X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 13 Nov 2012 11:13:29 -0500 Message-ID: X-Original-Return-Path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122] verified) by logan.com (CommuniGate Pro SMTP 6.0c2) with ESMTP id 5876048 for lml@lancaironline.net; Mon, 12 Nov 2012 23:49:12 -0500 Received-SPF: pass receiver=logan.com; client-ip=71.74.56.122; envelope-from=kkellner1@new.rr.com X-Original-Return-Path: X-Authority-Analysis: v=2.0 cv=NLdXCjGg c=1 sm=0 a=obLwkm3ISv3u5N1fLH+lKQ==:17 a=Iy1csxky15oA:10 a=yhQU3oAz_ZYA:10 a=05ChyHeVI94A:10 a=ayC55rCoAAAA:8 a=T3EV-oW35MwA:10 a=Ia-xEzejAAAA:8 a=C_IRinGWAAAA:8 a=LJNHRzvFAAAA:8 a=W3-THr4qiVEda7NWG-IA:9 a=pILNOxqGKmIA:10 a=EzXvWhQp4_cA:10 a=si9q_4b84H0A:10 a=3q8PDF_K8bIA:10 a=pGLkceISAAAA:8 a=znQYIsC67f5sJUgSNaEA:9 a=_W_S_7VecoQA:10 a=tXsnliwV7b4A:10 a=MSl-tDqOz04A:10 a=0x2QTyFowjtG9Guw:21 a=obLwkm3ISv3u5N1fLH+lKQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 70.92.78.168 Received: from [70.92.78.168] ([70.92.78.168:3818] helo=D4SSJS91) by hrndva-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id BF/A5-14780-421D1A05; Tue, 13 Nov 2012 04:48:37 +0000 X-Original-Message-ID: From: "Ken" X-Original-To: , "William A. Hogarty" References: Subject: Re: [LML] Dukes pressurization controller X-Original-Date: Mon, 12 Nov 2012 22:48:35 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002A_01CDC127.D8EFC550" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 This is a multi-part message in MIME format. ------=_NextPart_000_002A_01CDC127.D8EFC550 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable My 2001 kit had a dump valve standard. It could be activated by a panel = mounted switch and also by a micro switch mounted in contact with the = drum that the gear handle is screwed into. The micro switch was = intended to control the dump valve similarly to a squat switch, but = activated by selecting gear down instead of weight on wheels. I have since removed the micro switch. During an attempt to lower the = gear the micro switch tang became wedged in the drum and jammed the gear = handle. There I was, with the gear up and no way to get the gear down. = The gear handle would not go down far enough to route the hydraulic = fluid in the right direction so the hand pump would also not work. = Because I am luckier than I am smart, this occurred during my last = condition inspection while the airplane was on jacks and I was doing the = standard and emergency gear extension/retraction checks instead of while = flying. I decided to remove the micro switch instead of replace it because the = only function is serves is to prevent having a pressurized cabin when = you open the door after landing if you forgot to reset the controller = during descent. With the low power settings in the pattern, and typical = taxi to parking my IV-P is unpressurized by the time I park even without = the dump valve being activated. So, with micro switch having no real = world value and also having demonstrated the potential for jamming the = gear handle in the up position, forcing a gear up landing, I removed it. Ken Kellner IV-P N14LK ----- Original Message -----=20 From: William A. Hogarty=20 To: lml@lancaironline.net=20 Sent: Sunday, November 11, 2012 11:09 AM Subject: Re: [LML] Dukes pressurization controller Good discussion on the controller so I thought that I would add my 2 = cents. The dump valve was added to the flow controller some time after 1994. = I purchased the 1st pressurized kit that had the bulkheads and gearbox = installed by the factory and the the flow controller I received did not = have the dump valve. As I recalled it was added some months later after = a lot of discussion following the fiirst inflight fire.. Also, there was a mod added to the flow controller a couple of years = back. Cant recall the details but I could look it up is anyone is = interested.=20 Regards, Bill H. On Fri, Nov 9, 2012 at 8:45 AM, Jack Morgan = wrote: Just a quick note on the controller. Bob's excellent description = below is all good. The Dukes controller is an "aneroid" controller which = needs no electric power to operate once the airport elevation is set.=20 The electrical control for altitude setting in the cabin controls an = electric motor in the controller which sets the aneroid so that it = controls cabin pressure to just above the set airport altitude. This = insures no pressurization is present at landing. Once set, an electrical = failure will not cause any problem for the cabin pressurization system.=20 Jack Morgan On Nov 9, 2012, at 6:01 AM, Lancair Mailing List wrote: From: Robert R Pastusek Subject: RE: [LML] IVP cabin heat Date: November 8, 2012 3:16:51 PM EST To: lml@lancaironline.net Dico, I=92ll answer via the LML as this may be of interest to other = Lancair owners/operators. First the disclaimer: The description below covers Lancair IV-Ps = built using the parts provided by Lancair, and following the building = manual. I have seen a couple of other configurations out there=85the = product of =93individualism,=94 and occasionally better ideas=85 So = check to be sure your system is plumbed as described below before trying = these things. The IV-P uses bleed air from the engine turbochargers to both = pressurize and heat the cockpit. The compressed air pipe exiting each = turbocharger has a port added to tap off some of the air for the cabin. = (By the way, this air has run through the turbochargers, but does not = yet have any fuel added, so is breathable.) This port should have a = =93sonic nozzle=94 either welded to the port itself, or installed in the = SCAT/SCEET line that=92s attached. The