Mailing List lml@lancaironline.net Message #19466
From: Marvin Kaye <marv@lancaironline.net>
Subject: Re: IVP tail modification now available
Date: Mon, 07 Jul 2003 13:35:09 -0400
To: <lml>
Posted for "Joseph Trepicone" <jtrepico@columbus.rr.com>:

Attached is a tail modification currently being produced and marketed by a builder in Bend, OR.  Its an e-glass overlay (or carbon for those without antennas in the tail section)  which essentially reproduces (or so I'm told) the tail section of the new Sentry.  As we probably all know the Sentry utilizes the bottom fuselage, wings and horizontal of the IV with a different fuselage top and tail cone.  The overlay is about 3-1/2" higher than the standard IV at the transition point between the vertical and the fuselage.  It creates a very sharp edge.

Some thoughts and questions:

1)  Is this a structural weak point in the IV design that requires additional structure?  Personally I don't know of any structural failures of this area however we have received a service bulletin regarding the securing of the aft fuselage access panel (see SB066-0203).  The bulletin states "...access panels are an essential part of the structural integrity of the fuselage... -8 screws are less apt to strip..."
2)  The Sentry is probably intended for aerobatics (light aerobatics I imagine) and that may be the reason for the tail modification.  However would the higher allowable gross weight and faster potential speeds of the Propjet justify or benefit a similar modification?
3)  Is this portion of the IV tail cone intended/designed to flex or deflect to absorb and dissipate specific loads and, if so, would this modification cause those loads to be transferred to other portions of the aircraft not intended to take such loads?

I believe this mod is only on one IV and hasn't flown yet.  It certainly changes (maybe even esthetically improves) the lines of an already beautiful contour but I vowed to avoid adding weight for esthetic reasons alone.

Any thoughts?

Joe Trepicone IVPT

If you'd like some information contact:
Justin Stacy
541-788-1042
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