24323 Vallentine 2nd challenge

[Clark]

Wanted to open tail of fuselage as I figured worst corrosion would probably be found there. As I did so I got excited as there wasn't any fabric on bottom of last tail triangle area. I thought that's pretty clever. Next day I went out to vacuum and take pictures in that area. As I did so I realized the vertical tail tubing wasn't quite right and found the vertical tail post cracked almost all the way around. About .25 - 3/8 ths inch above weld.

[Hank Jarrett]

It is amazing how they put in redundant load paths back there. They had to know there was going to be hidden damage in the future. At least it is pretty easy to weld repair. Almost EVERY T fuselage I have seen had damage back in the "Taylorcraft Terrible Triangle" area. Some would make your hair stand on end, but none I saw ever fully failed! Did see one photo of a crippled tail that let loose on both lower longerons on landing. The tail bent up and twisted on a hard tail drop, but no injuries and they stopped the plane safely. The seats were probably ruined.

[Robert Lees]

I had the same in my fuselage just about 6 months ago (the give-away was someone walking behind the aircraft as it was taxying. The tailwheel and aft fabric wobbled about all over the place. And this was just 10 years after I had punch-tested that area during my rebuild! And re-sealed with TubeSeal!

As Hank says, it's a simple repair.

Incidentally, we have twelve Pitts Specials of varying ages based at my field...they have ALL suffered the same failure. Reasoning for this is that::
A. The Pitts Special was developed from a Taylorcraft
B. There is an inherent metallurgical change just above that weld (as in all welds)
C. The aft cluster of all steel-tube-built aircraft eventually suffer (Cubs, Aeroncas, etc)
D. Age.

Fortunately, it's not a life-threatening failure.

Rob

[Guest]

When you repair it put a drain hole where the red dot is.

Water inside the tube may be responsible for it rusting thru.

Dave

[Clark]

Thanks Dave, I've heard there was supposed to be one, but didn't know where, and haven't seen any on this aircraft so far. Do I remember right that there is an AD?

[Guest]

I don't recall an AD.

[Clark]

I think I confused it with the Gear and drain hole on strut.

[Mike S]

When you repair it put a drain hole where the red dot is.

Water inside the tube may be responsible for it rusting thru.

Dave

On mine there is what looks like a phenolic plug stuck in there where you have the red dot in photo, guess I should try to pull it out and see what happens?

[Guest]

On mine there is what looks like a phenolic plug stuck in there where you have the red dot in photo, guess I should try to pull it out and see what happens?

Might be interesting. :-)