sonic nozzle provides a relative = constant flow of air to the cabin heating/pressurization system over the = typical range of pressure in the turbocharger system (typically = 25=94-38=94 MP at cruise power settings). Depending on the power setting = (MP), this compressed air is near ambient temperature to quite hot (200+ = degrees), and is the =93hot=94 feed for the cabin heating/pressurization = system. It is routed via SCAT/SCEET ducting to a flow controller (a = gold-anodized round canister a bit smaller than a coffee can) mounted to = the top engine-side of the firewall. The cabin heating/pressurization system has a second =93cool=94 = feed that starts with an additional port welded to the engine inlet air = ducting downstream of the large intercoolers on each side of the engine. = These ports are connected with SCAT tubing to a third intercooler on the = forward left chin of the engine, opposite the alternator. For the = =93cool=94 feed, compressed air passes through the side intercoolers, = then through this third intercooler and then via a single SCAT tube to = the flow controller. Note that both hot and cool feeds are = =93relative.=94 The hot side can yield luke-warm air if the engine power = is low, and the cool side is, at best, a few degrees above ambient; = usually not cool at all in Florida in the summertime. The above compressed air is fed into the cabin directly from the = flow controller on the firewall. With the cabin temperature control in = the cold position, flow from the hot side (above) is completely blocked = and all pressurization air is being fed into the cockpit from the cool = side. With the temperature control in the hot position, the cool side = feed is blocked and the hot side feed is fully opened. As a side note, = the flow controller has a second function that=92s important. The = =93pressurization control=94 in the cockpit is connected to a flapper = valve in the flow controller that alternatively opens a port allowing = pressurized air to flow into the cockpit (normal operation) and closes a = =93dump port=94 that feeds air, via a SCAT tube, down the forward side = of the firewall to the engine exhaust area. When in the dump position, = this valve opens the dump port and closes the port into the cabin, = dumping the pressurized air overboard. This might be useful in the case = of an engine fire or other contamination of the inlet air=85not common, = but could really ruin your day if it happened at altitude. So why no heat? If you haven=92t done so, it would be very = beneficial to verify that the controls/components discussed work as = described above. IF there are leaks or the system is not = connected/configured correctly, all bets are off. The next task, assuming the system is plumbed and operating = correctly, is actually generating some heat=85especially up where Dico = lives=85 At low power settings, the air coming directly off the = turbochargers is not hot. Your choices (via the cabin temperature = control) of compressed air for pressurization are cool and cold. 25=94 = of MP is about the minimum that will maintain cabin pressurization, and = the compressed air off the turbos is just a bit above ambient = temperature. Above 32=94 of MP, the exit air is approaching 200 degrees = and will keep the cockpit toasty in any conditions I=92ve seen to = date=85but I don=92t like to run my engine at that high a power setting. = So to answer your specific question, heat the cabin by: 1) Ensuring the cabin pressure dump control is closed, and = not leaking air/heat out the dump vent. 2) Set the cabin temperature control to full hot 3) Increase engine power (MP), with care to the engine, to = get the needed heat. Note: I=92ve actually taken to running the MP between 29-30=94 = during the winter time just to keep Judy warm and happy. A good = investment=85 =20 Just a last bit of information to =93polish off=94 the system: The = flow of high pressure air into the cockpit is =93unregulated=94 as long = as the dump control is closed, and although relatively constant, is = subject to changes in both pressure and flow rate depending on engine = power setting. The cockpit pressure is maintained by controlling the = outflow (controlled leakage) of air through the Dukes controller mounted = in a =93bucket=94 under the rear seat. This is an = electrically-controlled exhaust valve and takes some time to adjust to = flow and pressure changes. It=92s therefore easy to =93get ahead=94 of = the pressurization system by rapidly changing the engine power setting. = Most of us have learned to compensate for this, but if you=92re getting = a lot of ear-popping and complaints from your passengers, try changing = the engine power more gradually, especially at level-off and start of = descent. =85And I=92m sure you=92ve all discovered by now what happens = if you pull the engine back to below 25=94 MP or so while at altitude? = The air in the cabin actually back-flows through the engine and the = cabin altitude goes quickly to the outside pressure altitude. Solution: = Keep the MP above 25=94 until you=92re down out of the flight levels; = then slowly bring it back more if needed=85 Hope this helps! Bob ------=_NextPart_000_002A_01CDC127.D8EFC550 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
My 2001 kit had a dump valve standard.  It could be activated = by a=20 panel mounted switch and also by a micro switch mounted in contact with = the drum=20 that the gear handle is screwed into.  The micro switch was = intended to=20 control the dump valve similarly to a squat switch, but activated by = selecting=20 gear down instead of weight on wheels.
 
