High wing aircraft question???

[Cargo_ramp]

Dunno if this thread exsists?and i'm sorry if it does.. but could anyone tell me how the manufacturers actually attach the wings to highwing A/C like the Dash 8 or BAE146? I know its a strange question..but i was flying with Air canada last week on a Dash 8-200 and we hit some really choppy turbulence..and i wondered how the wings stayed on?...Cheers.

[chuks]

It depends on the price category. Hot glue for some of the lesser Cessnas, I believe, ranging upwards to big steel bolts.

There was quite a fuss made in the States at one point following a sudden twang, after which wooden wings for transport category aircraft went right out of fashion.

[john_tullamarine]

Putting Chuks' amusing response to one side ... the detail can be quite involved .. but, conceptually, it is not much different to joining a timber beam or two (wing main and rear spars) to a structure (fuselage) by the use of a few U-bolts.

I wouldn't worry too much about the fuselage falling off the wings during turbulence ...

[Keith.Williams.]

The design of aircraft structures obviously gets quite complex if we try to look at it in geat detail. This is particulary true when we look at the structure of large aircraft. But if we take a very simplistic view we can boil it down to two basic principles:

a. Use only as much material as is absolutely necessary to carry the anticipated loads and provide the required safety margins.

b. Prevent excessive stresses from becoming concentrated in any part or area of the structure.

When attaching high (or indeed low wings) we must ensure that the loads transmitted from the wings are dispersed into the surrounding fuselage without producing any excessively high stress areas.

With many low wing arrangements the loads from the wings are carried into a strengthened longitudinal component called a keel beam. This is attached to the fuselage skin by means of a series of hoop beams or frames which form part of the skeleton of the fuselage. If we were to examine the inside of a fuselage with the insulation and soundproofing material removed, we wouild see that the spacing between the frames is smallest in the area where the wings are attached. We would also usualy see that the skin is thickest in this area.

High wing structures use a similar method but without a keel beam. As stated in previous posts, the most common method of actually attaching the wings to the keel beam or frames is by means of nuts and bolts.

[kabz]

On the blanik gliders (the only plane I've ever helped take apart), two metal 'tongues' (wing spars I think) are pinned into a box section in the fusilage. The pins are not that large (about 6 in long) and are simply tapped down to hold the wings on, then a safety clip goes through the bottom of the pin to hold it in place.

The front pin is the important one, and the trailing pin holds the wing from moving forwards or backwards.

However, despite this fairly light looking arrangement, I have never heard of a failure in flight.

In practice I believe the wing will break first.