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J230D rolls to the left


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Dear All,

 

I recently tried to stop the aircraft rolling to the left when the ailerons are in the neutral position by adjusting the left flap. In this case I made the adjustment to lower the left flap. It is working but the left flap is now visually obvious that it is lower than the right flap. Is this normal??? Does anyone know what other causes that could induce a roll to the left?

 

During flight it rolls to the left with ball in the centre, and the ailerons neutral. The ailerons have been confirmed neutral with control stick centred when on the ground. The roll rate increases with an increase in power even with ball centred.

 

Can anyone advise on how I can eliminate the left roll without such significant flap adjustment???

 

 

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First thing I would do is undo the flap change (that's an attempt at treating the symptom rather than the cause) and then I'd follow the Jabiru manual that specifically has all the rigging checks in it (http://www.jabiru.net.au/Manuals/Airframe Construction/Sections/Testing_Rigging_JALL.pdf )

 

I would be very surprised if you don't find an anomaly against the manual.

 

At the end of the day the question is better asked of Jabiru and only once you have performed and documented all tests in the linked manual.

 

I would also like to understand why you thought it best to adjust the flap, given its a roll issue why try fixing it with control surfaces closest to the main body of the aircraft? There the changes required are likely to be much greater in adjustment than at the end of the wing......And by that I'm not suggesting you just adjust aileron.......just do what the manual says to do first. If for example you have a bit of up aileron on the left and you introduce down flap on that side all you have done is achieve a neutral but in doing so introduced a drag element that doesn't need to be there and its asymmetrical which may well bite you later.

 

Lastly please be very honest in assessing your skills against those required, if having read the manual you feel you can easily do the work under your L1 rating then great, if not then no shame in getting a L2 or better to do the work. What Rego is the aircraft and do you crosshire it at all? If you do then you must not do the work yourself, unless your an L2 or better in which case you wouldn't be asking this question I would think.... The best skill a L1 can have, and one that will save your ar$e more than any other knowledge, is to know when you need more skilled assistance. Asking the question here is a great start.

 

Andy

 

P.S in the manual I linked to you can see they used a spirit level as the straight edge. I would do the check on concrete floor known to be level and I would be looking to see that the bubble for the horizontal was in the same place for both wingstips. This is only a gross check because flying attitude does not necessarily equate to the same attitude when sitting on landing gear. If the bubble is different at the outside of the wings when comparing both sides then there is a rigging error, or a tricycle gear error....given the roll Id be inclined to believe the former

 

P.P.S I note that page 8 of the test flight manual specifically deals with rigging issues and the corrections needed (http://www.jabiru.net.au/Manuals/Airframe Construction/Sections/Testing_Flight testing_JALL.pdf) I also note that J specify to use flap adjustment, which is only true if the aileron is already rigged correctly...here's hoping the whole eccentric bush thing isn't needed...that looks to be a pain to do!

 

 

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Dear All,I recently tried to stop the aircraft rolling to the left when the ailerons are in the neutral position by adjusting the left flap. In this case I made the adjustment to lower the left flap. It is working but the left flap is now visually obvious that it is lower than the right flap. Is this normal??? Does anyone know what other causes that could induce a roll to the left?

 

During flight it rolls to the left with ball in the centre, and the ailerons neutral. The ailerons have been confirmed neutral with control stick centred when on the ground. The roll rate increases with an increase in power even with ball centred.

 

Can anyone advise on how I can eliminate the left roll without such significant flap adjustment???

Step 1: Set it up on the ground with the wings laterally level, and verify that the skid ball is centred. If it's not, then the instrument is installed in the panel with a lateral tilt - and you must correct that before trying to use the skid ball to assess whether the aircraft is in lateral trim.

 

 

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Ide check the nose wheel or spat alignment . , A spat out of alignment with the propellor thrust line can be enough to induce roll , ive flown more than one that required adjustement.

 

Thats where ide start . After step 1 .

 

Cheers Mike

 

 

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Ide check the nose wheel or spat alignment . , A spat out of alignment with the propellor thrust line can be enough to induce roll , ive flown more than one that required adjustement.Thats where ide start . After step 1 .

Cheers Mike

Yes Mike,

 

Agree.

 

Mine was left main wheel spat. Not put back in alignment after a puncture fix.

 

Now have both spats marked with paint for correct realignment after brake adjustment etc.

 

Fixed the rolling to the left.

 

Phil

 

 

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Thanks ="[email protected], post: 450867, member: 94"]First thing I would do is undo the flap change (that's an attempt at treating the symptom rather than the cause) and then I'd follow the Jabiru manual that specifically has all the rigging checks in it (http://www.jabiru.net.au/Manuals/Airframe Construction/Sections/Testing_Rigging_JALL.pdf )

 

I would be very surprised if you don't find an anomaly against the manual.

