One Low Wing

[swift1b]

I recently noticed that the left wing on my BC12D is 2 inches lower then the right wing? I installed new bungees 2 years ago. Is this normal?

[M Towsley]

Re: One Low Wing

Mine is like that, not sure why. It has been mentioned on here before that sometimes the landing gear mounts were originally welded on in an incorrect location when being built.

[Guest]

Re: One Low Wing

Mine is that way too.

Check your bungees and the bungee bumpers as a loose bungee on one side or a more flatten bumper on one side will cause a difference at the tips.

However mine is sloped for none of those reasons but rather as far I can figure out that the left leg is a bit different than that right leg. Maybe a repair was done in the past to mine.

Dave

p.s. one year I noticed that in the Wicks catalog they listed the o.d. of the 6.00 x 6 tires they sold. I bought one with a larger o.d. and one with the smaller o.d. and mounted them appropriately. They were only different by a 1/4" or 3/8" as I recall.

[mike lutz]

Re: One Low Wing

might be worth looking at the rubber gear stop bumpers on the bottom of the fuselage under the shock cords.

[Robert Lees]

Re: One Low Wing

The lateral levelling reference is the tube that sits behind the seat sling, just under your shoulder blades when seated in the aircraft. Assuming it's not been damaged in the past, if you get this tube horizontal (as you should, doing a W&B) then 2" at the wingtip is a minor discrepancy, compared with the accuracy of the spirit level used to judge lateral position. As mentioned, tyre pressure makes a big change to wingtip height.

If it stalls straight (i.e. just a mush without excessive wing drop) then I wouldn't worry.

But do check the condition of your bungees, just in case.

Rob

[M Towsley]

Re: One Low Wing

Maybe someone can tell me how you accurately measure across that cross tube with cord around it holding the seat sling with the baggage sling attached over that. Thanks.

[Robert Lees]

Re: One Low Wing

Maybe someone can tell me how you accurately measure across that cross tube with cord around it holding the seat sling with the baggage sling attached over that. Thanks.

It's easy, Marty

First you remove the doors for ease of access, or tie them both wide open with a piece of string across the cowl.
Then remove all the interior trim for access to the 4 screws that hold the front edge /wood batten of the seat sling, and then swear very loudly that at least one of the captive nuts holding on the batten has broken off.

Then you unlace the sling at the bottom frame (behind your arse) and the top frame (under your shoulder blades). It won't unlace properly, so you will have to cut some of it out. Then take a minute to wonder why on earth you are doing all this, and then go and get a cup of tea.

Eventually (having awaited 3 weeks for delivery of new captive nuts from your favourite supplier) you replace the wooden batten, and re-lace all the eyelets (ignoring the torn ones) right up to the point where you forgot about the cut lace 3 weeks ago.

Another week delay, asking Grandma which haberdashery to get heavy-duty lace cord from. The rest is easy: reassemble, make sure the doors close, and go fly.

You get to the end of the runway ready for take-off and then realise you forgot to do the darn level measurement anyway

[M Towsley]

Re: One Low Wing

Um, yea......no, I don't think so. To add to that, my baggage sling is glued to the top of the rope holding the seat sling in-place. That is how it was when I got it and that is how it is now after replacing the seat sling/wrapping cord a couple of years ago.

Has to be a better way...

[Hank Jarrett]

Re: One Low Wing

There is. You get a stick that is straight and stiff. Drive a small finishing nail through each end so the point comes out the same on both sides. When you put the piece of wood across with the nail points contacting the tube through the cord gaps the top of the wood is parallel to the tube. Level the piece of wood and the plane is level too.

I have had to solve WAY TOO MANY problems like this on my plane!!!

The plane sitting out of level on the gear when you are finished doesn't make a bit of difference. You only need to trammel so the stab is parallel to the cross tube, the fin is perpendicular to the stab and the wings have the same dihedrial and sweep on each side with reference to the cross tube. This is for FLIGHT! The gear alignment is done for ground handling. Whole new set of alignments.

Hank

[Hank Jarrett]

Re: One Low Wing

You should also consider a fixture for the prop shaft to check down and side thrust (if you are severely retentive). ;-)

[PA1195]

Re: One Low Wing

Look up trammel tool or points. Make your own cross rod to fit the fuselage width. We use then to square wings before recovering, don't we?

Edit: I have a set of points that my paternal grandfather gave me back in the '50's (plus a plumb bob and a .22 pistol to shoot rats). I use the points frequently to measure woodworking projects and adjust the rear axle on my Harley. The rat gun gets warmed up during bird hunting season. The plumb bob's attached to the on/off light string on my bench light. Grandpa would be pleased.

Gary

[astjp2]

Re: One Low Wing

+- 5 Degrees is close enough....

Maybe someone can tell me how you accurately measure across that cross tube with cord around it holding the seat sling with the baggage sling attached over that. Thanks.

[Hank Jarrett]

Re: One Low Wing

LOL!!! Tim might actually be right in the "real world", but I would shoot for less than a quarter bubble. When I was working on the Navy A-6 we got a plane in that had ALL OF THE DIHEDRAL in one side! The plane flew just fine! Drove Grumman crazy.

Hank

That was ONE bent up airplane!

[swift1b]

Re: One Low Wing

Thanks to all for all your excellent input. I am confident I will be able to pinpoint the cause of the low wing!

Swift1b

[swift1b]

Re: One Low Wing

Thanks to all for all your excellent input. I am confident I will be able to pinpoint the cause of the low wing!

Swift1b