Flaperon Rigging Question (Mk2)

[waterboy]

Can anyone tell me what the angle of incidence of the flaperons on a Mk2 should be in their neutral position, with flaps NOT extended?

Also, what are the reference point(s) on the flaperons and the aircraft against which this angle should be measured?

I am trying to re-rig a 1991 aircraft and the builder's manual I have, which is in loose leaf format, is missing this information.

Thanks in advance.

[GDN]

Same KF2 same question and same documentation...

[waterboy]

Sorry, but can you be more specific? Do you mean that this question has already been answered in another thread, and if so then could you point me in the right direction, please?

I have searched the forum but not found what I'm looking for.

Thanks.

[GDN]

No as i have to push the stick right to fly with no roll i tried to find a method to check the correct setting of my flaperons.

So no answer and so same interrogation like you.

[waterboy]

GDN,

Replying to my own question, I've now found the answer, and it was in my builder's manual all the time, though I couldn't see for looking.

It's in section CF (Covering and Finishing) page CF18, diagram CF12.

If you don't have that page, let me know and I will email you a scan/photo, but in words the neutral position with the flap lever fully forward and the control stick centred is as follows:

The datum on the flaperons is the flat bottom surface of the flaperon. Extend that flat line forwards (using a suitable straight edge) and measure the distance to the underside of the forward wing spar (leading edge of wing). The gap between the forward spar and the straight edge should be 1 inch.

HTH

[GDN]

Will see my documentation.
Thanks.

If the 2 flaperons are not symetrical on wich part do you correct the setting ?

[waterboy]

I forgot to mention yesterday that the flaperon/wing spar measurement should be made immediately outboard of the wing struts.

In your documentation, do you have the section F (Fuselage), and specifically page F8 which shows the complete control system as an exploded drawing? The following paragraphs make reference to part numbers in that drawing:

Level the FBK-7 Mixer Bellcrank and clamp to keep it level.

Adjust the length of the aileron control tube FCT-21 by extending/reducing its associated rod ends in order to centre the control sticks.

IMPORTANT: If you are extending any rod ends, ensure that at least 1+1/4 times the thread diameter is located within the rod, in order to ensure adequate purchase. Some female rod end bearings have a "witness hole" drilled through the shank - if you can pass a length of siezing wire through that hole then there is insufficient thread within it.

If there is insufficient thread in the rod ends of FCT-21 to centre the sticks (bearing in mind the proviso above) then look to see whether you can safely adjust the male/female rod end bearing combination (FRE-48 & FRE-49) which leads from the bellcrank FBK-6 to the part No. FCT-20 (the tube connecting the two control sticks together).

Once the sticks have been centred and while the mixer bellcrank is still level, adjust the flaperon neutral position by first ensuring that the flap lever is fully forward. If your Mk2 is complying with the AD that mandates the flaps be permanently wired up then it should already be so.

Measure the flaperon/wingspar distance (1inch) as previously discussed and adjust this setting by adjusting the threaded rod(s) FRU-47. Remember the warning about rod ends above.

If you find that there is insufficient adjustment possible in the threaded rods to set the flaperons properly to neutral, it may be that when the AD regarding the flaps-wired-up mandate was complied with, a clamping plate was added to the frame which affected the positioning of the flap controls (this is what I have found in my aircraft). As a result, a longer U Joint FU-58 at the lower end of push-pull rod FCT-25 was substituted (by a previous owner) on each side to compensate, but unfortunately they seem to have made the replacements too long (1+7/8 inches) and my aircraft has been flying around since then with a small amount of flaps applied. I have now fabricated a complete new set of U Joints FU-58 with two being the original length (1+1/8in) and two slightly shorter than the too-long ones I removed (1+5/8in). I haven't rigged that setup yet - I will let you know how I get on.

Hope that helps. If you need a copy of the exploded diagram please let me know.

[GDN]

Thanks a lot that's clear i'll see on monday my documentation at work ;-)

[akflyer]

I am guessing that the flaps wired up AD is just for you folks on the "other side of the pond". I have several hundred hours in mod I and II and use the flaperons every take off and landing. Too bad there is an AD over there for that as it really makes a difference getting in and out short!

[GDN]

Level the FBK-7 Mixer Bellcrank and clamp to keep it level.

Adjust the length of the aileron control tube FCT-21 by extending/reducing its associated rod ends in order to centre the control sticks.
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Hope that helps. If you need a copy of the exploded diagram please let me know.

How can you level the FBK-7 ?
Horizontal with a spirit level ?
If think it is important that the airplane is really horizontal before checking the fbk-7 ? And how do you fix the FBK-7 when leveled to check if the stick is vertical ?

2 persons for that no ?

Thanks a lot with your method i know now how to check...now how to control...

see you