Mission: Overwatch - plane veers HARD on takeoff

[kharne]

I'm having a lot of trouble taking off in the Overwatch mission. As soon as I'm rolling, the plane starts to veer very hard to the right. I try to steer left, but the nosewheel tire just blows out every time. I thought I was leaving NWS engaged too long, but it happens almost immediately.

 

I figured my joystick calibration was way off, but I checked it and it seems fine. Then I unplugged it and tried using the keyboard, and the exact same thing happens.

 

I understand how to use trim to maintain level flight, but I'm obviously missing something about taking off. I can do the tutorial with no problem at all. I even went back to it because I thought I must be missing something, but I had no problem taking off straight and level on the tutorial. I've tried pressing the takeoff trim button, but it's either already set or I'm doing something wrong.

 

Any suggestions on what else to check? And can someone explain how the takeoff trim button works? I'm getting a bit frustrated. I've searched, but all of the threads I've found are about the slight roll to the right while flying, which I know how to adjust the trim to compensate for.

[Frostiken]

Right wheelbrake stuck?

[Zenra]

Are you perhaps taking off with a significant crosswind component?

 

I have a lot of trouble with the plane pulling to one side during takeoff runs, but it always seems to coincide with a crosswind. I disengage NWS passing 50 KIAS, but the rudder seems to have little authority. It's almost like the effect is magnified on the ground - once I manage to get the wheels off the ground the rudder works better. I am thinking this might have something to do with the SAS - I know to turn if off for crosswind landings, but have not seen anything here, nor have I tried yet, to take off with yaw SAS disengaged. Need to try that...

[Sinky]

Are you perhaps taking off with a significant crosswind component?

 

I have a lot of trouble with the plane pulling to one side during takeoff runs, but it always seems to coincide with a crosswind. I disengage NWS passing 50 KIAS, but the rudder seems to have little authority. It's almost like the effect is magnified on the ground - once I manage to get the wheels off the ground the rudder works better. I am thinking this might have something to do with the SAS - I know to turn if off for crosswind landings, but have not seen anything here, nor have I tried yet, to take off with yaw SAS disengaged. Need to try that...

 

Your front wheel is giving resistance since it's locked as it should be at over 50 knots. This is why you see more movement when you lift the nose. Doesn't have much of a problem pivoting on the main gear though.

 

The original poster may want to try deflecting his control stick into the crosswind if there is one. Don't think not doing this would cause the nose wheel to pop but anything is worth a try.

[Scratchy]

I tried this mission after reading the OP. I'd never tried it before and am wondering why. It was fun until a SAM got me :D

 

About the takeoff:

Yes. there's a crosswind component. The wind is about 180 at 14knots; which is about a 40 degree component on your right-hand side. Couple that with the rough surface on this particular airport and it is a tricky take-off.

 

Here is how I approach this kind of take-off. First, if there's a x-wind, you'll notice the aircraft weather-vaneing (not a word, I know) into the x-wind. Your nose will want to turn into the wind. So, that's your clue as to from which direction is wind is coming. Keep the nose pointed down the runway. Practice...practice. Next, a slight aileron into the wind as your speed increases. Hold this small correction through rotation. As you lift-off, you see the aircraft nose turn into the wind and at that point neutralize the aileron. You'll climb out with the appropriate attitude.

 

As to when to disengage the nose-wheel steering: I disengage at 60 knots. I don't know if this is proper, but it works for me.

 

Finally, I think the crosswind reaction of the aircraft is a bit exaggerated. I don't know this for sure, having never flown a A-10. But, it does seem a bit much.

 

I'll have to try turning off SAS and a poster above mentioned. That might be a contributor to the difficulty. If you haven't tried flying without SAS, you should. It is illuminating as to what this system does for stability.

Edited May 9, 2011 by Scratchy
Spelling fix and added comment on SAS.

[Sinky]

Aileron crosswind correcting prior to or during rotation is a big no-no with any airplane.