I have since removed the micro switch.  During an attempt = to=20 lower the gear the micro switch tang became wedged in the drum and = jammed the=20 gear handle.  There I was, with the gear up and no way to get = the gear=20 down.  The gear handle would not go down far enough to route the = hydraulic=20 fluid in the right direction so the hand pump would also not work.  = Because=20 I am luckier than I am smart, this occurred during my last condition = inspection=20 while the airplane was on jacks and I was doing the standard and = emergency gear=20 extension/retraction checks instead of while flying.
 
I decided to remove the micro switch instead of replace it because = the=20 only function is serves is to prevent having a pressurized cabin = when you=20 open the door after landing if you forgot to reset the = controller=20 during descent.  With the low power settings in the pattern,=20 and typical taxi to parking my IV-P is unpressurized by the = time I=20 park even without the dump valve being activated.  So, = with micro=20 switch having no real world value and also having demonstrated = the=20 potential for jamming the gear handle in the up position, = forcing=20 a gear up landing, I removed it.
 
Ken Kellner
IV-P  N14LK
 
----- Original Message -----
From:=20 William A.=20 Hogarty
Sent: Sunday, November 11, 2012 = 11:09=20 AM
Subject: Re: [LML] Dukes = pressurization=20 controller

Good discussion on the controller so I thought that I would add = my 2=20 cents.
 
The dump valve was added to the flow controller some time after=20 1994.  I purchased the 1st pressurized kit that had the bulkheads = and=20 gearbox installed by the factory and the the flow controller I = received did=20 not have the dump valve.  As I recalled it was added some months = later=20 after a lot of discussion following the fiirst inflight fire..
 
Also, there was a mod added to the flow controller a couple = of years=20 back. Cant recall the details but I could look it up is anyone is = interested. 
Regards, Bill H.
 
 
 
 
On Fri, Nov 9, 2012 at 8:45 AM, Jack Morgan <jmorgan1023@comcast.net> = wrote:
Just a quick note on the = controller.=20 Bob's excellent description below is all good. The Dukes controller = is an=20 "aneroid" controller which needs no electric power to operate once = the=20 airport elevation is set.=20
The electrical control for altitude setting in the cabin = controls an=20 electric motor in the controller which sets the aneroid so that it = controls=20 cabin pressure to just above the set airport altitude. This insures = no=20 pressurization is present at landing. Once set, an electrical = failure will=20 not cause any problem for the cabin pressurization system.=20

Jack Morgan

On Nov 9, 2012, at 6:01 AM, Lancair Mailing List = wrote:

From: Robert R = Pastusek <rpastusek@htii.com>
Subject: RE: [LML] = IVP cabin=20 heat
Date: November 8, = 2012 3:16:51=20 PM EST
To: lml@lancaironline.net


Dico,
 
I=92ll=20 answer via the LML as this may be of interest to other Lancair=20 owners/operators.
 
First=20 the disclaimer: The description below covers Lancair IV-Ps built = using the=20 parts provided by Lancair, and following the building manual. I = have seen=20 a couple of other configurations out there=85the product of = =93individualism,=94=20 and occasionally better ideas=85 So check to be sure your system = is plumbed=20 as described below before trying these = things.
 
