X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 01 Feb 2007 09:23:27 -0500 Message-ID: X-Original-Return-Path: Received: from imo-d21.mx.aol.com ([205.188.144.207] verified) by logan.com (CommuniGate Pro SMTP 5.1.5) with ESMTP id 1803498 for lml@lancaironline.net; Thu, 01 Feb 2007 01:42:28 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.144.207; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-d21.mx.aol.com (mail_out_v38_r7.6.) id q.c4d.d279322 (40522) for ; Thu, 1 Feb 2007 01:41:26 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Thu, 1 Feb 2007 01:41:24 EST Subject: Re: [LML] Re: Gear-door electromagnets X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1170312084" X-Mailer: 9.0 Security Edition for Windows sub 5358 X-Spam-Flag: NO -------------------------------1170312084 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 1/31/2007 3:53:15 P.M. Central Standard Time, marv@lancaironline.net writes: Has anybody ever wondered why the gear doors get sucked open in the first place? There should be high pressure under the wing, now low. Maybe there's VERY high pressure inside the wheel well. If so, how does it get there? Adam, For main gear doors it may not be a matter of sucking them open because they may never get closed. Those doors also have a cambered shape that may have them operating like a wing with their own lift downward once there is air flow and just before they would actually close. The only Lancair inboard main gear doors with this problem appear to be on the Legacy. Partially the cause is that they are so big. The nose gear door is a different story on the LNC2 series. The aft part of the door is beyond the hinge and usually is not stiff enough. There is no real air pressure against the door from the outside because it is behind the cowl that extends several inches below the fuselage in the area in front of the door. Finally, if the nose gear leg seal is not perfect (between the firewall and the wheel well), lower cowl engine cooling air can enter the wheel well and force its way out at the tail of the nose gear door. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) A man has got to know his limitations. -------------------------------1170312084 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 1/31/2007 3:53:15 P.M. Central Standard Time,=20 marv@lancaironline.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>Has=20 anybody ever wondered why the gear doors get sucked open in the=20 first
  place? There should be high pressure under the wing, now l= ow.=20 Maybe there's
  VERY high pressure inside the wheel well. If so, h= ow=20 does it get there?
Adam,
 
For main gear doors it may not be a matter of sucking them open because= =20 they may never get closed.  Those doors also have a cambered shape that= may=20 have them operating like a wing with their own lift downward once there is a= ir=20 flow and just before they would actually close.  The only Lancair=20 inboard main gear doors with this problem appear to be on the Legacy.&n= bsp;=20 Partially the cause is that they are so big.
 
The nose gear door is a different story on the LNC2 series.  The a= ft=20 part of the door is beyond the hinge and usually is not stiff enough. =20 There is no real air pressure against the door from the outside because= it=20 is behind the cowl that extends several inches below the fuselage in the are= a in=20 front of the door.  Finally, if the nose gear leg seal is not perfect=20 (between the firewall and the wheel well), lower cowl engine cooling air can= =20 enter the wheel well and force its way out at the tail of the nose gear door= .=20
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

A m= an=20 has got to know his limitations.
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