Mailing List lml@lancaironline.net Message #58113
From: Tom & Beth Sullivan <toms1@chartermi.net>
Sender: <marv@lancaironline.net>
Subject: Re: IVPT A/C & Aft fuselage area questions
Date: Mon, 25 Apr 2011 13:13:15 -0400
To: <lml@lancaironline.net>

   Thanks for the replies.  My particular IVP will be powered by a Walters, so not sure if that has the same CG issues.  At any rate, I'm aware of the aft CG challenge and have been building with that concern in mind.  I eliminated 8 pounds from the rudder counterweight by moving it forward; even with the leading edge of the vertical (have seen and talked to others having done the same).  That alone should help considerably with this issue.  I also have an entirely pre-preg enclosure to the wheel well area, which cut the weight of that down from the "elephant butt" by half.  Many turbine builders have added a fuel tank behind the second row seat; I have not (just the 30 gallon belly tank).

A few others brought up some more things to consider; oxygen tank and static ports (great points).  Any idea what size O2 cylinder is common and where to purchase it?

Still looking for a few pictures of an A/C unit inside the plane (on the back pressure bulkhead).

Thanks much,

Tom

 

Bob wrote:

Tom,

I placed my ELT in the aft fuselage just to the rear of the fuselage access panel in my IV-P. I also have a TruTrac pitch servo mounted to the belcrank support structure just behind the MLG wheel well, with its operating arm linked to the belcrank itself. The TruTrac, and most GA autopilots, attach servos to the control pushrods, rather than to the trim tabs.

 Keep in mind that anything you add behind the wing spar that didn’t come in the kit moves the CG aft.  To offset this, I added 1” aluminum spacers between the engine mount and the firewall to move the engine forward. Even so, I run out of CG before I get to my (declared and tested) max weight of 3600#--using any reasonable passenger/baggage loading plan.  I’d seriously consider this mod as you build. IV-Ps tend to be tail heavy—because most of us homebuilders tend to “overbuild” the plans a bit…and almost all of it winds up aft of the CG.

 You are correct to complete all possible build items before installing the top! 5 times harder to work any interior things with the top on.  

 Bob

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