Return-Path: Received: from [65.33.166.39] (account ) by logan.com (CommuniGate Pro WebUser 4.1.1) with HTTP id 2537023 for lml@lancaironline.net; Thu, 21 Aug 2003 20:45:59 -0400 From: "Marvin Kaye" Subject: iv-p heat damaged cowl To: lml X-Mailer: CommuniGate Pro WebUser Interface v.4.1.1 Date: Thu, 21 Aug 2003 20:45:59 -0400 Message-ID: In-Reply-To: <007e01c3684e$a1b41fa0$2d113742@wrimain> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Posted for "john wright" : My iv-p now has 771hrs on it and it is in for annual inspection. Upon removing the lower cowling along the lateral walls of the cowling next to the turbos, the inner skin shows evidence of heat damage. This is an all carbon fiber cowling with the large (Dolly Parton) exhaust tunnels. The cowling is reinforced along the lower half with what appears to be a honey comb layer sandwiched between the outer and inner skins. When the inner skin is pressed on with a finger it is somewhat brittle and the honeycomb collapses beneath the pressure. The inner skin doesn't actually crack or flake but you can tell that it has delaminated. There is no evidence of damage to the outer skin. The paint is not bubbled nor is there any weakness demonstrated when the skin is pressed upon. There is another iv-p on the field where I hangar and his is worse than mine! I called Lancair today and spoke with Justin who said he has noticed some evidence of heat on the factory lower cowling also, but doesn't seem to view that as having much significance. He commented that prepreg doesn't melt until 260*. He also mentioned that some paint the inside of their cowling with tank sealer which he says is somewhat heat resistant and allows less air resistence to air flow through the cowling. He suggested coring out the heat damaged core and applying 6 BIDS of carbon fiber if I am inclined to repair it. My A&P on the field is somewhat of a Bonanza expert and he comments that on the turbo bonanzas there is a heat shield made out of two metal layers with insulation sandwiched in between that bolts right on to the turbo to contain the heat and on the cowling there is applied some type of heat reflecting material (maybe like the firewall blanket?) to protect the skin. He points out that the Bonanza cowling allows significantly more clearance than the iv-p. I would like to know if anyone else has observed this on their iv-p and has any recommendations on how to fix the problem. John Wright Colorado Springs