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                           TeamGrumman-List Digest Archive
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                     Total Messages Posted Sun 02/15/04: 1
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Today's Message Index:
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     1. 10:11 AM - Horizontal attach, next step  (TeamGrumman@aol.com)
 
 
 
________________________________  Message 1  _____________________________________


Time: 10:11:35 AM PST US
From: TeamGrumman@aol.com
Subject: TeamGrumman-List: Horizontal attach, next step

--> TeamGrumman-List message posted by: TeamGrumman@aol.com

This, in my opinion, is more than a crack in a corner.  

If one looks at the design of the structure in the aft end (from the
structure just ahead of the ELT tray, to the last bulkhead where the rear horizontal
spar is attached) visualize, if you will, a structure that acts as a ridgid=20box
to support the entire horizontal and keep it from twisting.   If the
horizontal is allowed to twist, it could act as a trim tab that has a variable
angle
of attack.   Worse case is flutter.  

Back to the structure just ahead of the ELT tray.   This is where the
horizontal on the Traveler was attached.   It's an order of magnitude stronger
than
the light stringers to which the much larger Tiger/Cheetah horizontal is
attached.   It looks to me like the Tiger/Cheetah was rushed into production without
a serious re-engineering of the loads to be expected in the corners of the
torque box created by the new horizontal support.  

I would propose a duplicate (or something like it) of the structure
originally used on the Traveler to support the forward horizontal spar, overlayed
on
the lighter production stringers on the Tiger/Cheetah.  

Time for a DER.


In a message dated 02/14/04 07:27:12 PM, flyv35b@ashcreekwireless.com writes:

> I would agree with you Gary.=A0 In any kind of riveted joint you wouldn't
> think twice about replacing the whole member due to a simple crack.=A0 Who
> knows, the crack may have been there for hundreds of hours and is going
> nowhere. I (personally) think that if it is just a small crack in either the
> horizontal or vertical angle, where they join, that easy and satisfactory
> solution would be to rivet an L-shaped piece that goes around the corner and
> rivets to both angles.=A0 Use .040 say and put a nice .5-1.0 in. radius at the
> intersection.=A0 End of story and crack.=A0 I wouldn't even consider this=20a
> major repair and no specific approval is needed (that's my opinion of
> course).
>