How many screws does it take to attach a DC3 wing?
 

Many, many small ones!

This has always amazed me, don't know if it is a common method across all Douglas piston fleet.

It seems to work as these wings don't snap the screws and break off!

The wing attachment of the 747 and A380 keep me awake at night...


http://farm4.static.flickr.com/3139/...883128.jpg?v=0

An easy to remember number: 365 . . . so I was told many moons ago.

Almost right - 328 per side (102 x AN4-7A & 226 x AN410A bolts to be exact).
The bolts are torqued once on wing installation and then again after the first flight.
A real arm-acher!

And here was me thinking it was just a few rolls of duct tape ;)

Those very un-aerodynamic rows of bolts at the wing butt joints used to be covered with a neat cover strip in times of olds.

Problem was, when they finally corroded and failed, they would quietly slip unseen overboard beneath the cover strip. This would not be visible on a regular visual inspection.

The cover strips were finally removed after a fatal wing separation after too many bolts had disappeared, leaving too few to carry the loads.

Regards,

Old Smokey

While a young DC3 first officer, I recall being told that the spar was just two end-sections, held abutted together by these nuts and bolts.


I've mentioned before on Pprune about my regrets of not buying a little book of DC3 'mishaps'. Rather an understatement.

One picture was of a missing port wing...not far out from the bolts. It had somehow got back after hitting a mountain. The comment: "I bet this got their attention."

Anyone know about this book? It was on sale in a flying school near Austin some 15 years ago.

LR, can't speak as to the book, however, have you seen this website?

The DC-3 Hangar on douglasdc3.com DC3 C47 C-47

A lot of DC-3 information there.

Cheers. :ok:

While a young DC3 first officer, I recall being told that the spar was just two end-sections, held abutted together by these nuts and bolts.

Well, there's a little bit more to it. There are three spars in both the outer wing and centre section. Each one, top and bottom has a butt plate at the end of the caps and there are compression angles and waffle plates between the spars as well as a diaphragm to even out the load. Then you have some substantial doublers under the wing attachment angles themselves. The wings are held on by those 1/4" bolts around the chord, no others.
I seem to remember Northropp having something to do with the DC3 multi-cell wing design.

Look they are Engineers. We dont call them screws anymore.....

Holding the wing on that is. I'm retrospectively glad to hear it!




con, that site is certainly improved by turning off Adblock :E


One of One when we had proper airyplanes.

http://img.photobucket.com/albums/v7...apropBrian.jpg

those rolling hills behind the Dakota ? Date?

What was that cable for, ground power? No APU in the old bird.

I can just smell that Av Gas - better than Chanel for you guys !



Oh, so you called them screws once? What were pilots called then?

I'm not sure if it was Aberdeen or Edinburgh About 70-71



Sun-bronzed Sky gods of course.:}


In reality, it would probably be better not to ask. :{

Hello Steve,
Do you by ANY chance have a picture or drawing of how the outer wing attaches to the centre section of the DC3?

here's a video of the job;
Boeing Images - Douglas DC-3 Assembly Line, 1930s
there is aparantly no overlay of spars in the connection-line and no inner spanning of a possible spar-connection.
But the timeconsuming spanning of the row of bolts are to see!