Wing sweep question

[sandymunro]

What experience is on record of delberate forward sweep to offset Angle Valve with Heavy Prop Forward C.of G.???

This is a pretty old thread but I would appreciate any input from Kevin Horton and others.

Sandy. Very slow QB

[Maxrate]

Sam,
You mentioned vertical stab offset in post #6. Can you elaborate. I have talked to those who have/haven't offset the vertical. What produces the best results in the field? Sorry not trying to hijack the thread starter

[scrollF4]

Originally Posted by Sam Buchanan

Absolutely nothing out of the ordinary.

OH, SNAP! I got it.

[David-aviator]

My first airplane, a Long EZ, was certified by a FAA inspector.

I told him the wing sweep from left to right was off by 5/8". His response was, don't sweat it, I've seen Cessna's coming off the line off by over an inch.

You do not have a problem...

[RV6_flyer]

Originally Posted by Sam Buchanan

Matt, you may get some replies with engineering principles referenced, but my reply was based on seeing many RV builders rig their planes. A 1/4" variance at the wingtip is a tiny "error" that field experience has proven will have no effect on the flying qualities of your plane. There are other factors that would have much greater impact (control surface trailing edge radius, pushrod symmetry, vertical stab offset, landing gear fairing alignment, etc, etc......).

I am another one like Sam that have seen small variance in wing sweep and with no noticeable effect. See Kevin's engineering calculations of effect to back these statements up.

[DanBaier]

Three thoughts -

1 - there's probably a prize to be claimed for having it turn out that close.

2 - were you to measure this a few days later, you might very well conclude the variation in sweep had moved to a different measure and / or direction. (Airplanes sometimes do this in the dark of night in the hangar when no one is around.)

3 - if someone ever does question it, tell them that you did it intentionally so that when a stall should occur, you would have the peace of mind of knowing that it will always break in the same direction (not true, but sounds good).

Dan

[vfrazier]

1/4" variance in sweep is great!

Now, go measure the height of each wingtip from the ground up. If that also is 1/4".... go buy a lottery ticket immediately!! (Many RVs have a very noticeable higher wingtip on one side due to tire pressure, cumulative errors, etc, etc... and it's nothing to worry about either!)

[Alex Edwards]

And then of course there are aircraft that are designed to have a different amount of sweep on each wing:

[Joness0154]

A few weeks ago I had the pleasure of getting a tour of the 737 assembly line at Renton.

Up until very recently, Boeing used to attach the wings of these aircraft using plumb bobs, levels, etc....and, according to our guide, this meant each wing could be mounted slightly off from each other.

In my opinion, if a small variation is OK for a certificated airliner, your RV will be OK too