[apatti]

Dwg 21 View A-A' (lower left corner) shows that you bend the F887 longeron up (as jigged) 2 23/32". This is so it will meet with the WD 803 on the firewall. However, on Dwg 20 Detail H (lower left), the firewall is shown as being mounted on the jig so that F801C is 3" above the fuse reference plane (FRP). This puts the WD 803 a little over 3" above the FRP. Why do you only bend the longeron 2 23/32" and not a little over 3"? I first thought that maybe the longeron is not even with the FRP at the 804 bulkhead. However, Dwg 20 Detail B shows that it is flush.

Also, do you push the longeron as far as it will go in the WD 803? Or do you leave a little space for vibration?

Thanks for any assistance.

 

[briand]

Check out detail H on Dwg 20. Looks like the firewall angle (not the WD 803) is at the 3" dim but the picture should explain it better than I can put it in words.

 

[apatti]

Check out detail H on Dwg 20. Looks like the firewall angle (not the WD 803) is at the 3" dim but the picture should explain it better than I can put it in words.

Briand,
Thanks for the reply. F801C is the firewall angle. I agree it is the firewall angle that is supposed to be 3".

I think I may have just figured out at least part of my problem. I am placing the longeron "inside" WD 803. A review of the drawing shows that it should be outside the WD 803. Duh! Otherwise there would be a huge transition problem for the skin at the aft end of the WD 803 / longeron intersection. Now it makes more sense!

The idea to check this came to me while I was doing something totally unrelated to airplane building. Isn't it amazing how the subconscious mind works when, in this case, the conscious mind was completely confused.