Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Mon, 27 Sep 2004 13:52:05 -0400 Message-ID: X-Original-Return-Path: Received: from tomts20-srv.bellnexxia.net ([209.226.175.74] verified) by logan.com (CommuniGate Pro SMTP 4.2.3) with ESMTP id 433910 for lml@lancaironline.net; Mon, 27 Sep 2004 11:42:37 -0400 Received-SPF: none receiver=logan.com; client-ip=209.226.175.74; envelope-from=ian.crowe@sympatico.ca Received: from crowe ([69.159.75.171]) by tomts20-srv.bellnexxia.net (InterMail vM.5.01.06.10 201-253-122-130-110-20040306) with SMTP id <20040927154205.JDOS1968.tomts20-srv.bellnexxia.net@crowe> for ; Mon, 27 Sep 2004 11:42:05 -0400 X-Original-Message-ID: <001501c4a4a8$a2020980$6721fea9@crowe> From: "Ian B. Crowe" X-Original-To: "Lancair Mailing List" Subject: Fw: Your door problem X-Original-Date: Mon, 27 Sep 2004 11:42:43 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01C4A487.19FA70C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0012_01C4A487.19FA70C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ----- Original Message -----=20 From: Ian B. Crowe=20 To: goconnell@dodo.com.au=20 Sent: Monday, September 27, 2004 10:16 AM Subject: Your door problem There is no spring to help the door close. The spring fitted is to open = the door when you go to emergency extension of the gear. When you do = this, all the pressure is released and the nose gear door and the two = inner doors on the main gear are pushed open by springs. My right hand side inner door has a habit of closing much later than the = other doors and I have partially explained it, at least to myself by = blaming the prop wash. However it does close eventually and is fine on = the ground. Have you flown a full circuit and then asked the tower to = check again? If I have the plane on the jacks and I retract the gear the mains go up = first, then the nose gear retracts and FINALLY the inner doors and the = nose door close as the pressure builds up to the pressure switch cut off = point. I have gauges on my system and the pressure can be seen clearly = as it rises and the inner doors finally close. This tells me that = loading the springs requires a deal of effort and the extra air loads = may be the problem if other factors are in play. However the majority of 360's work OK so the question is how does your = plane differ? It is obvious that the air loads are a factor if the door = is fine on the ground. However the force available to close the door = must be very marginal if the air loads are sufficient to keep the door = open. Is it the cylinder itself? Is the actuating rod bent? Is the = cylinder properly aligned to give an in line pull to the door. Is the = bracket on the door the correct size in terms of the height of the = cylinder attachment point above the door? (This distance determines the = leverage you get) Are you quite sure that you did not use teflon tape = to seal the threads on the cylinder and that some if it is not blocking = the ingress/egress to/from the cylinder. Do you have two hoses to the = cylinder? i.e. not only a closing but also an opening hose? If so you = will need to check that as the door closes the fluid on the other side = of the piston can flow freely back to the reservoir. Does the door move = easily on its hinge? Once you are 100% sure that all of the above is OK, = you could take off the emergency spring that opens the door and fly the = aircraft and see if the door closes then. This involves some element of = risk beacause if you have a real emergency the nose gear door will only = open under the weight of the gear pushing it down plus the thrust of the = emergency extension cylinder. This is your call! =20 If it does not work with the spring off then you are on to the = verificaion of the ability of the sequence valve to provide unimpeded = flow. This goes to the physical condition of the valve as well as the = adjustment. If all is well there then you need to do the check I = mentioned to see that there is no blockage in the line, which is = unlikely but........ If you end up wih no results from the foregoing it would be a good idea = to get two pressure gauges and "T" them into the lines at the pump. = They will tell you what is happening to the pressures in the system, = bearing in mind that the pressure at any point in a system like ours is = the same as at any other point. The gauges are not expensive, $20 to = $25 each. I cannot think what else you could do other than go into the mail list = archives which is a treasure trove of other people's experiences and in = some cases, solutions. Where do you live in Oz? Haven't been there in years but used to go = into Sydney from Los Angeles and then out west to the Pilbarra. What a = place. The only place I know where the cold water in your hotel room = would scald you after its trip across the desert! ------=_NextPart_000_0012_01C4A487.19FA70C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
----- Original Message -----=20
From: Ian B.=20 Crowe
Sent: Monday, September 27, 2004 10:16 AM
Subject: Your door problem

There is no spring to help the door = close. =20 The spring fitted is to open the door when you go to emergency extension = of the=20 gear.  When you do this, all the pressure is released and the nose = gear=20 door and the two inner doors on the main gear are pushed open by=20 springs.
 
My right hand side inner door has a = habit of=20 closing much later than the other doors and I have partially explained = it, at=20 least to myself by blaming the prop wash.  However it does close = eventually=20 and is fine on the ground.  Have you flown a full circuit and then = asked=20 the tower to check again?
 
If I have the plane on the jacks and I = retract the=20 gear the mains go up first, then the nose gear retracts and FINALLY the = inner=20 doors and the nose door close as the pressure builds up to the pressure = switch=20 cut off point.  I have gauges on my system and the pressure can be = seen=20 clearly as it rises and the inner doors finally close.  This tells = me that=20 loading the springs requires a deal of effort and the extra air loads = may be the=20 problem if other factors are in play.
 
However the majority of 360's work OK = so the=20 question is how does your plane differ?  It is obvious that the air = loads=20 are a factor if the door is fine on the ground.  However the force=20 available to close the door must be very marginal if the air loads are=20 sufficient to keep the door open.  Is it the cylinder itself?  = Is the=20 actuating rod bent?  Is the cylinder properly aligned to give an in = line=20 pull to the door.  Is the bracket on the door the correct size in = terms of=20 the height of the cylinder attachment point above the door? (This = distance=20 determines the leverage you get)  Are you quite sure that you did = not use=20 teflon tape to seal the threads on the cylinder and that some if it is = not=20 blocking the ingress/egress to/from the cylinder.   Do you = have=20 two hoses to the cylinder?  i.e. not only a closing  but = also an=20 opening hose?  If so you will need to check that as the door closes = the=20 fluid on the other side of the piston can flow freely back to the=20 reservoir.  Does the door move easily on its hinge? Once you are = 100% sure=20 that all of the above is OK,  you could take off the emergency = spring that=20 opens the door and fly the aircraft and see if the door closes = then.  This=20 involves some element of risk beacause if you have a real emergency the = nose=20 gear door will only open under the weight of the gear pushing it down = plus the=20 thrust of the  emergency extension cylinder.  This is your=20 call!   
 
If it does not work with the spring off = then you=20 are on to the verificaion of the ability of the sequence valve to = provide=20 unimpeded flow.  This goes to the physical condition of the valve = as well=20 as the adjustment.  If all is well there then you need to do the = check I=20 mentioned to see that there is no blockage in the line, which is = unlikely=20 but........
 
If you end up wih no results from the = foregoing it=20 would be a good idea to get two pressure gauges and "T" them into the = lines at=20 the pump.  They will tell you what is happening to the pressures in = the=20 system, bearing in mind that the pressure at any point in a system like = ours is=20 the same as at any other point.  The gauges are not expensive, $20 = to $25=20 each.
 
I cannot think what else you could do = other than go=20 into the mail list archives which is a treasure trove of other people's=20 experiences and in some cases, solutions.
 
Where do you live in Oz?  Haven't = been there=20 in years but used to go into Sydney from Los Angeles and then out west = to the=20 Pilbarra.  What a place.  The only place I know where the cold = water=20 in your hotel room would scald you after its trip across the=20 desert!
 
 
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