Return-Path: Sender: (Marvin Kaye) To: LML Date: Thu, 18 Apr 2002 19:02:04 -0400 Message-ID: X-Original-Return-Path: Received: from [198.207.223.228] (HELO babbler.bmc.com) by logan.com (CommuniGate Pro SMTP 3.5.9) with ESMTP id 1170320 for lml@lancaironline.net; Thu, 18 Apr 2002 17:11:17 -0400 Received: from localhost.localdomain (localhost [127.0.0.1]) by babbler.bmc.com (8.10.2/8.10.2) with ESMTP id g3ILEEW19691 for ; Thu, 18 Apr 2002 16:14:14 -0500 (CDT) Received: from pdavis (pdavis@localhost) by localhost.localdomain (8.11.6/8.11.2) with ESMTP id g3ILAXT11716 for ; Thu, 18 Apr 2002 16:10:33 -0500 X-Original-Message-Id: <200204182110.g3ILAXT11716@localhost.localdomain> X-Authentication-Warning: localhost.localdomain: pdavis owned process doing -bs X-Mailer: exmh version 2.4 06/23/2000 with nmh-1.0.4 Pgp-Action: PGP/MIME-signclear; rfc822=off; originator="Paul Davis " From: "Paul Davis" Reply-to: "Paul Davis" X-Original-To: lml@lancaironline.net (Lancair Mailing List) Subject: Re: [LML] Re: Brake pads and tires In-Reply-To: Your message of "Thu, 18 Apr 2002 10:10:15 EDT." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Original-Date: Thu, 18 Apr 2002 16:10:33 -0500 X-Original-Sender: pdavis@pdavis.bmc.com Not being hampered by actually knowing anything about designing an aircraft, I've long wondered why there are no brakes on the nose wheels of tricycle-gear airplanes. With other vehicles (2, 3 and 4 wheel): Front wheel braking typically accounts for about 70% of total braking. Front wheel braking is substantially more effective than rear wheel braking. Counter-intuitively, decreasing the lateral force available (hard braking or wheel locking) on the rear wheel(s) is much more likely to result in a loss of control of the vehicle than similar decrease on the front wheel(s). Oversteer. Yeah, I realize you'd likely lose the ability to steer by differential braking, but a steerable nose wheel fixes that. Doesn't seem to be a problem for kid's tricycles, golf carts and such. I don't think that "nose dive" is a plausible concern as I *think* the amount of weight transfer to the front wheel would be the same for a given total braking force applied from either the front or rear wheel(s). I wondered if anyone had ever tried the experiment but I can't find a reference and the only tricycle gear aircraft I know of with front wheel brakes is the Viking powered parasail. I suspect Viking drivers don't worry a lot about braking distance. Could it be something as simple as that main gear breaking is "good enough"? I mean, what's the point in being able to stop in 300 feet, if you still need 600 feet for takeoff? Must be something I'm missing here. Just wondering. Paul Davis INTP pdavis@bmc.com Phone (713)918-1550