The=20 IV-P uses bleed air from the engine turbochargers to both = pressurize and=20 heat the cockpit. The compressed air pipe exiting each = turbocharger has a=20 port added to tap off some of the air for the cabin. (By the way, = this air=20 has run through the turbochargers, but does not yet have any fuel = added,=20 so is breathable.) This port should have a =93sonic nozzle=94 = either welded to=20 the port itself, or installed in the SCAT/SCEET line that=92s = attached. The=20 sonic nozzle provides a relative constant flow of air to the cabin = heating/pressurization system over the typical range of pressure = in the=20 turbocharger system (typically 25=94-38=94 MP at cruise power = settings).=20 Depending on the power setting (MP), this compressed air is near = ambient=20 temperature to quite hot (200+ degrees), and is the =93hot=94 feed = for the=20 cabin heating/pressurization system. It is routed via SCAT/SCEET = ducting=20 to a flow controller (a gold-anodized round canister a bit smaller = than a=20 coffee can) mounted to the top engine-side of the=20 firewall.   The=20 cabin heating/pressurization system has a second =93cool=94 feed = that starts=20 with an additional port welded to the engine inlet air ducting = downstream=20 of the large intercoolers on each side of the engine. These ports = are=20 connected with SCAT tubing to a third intercooler on the forward = left chin=20 of the engine, opposite the alternator. For the =93cool=94 feed, = compressed=20 air passes through the side intercoolers, then through this third=20 intercooler and then via a single SCAT tube to the flow = controller. Note=20 that both hot and cool feeds are =93relative.=94 The hot side can=20 yield luke-warm air if the engine = power is=20 low, and the cool side is, at best, a few degrees above ambient; = usually=20 not cool at all in Florida in the = summertime.   The=20 above compressed air is fed into the cabin directly from the flow=20 controller on the firewall. With the cabin temperature control in = the cold=20 position, flow from the hot side (above) is completely blocked and = all=20 pressurization air is being fed into the cockpit from the cool = side. With=20 the temperature control in the hot position, the cool side feed is = blocked=20 and the hot side feed is fully opened. As a side note, the flow = controller=20 has a second function that=92s important. The =93pressurization = control=94 in=20 the cockpit is connected to a flapper valve in the flow controller = that=20 alternatively opens a port allowing pressurized air to flow into = the=20 cockpit (normal operation) and closes a =93dump port=94 that feeds = air, via a=20 SCAT tube, down the forward side of the firewall to the engine = exhaust=20 area. When in the dump position, this valve opens the dump port = and closes=20 the port into the cabin, dumping the pressurized air overboard. = This might=20 be useful in the case of an engine fire or other contamination of = the=20 inlet air=85not common, but could really ruin your day if it = happened at=20 altitude.   So=20 why no heat?  If you haven=92t = done so,=20 it would be very beneficial to verify that the controls/components = discussed work as described above. IF there are leaks or the = system is not=20 connected/configured correctly, all bets are=20 off.   The=20 next task, assuming the system is plumbed and operating correctly, = is=20 actually generating some heat=85especially up where Dico lives=85 = At low power=20 settings, the air coming directly off the turbochargers is not = hot. Your=20 choices (via the cabin temperature control) of compressed air for=20 pressurization are cool and cold. 25=94 of MP is about the minimum = that will=20 maintain cabin pressurization, and the compressed air off=20 the turbos is = just a bit=20 above ambient temperature. Above 32=94 of MP, the exit air is = approaching=20 200 degrees and will keep the cockpit toasty in any conditions = I=92ve seen=20 to date=85but I don=92t like to run my engine at that high a power = setting. So=20 to answer your specific question, heat the cabin=20 by: 1)      Ensuring=20 the cabin pressure dump control is closed, and not leaking = air/heat out=20 the dump vent. 2)      Set=20 the cabin temperature control to full = hot 3)      Increase=20 engine power (MP), with care to the engine, to get the needed=20 heat. Note:  I=92ve=20 actually taken to running the MP between 29-30=94 during the = winter time=20 just to keep Judy warm and happy. A good investment=85=20 <grin>     Just=20 a last bit of information to =93polish off=94 the system: The flow = of high=20 pressure air into the cockpit is =93unregulated=94 as long as the = dump control=20 is closed, and although relatively constant, is subject to changes = in both=20 pressure and flow rate depending on engine power setting. The = cockpit=20 pressure is maintained by controlling the outflow (controlled = leakage) of=20 air through the Dukes controller mounted in a =93bucket=94 under = the rear=20 seat. This is an electrically-controlled exhaust valve and takes = some time=20 to adjust to flow and pressure changes. It=92s therefore easy to = =93get ahead=94=20 of the pressurization system by rapidly changing the engine power = setting.=20 Most of us have learned to compensate for this, but if you=92re = getting a=20 lot of ear-popping and complaints from your passengers, try = changing the=20 engine power more gradually, especially at level-off and start of = descent.=20 =85And I=92m sure you=92ve all discovered by now what happens if = you pull the=20 engine back to below 25=94 MP or so while at altitude? The air in = the cabin=20 actually back-flows through the engine and the cabin altitude goes = quickly=20 to the outside pressure altitude. Solution: Keep the MP above = 25=94 until=20 you=92re down out of the flight levels; then slowly bring it back = more if=20 needed=85   Hope=20 this helps!   Bob
<= BR>
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