 

I mean whilst rolling, never done it myself but I've heard it mentioned on the forums. Might have been whilst taxiing though and I'm getting things mixed up.

Edited May 9, 2011 by Sinky

[chaos]

I'm having a lot of trouble taking off in the Overwatch mission. As soon as I'm rolling, the plane starts to veer very hard to the right. I try to steer left, but the nosewheel tire just blows out every time. I thought I was leaving NWS engaged too long, but it happens almost immediately.

 

Check all the things that affect nosewheel steering and braking...

*rudder pedal calibration (if you have pedals)

*check Emer. Brake Handle in

*check Hydr. Pressures (L and R)

The Emer Brake System is serviced by the R hydr. Sys. so that would be my prime- suspect. Did you accidentally pull it out?

 

USMC_Trev:

Aileron crosswind correcting prior to or during rotation is a big no-no with any airplane.

 

Please explain because, if this is true, I've been doing it the wrong way for 24 years ;-)

Edited May 9, 2011 by chaos

[kharne]

First of all, thank you for the responses :)

 

I realized after I posted that it was a cross-wind causing my problems. I managed to take off with some heavy rudder input (after cutting off my wingman) and felt the difference just flying from waypoint to waypoint, and changing directions. I didn't realize the wind would effect the plane that way, and I think I just need more practice.

 

Still not sure about the take-off trim button though. Does that just reset your trim? Can someone explain how it works?

 

Also, are there any good trim tutorials or threads? I've only been using it for small adjustments, and could use some advice on how I should be setting it up. Thanks for all the help!

[nomdeplume]

Yes, take-off trim just resets it to neutral. In a fresh plane your trim is already neutral so it doesn't really do anything, but if you land and then go to takeoff again you reset the trim to avoid unexpected handling. Remember to hold it down until the light comes on.

 

As I understand it, a real pilot will move the stick to where they need it for the speed/pitch/roll they're maintaining, and then use trim to cancel out the pressure they're needing to apply to the stick to maintain their desired flight parameters. The trim essentially sets a new 'center' position for the stick, so the pilot doesn't have to hold it in a particular position all the time.

 

Typically this is small adjustments - you don't use the trim to help you throw the plane around the sky, but rather to maintain a particular course for long periods without constant exertion.

[Sinky]

Best way I can explain trim is like this... Say your flying at a speed of 230 and you trim the aircraft for hands off level flight and you suddenly increase the throttle you will see the nose rise. You are trimmed for level flight at 230 knots, if you increase throttle you speed will climb and the aircraft will nose up to bring the speed back down to 230.

 

In theory if you were flying at the same speed and pulled the throttle into idle you would see the aircraft enter a 230 knot descent. I feel the A-10C's trim doesn't feel as precise as other aircraft, might be the sim or it might be like that in the real A-10C.

 

I'm talking about pitch trim only here.

[TheTunaTaster]

Aileron crosswind correcting prior to or during rotation is a big no-no with any airplane.

 

Are you talking about the a-10 specifically? Because my flight instructor flew f-4s in Vietnam (for credibility's sake) and he says to turn the yoke in the direction of the wind's source.

[Jive]

Aileron into wind for crosswind take off roll is a perfectly valid technique.

[Evil.Bonsai]

Yes, take-off trim just resets it to neutral. In a fresh plane your trim is already neutral so it doesn't really do anything, but if you land and then go to takeoff again you reset the trim to avoid unexpected handling. Remember to hold it down until the light comes on.

 

 

Thank you for this. Was wondering what it did, as it didn't seem to do anything that I could tell. Especially since not once have I pushed and HELD it down until a light came on. If needed, I would just hold stick in position for stable flight, then when I got to a level point, just trimmed then (coolie hat)

[andyfoot]

I had been flying for a while before I realised you have to press and hold the TOT button. One day I pressed it and noticed the virtual stick move, so I pressed it again and watched it move to the Take Off Trim position, at which point the TOT light came on. It was one of those many "Ah Hah" moments I've had with this great Sim!