 

At the end of the day the question is better asked of Jabiru and only once you have performed and documented all tests in the linked manual.

 

I would also like to understand why you thought it best to adjust the flap, given its a roll issue why try fixing it with control surfaces closest to the main body of the aircraft? There the changes required are likely to be much greater in adjustment than at the end of the wing......And by that I'm not suggesting you just adjust aileron.......just do what the manual says to do first. If for example you have a bit of up aileron on the left and you introduce down flap on that side all you have done is achieve a neutral but in doing so introduced a drag element that doesn't need to be there and its asymmetrical which may well bite you later.

 

Lastly please be very honest in assessing your skills against those required, if having read the manual you feel you can easily do the work under your L1 rating then great, if not then no shame in getting a L2 or better to do the work. What Rego is the aircraft and do you crosshire it at all? If you do then you must not do the work yourself, unless your an L2 or better in which case you wouldn't be asking this question I would think.... The best skill a L1 can have, and one that will save your ar$e more than any other knowledge, is to know when you need more skilled assistance. Asking the question here is a great start.

 

Andy

 

P.S in the manual I linked to you can see they used a spirit level as the straight edge. I would do the check on concrete floor known to be level and I would be looking to see that the bubble for the horizontal was in the same place for both wingstips. This is only a gross check because flying attitude does not necessarily equate to the same attitude when sitting on landing gear. If the bubble is different at the outside of the wings when comparing both sides then there is a rigging error, or a tricycle gear error....given the roll Id be inclined to believe the former

 

P.P.S I note that page 8 of the test flight manual specifically deals with rigging issues and the corrections needed (http://www.jabiru.net.au/Manuals/Airframe Construction/Sections/Testing_Flight testing_JALL.pdf) I also note that J specify to use flap adjustment, which is only true if the aileron is already rigged correctly...here's hoping the whole eccentric bush thing isn't needed...that looks to be a pain to do!

 

First thing I would do is undo the flap change (that's an attempt at treating the symptom rather than the cause) and then I'd follow the Jabiru manual that specifically has all the rigging checks in it (http://www.jabiru.net.au/Manuals/Airframe Construction/Sections/Testing_Rigging_JALL.pdf )I would be very surprised if you don't find an anomaly against the manual.

 

At the end of the day the question is better asked of Jabiru and only once you have performed and documented all tests in the linked manual.

 

I would also like to understand why you thought it best to adjust the flap, given its a roll issue why try fixing it with control surfaces closest to the main body of the aircraft? There the changes required are likely to be much greater in adjustment than at the end of the wing......And by that I'm not suggesting you just adjust aileron.......just do what the manual says to do first. If for example you have a bit of up aileron on the left and you introduce down flap on that side all you have done is achieve a neutral but in doing so introduced a drag element that doesn't need to be there and its asymmetrical which may well bite you later.

 

Lastly please be very honest in assessing your skills against those required, if having read the manual you feel you can easily do the work under your L1 rating then great, if not then no shame in getting a L2 or better to do the work. What Rego is the aircraft and do you crosshire it at all? If you do then you must not do the work yourself, unless your an L2 or better in which case you wouldn't be asking this question I would think.... The best skill a L1 can have, and one that will save your ar$e more than any other knowledge, is to know when you need more skilled assistance. Asking the question here is a great start.

 

Andy

 

P.S in the manual I linked to you can see they used a spirit level as the straight edge. I would do the check on concrete floor known to be level and I would be looking to see that the bubble for the horizontal was in the same place for both wingstips. This is only a gross check because flying attitude does not necessarily equate to the same attitude when sitting on landing gear. If the bubble is different at the outside of the wings when comparing both sides then there is a rigging error, or a tricycle gear error....given the roll Id be inclined to believe the former

 

P.P.S I note that page 8 of the test flight manual specifically deals with rigging issues and the corrections needed (http://www.jabiru.net.au/Manuals/Airframe Construction/Sections/Testing_Flight testing_JALL.pdf) I also note that J specify to use flap adjustment, which is only true if the aileron is already rigged correctly...here's hoping the whole eccentric bush thing isn't needed...that looks to be a pain to do!

Thank you for your advice and link. I was advised by a L2 to adjust the flaps but it seems strange that the adjustment needs to be so much. I think verifying the bubble is a good first step and will do this first.

 

 

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Ide check the nose wheel or spat alignment . , A spat out of alignment with the propellor thrust line can be enough to induce roll , ive flown more than one that required adjustement.Thats where ide start . After step 1 .

Cheers Mike

Thx Mike.

 

 

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When I was building my SK, a check of the wings showed they were not at exactly the same incidence. Jabiru supplied bearings drilled off-centre to fix the problem. I had used a "u" tube between the leading and trailing edge of each wing to find the problem, which really wasn't hard to fix.

 

 

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