Return-Path: Received: from imo-d05.mx.aol.com ([205.188.157.37]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Sun, 31 Dec 2000 09:52:32 -0500 Received: from Sky2high@aol.com by imo-d05.mx.aol.com (mail_out_v28.35.) id k.4b.587aad5 (3952); Sun, 31 Dec 2000 10:00:24 -0500 (EST) From: Sky2high@aol.com Message-ID: <4b.587aad5.2780a408@aol.com> Date: Sun, 31 Dec 2000 10:00:24 EST Subject: Legacy Horizontal Stabilizer and Elevator Pressure Release Vents To: lancair.list@olsusa.com, 73761.230@compuserve.com X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com Mime-Version: 1.0 John,

You wrote:

<<A good workshop overall....however, there was one major oversight.  When we
closed the horizontal stabilizer and elevators, we did not drill the required
1/4" vent holes in the ribs.>>

Did you take pictures as you went along for your log?  I remember that the
holes were already drilled in mine and I added a few more.  I have pictures
and I can make them available to Marv for posting.

Take out page 2-9 (I think that's the number) that represents the view of the
H-stab and elevators showing the ribs as a reference:

Each elevator has only 2 chambers.  The inboard chamber on the trim tabbed
elevator is vented thru the tab actuator push rod hole.  If you used the 1/4"
rod thru a holes drilled into the elevator horns and into the hinges for
alignment during skin close out, the hole in the horn rib should take care of
the outboard chambers since the outboard rib does not completely closeout the
trailing edge.  I can't tell from my pictures, but I think there were holes
in the elevator mid span ribs.  After the elevators are finished (rudders
clearances cut) the inboard trailing edge of the rib can be drilled.  The
trim tab won't need a hole since it is foam filled.  One must be careful with
hole placement so that rain (in flight or on the ground) cannot fill the
chambers.

There are eight (8) chambers in the H-stab.  In mine, the ribs and forward
spars all had holes drilled in them and the aft center chamber had a hole
drilled in the bottom skin as the final vent.  If you have no holes in the
ribs and spars, the center chambers could be vented, thru holes in the
bottom, to the tailcone.  I have not seen the H-stab fairings yet, but maybe
the mid-board chambers could be vented into the fairings?  Otherwise, thru
the main aft spar.   The outboard chambers could be vented thru holes at the
ouboard end of the main spar. maybe one high on the spar and on low to ensure
drainage...

Even the 320's had these holes since an early builder had separations from
the pressure differential.

Scott Krueger
N92EX
Legacy #2