)?

[whartsell]

Just to make sure: the light is at an angle to the right and the effect is not just that it is not aligned with the center line of the plane, but has a small offset to the right (but pointing straight forward)?

 

Remember that the A-10s nosewheel is NOT on the centerline of the Aircraft. Its offset due to the GAU-8A

[Flagrum]

Remember that the A-10s nosewheel is NOT on the centerline of the Aircraft. Its offset due to the GAU-8A

That is why I asked him ...

[Bushaman]

Just to make sure: the light is at an angle to the right and the effect is not just that it is not aligned with the center line of the plane, but has a small offset to the right (but pointing straight forward)?

 

Yes Flagram, that describes the situation accuratly

[Bushaman]

Yes Flagram, that describes the situation accuratly

 

To clarify, its not jsut offset and pointing forward. Its actually pointing out and light is off center maybe at a 5 degree angle to the right. I'll post a track when i get back from vacation and see what you guys think.

[roadrabbit]

To clarify, its not jsut offset and pointing forward. Its actually pointing out and light is off center maybe at a 5 degree angle to the right. I'll post a track when i get back from vacation and see what you guys think.

 

:huh: Silly question - have you tried to taxy the aircraft forward on the runway a short distance whilst maintaining exactly on the centre-line? Is the nose-wheel steering green light illuminated whilst doing this? Does the light now still point off at 5 degs to one side?

 

If so, try to taxy the aircraft forwards on the runway, but this time turn to a 45 deg angle to the runway, move to the side of the runway, then turn back to the centre-line and regain the centre-line pointing exactly to the centre of the runway in the far distance. Does the runway light still have an off-set?

 

The results from the above will help to isolate the probelem :D

[Wrecking Crew]

If you use the RCtrl-Enter overlay to track your stick calibrations it should be pretty obvious whether or not your rudder is off center or not.

 

^^^ This

 

Plus, check the brakes with the RCntrl-Enter to be sure they are fully off. My toe brakes don't always go to zero, and they will cause a pull if one or the other is slightly engaged. A quick tap of the W key will zero the brakes.

 

WC

[Bushaman]

Thanks everyone! I have a lot of things to test out. Will let you know the results!

[FreeFall]

So does anyone else's taxi light point right, or is that just me?

 

It is not just you. I have noticed that as well.