[HammerUK9]

 

USMC_Trev:

Aileron crosswind correcting prior to or during rotation is a big no-no with any airplane.

 

Please explain because, if this is true, I've been doing it the wrong way for 24 years ;-)

 

Ditto - and got taught to do it by FAA PPL, JAA PPL AND RAF EFT training programmes :)

[Kaiza]

Yawing during takeoff with a crosswind is a function of uneven friction between the main landing gear. Because the wind is lifting one wing up it puts less friction on the upwind wheel and more friction on the downwind wheel. This causes you to yaw towards the wheel of most friction (the direction the wind is travelling). As mentioned above, the way to combat this is to put in to wind stick (aileron) which balances the friction between the wheels and allows you to maintain better directional control.

[Fish]

Switch on the control input mini display with

 

RCTRL ENTER

 

Invaluable tool to see all you input activity.

 

Think Trim reset is LCTRL t

The tool above will help you check its working

[lobo]

Taking off in a stiff crosswind you most definitely do need aileron into wind. A quote from my old "From the Ground Up"... "During the xwind takeoff, aileron control is held to the upwind side and the aircraft is held straight with rudder. Use full aileron deflection initially, then as speed increases progressively reduce the amount of deflection to keep the wings level." Been doing this for the last 30 years irl in up to 36kt xwinds. Without the aileron input on a slippery runway you are likely going off the side. Same thing on landing btw use aileron into wind and rudder to maintain control.

 

Also see this from Boeing Chief test pilot:

http://www.smartcockpit.com/data/pdfs/flightops/flyingtechnique/Crosswind_Guidelines.pdf

[DUSTY]

**EDIT*** Goddamnit - I've gotta stop jumping into posting before realising that thread's are alread two pages long and I haven't yet read the second page!!! :D

 

All of what I've said below has been already addressed but it took me a while to type it so don't particularly feel like deleting it!

 

------------------

 

That's a very good explanation nomdeplume, basically the trim is used to keep the aircraft balanced during all flight regiemes and at different speeds, power settings etc.

 

A basic understanding of aerodynamics tells us that an increase in airspeed will make an aircrafts nose pitch up, just like inversely a decease in airspeed will result in the nose dropping. If your aircraft is in trim (balanced) flying straight and level at 230KIAS and you then idle the throttles but want to maintain the same altitude, you will need to trim the nose up to prevent having to hold back stick pressure to maintain altitude.

 

A good example of using trim which might help you to understand is that when entering say a 30deg nose down dive for a CCIP bombing run, the pilots will generally trim the nose down prior to entering the dive. The amount of nose down trim is a guess to begin with but is refined as the dive is established and the pilot is using the HUD to get the release cue for the weapon. What trimming the nose down in this situation does is to prevent the aircraft from wanting to pitch its nose up with the inevitable increase in airspeed during the dive. Resulting in the pilot having a centred stick position allowing for greater ease in manoeuvring for the weapon release without having to use constant forward stick pressure to stop the aircraft from pitching up.

 

I hope I have explained this well enough, but at the end of the day I would reccomend just going and flying the A-10 at different airspeeds and power settings and trying to maintain straight and level flight without needing to make a stick input. This should make the effects of trim (along the vertical axis anyway) pretty self explanatory.

 

Aileron and Rudder trim are very similar concepts which i won't bother going into but i find the primary use for aileron trim (and it is extremely handy in the A10) is to balance your aircraft with an asymmetric load. i.e when you have dropped weapons on the right wing pylons but still have the left wing loaded. Aileron trim simply lets you retrim the aircraft to prevent it banking toward the weighted wing which again centralises the stick and takes pressure off the pilot.

 

cheers

Edited October 22, 2011 by |DUSTY|