Return-Path: Received: from [65.54.169.167] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2637913 for flyrotary@lancaironline.net; Wed, 15 Oct 2003 12:37:20 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 15 Oct 2003 09:37:20 -0700 Received: from 65.137.50.200 by bay3-dav137.bay3.hotmail.com with DAV; Wed, 15 Oct 2003 16:37:19 +0000 X-Originating-IP: [65.137.50.200] X-Originating-Email: [lors01@msn.com] Reply-To: "Tracy Crook" From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EWP - series pumps and wacky ideas Date: Wed, 15 Oct 2003 12:39:52 -0400 Organization: Real World Solutions Inc. MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0078_01C39319.6DD5CEE0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Message-ID: X-OriginalArrivalTime: 15 Oct 2003 16:37:20.0074 (UTC) FILETIME=[9A302AA0:01C3933A] This is a multi-part message in MIME format. ------=_NextPart_000_0078_01C39319.6DD5CEE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sorry for not snipping original msg more but needed this much to = maintain thought continuity. =20 Just as a data point, I will retell my experience with coolant = circulation loss. Due to a malfunctioning pressure cap I lost about 3-4 quarts of coolant = on a flight back from an RV fly-in in Texas. I was only about 10 = minutes into the flight when this occurred. No temperature clue to the = coolant loss until it got below waterpump level. Temp went from normal = to redline in SECONDS. There was an indication that something was wrong = on the coolant pressure gauge which read only 2-3 psi , which I chose to = ignore. I was keen to get home. (stupid - stupid - Stupid!) I immediately reduced power and hit goto nearest on GPS when the alarm = went off and was about 8 miles from nearest. Altitude was 3700 ft AGL. = Temperature stabilized at around 255 degrees but that may have been the = upper limit of the GRT EIS. Declared emergency and made a straight in = approach & landing. Engine continued to run normally throughout landing = & taxi. Obvious hot coolant smell when I shut down & got out to see the = damage. When I found the cap seal problem (& fixed) I let engine cool and = topped off the system with water. Coolant pressure returned to normal = and rest of flight home was normal. I'm still flying this same engine = which shows no ill effects from the incident. Here is the significant thing that I got out of this. After the coolant = loss below pump level, the temperature was held to a "safe" temp by the = remaining coolant in block being boiled off. Conventional wisdom says = that best place for waterpump is low point in the system but in this = scenario it may have resulted in pumping the remaining coolant out of = the system instead of leaving it in the block to cool the engine from = latent heat of steam. I credit this factor with saving the engine. Just something to think about when positioning those EWPs! Tracy ----- Original Message -----=20 From: Jim Sower=20 Rusty,=20 I can see your point. My ideas were motivated by my ambivalence = around running both pumps all the time (I'm uncomfortable with that for = reasons that I can't support really well) and the backup switch that = turns on the standby pump in the event of main pump failure (that's an = unknown quantity to me as far as reliability goes). I was looking to = examine as many failure modes as possible. Of course, as just occurred = to me, the backup pump switch would be exactly as reliable as the = overtemp alarm, since they'd both be driven by identical (if not the = same) detection device.=20 You're right in saying that we both have to make our own estimates of = the unknown consequences of various failures, and you're the man in the = driver's seat here. Keep up the good work. Your research is going to = relieve me of that chore. Don't think I don't appreciate that.=20 Russell Duffy wrote:=20 If it was me, I'd do a little testing - start at cruise at altitude = - and shut off the pump and see what happens and how fast.=20 I'll just have to wait and see how it works for you, because there's = no way I'm doing it. I think you're closer to underestimating the = damage, than I am to overestimating it, and if I have to be wrong, I'd = much rather be on the safe side.=20 ------=_NextPart_000_0078_01C39319.6DD5CEE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Sorry for not snipping original msg = more but needed=20 this much to maintain thought  continuity.    =
Just as a data point,  I will = retell my=20 experience with coolant circulation loss.
 
Due to a malfunctioning pressure = cap I lost=20 about 3-4 quarts of coolant on a flight back from an RV fly-in in = Texas.  I=20 was only about 10 minutes into the flight when this occurred.  No=20 temperature clue to the coolant loss  until it got below waterpump=20 level.  Temp went from normal to redline in SECONDS.  There = was an=20 indication that something was wrong on the coolant pressure gauge which = read=20 only 2-3 psi , which I chose to ignore.  I was keen to get = home. =20  (stupid - stupid - Stupid!)
 
I immediately reduced power and = hit goto=20 nearest on GPS when the alarm went off and was about 8 miles = from=20 nearest.  Altitude was 3700 ft AGL.   Temperature = stabilized at=20 around 255 degrees but that may have been the upper limit of the GRT = EIS. =20 Declared emergency and made a straight in approach & landing.  = Engine=20 continued to run normally throughout landing & taxi.  Obvious = hot=20 coolant smell when I shut down & got out to see the = damage.
 
When I found the cap seal problem = (& fixed)=20  I let engine cool and topped off the system with water.  = Coolant=20 pressure returned to normal and rest of flight home was = normal.   I'm=20 still flying this same engine which shows no ill effects from the=20 incident.
 
Here is the significant thing that I = got out of=20 this.  After the coolant loss below pump level,  the = temperature was=20 held to a "safe" temp by the remaining coolant in block being boiled=20 off.   Conventional wisdom says that best place for waterpump = is low=20 point in the system but in this scenario it may have resulted=20 in pumping the remaining coolant out of the system instead of = leaving it in=20 the block to cool the engine from latent heat of steam.  I credit = this=20 factor with saving the engine.
 
Just something to think about when = positioning=20 those EWPs!
 
Tracy
----- Original Message -----
From:=20 Jim=20 Sower
 
Rusty,
I can see your=20 point.  My ideas were motivated by my ambivalence around running = both=20 pumps all the time (I'm uncomfortable with that for reasons that I = can't=20 support really well) and the backup switch that turns on the standby = pump in=20 the event of main pump failure (that's an unknown quantity to me as = far as=20 reliability goes).  I was looking to examine as many failure = modes as=20 possible.  Of course, as just occurred to me, the backup pump = switch=20 would be exactly as reliable as the overtemp alarm, since they'd both = be=20 driven by identical (if not the same) detection device.=20

You're right in saying that we both have to make our own estimates = of the=20 unknown consequences of various failures, and you're the man in the = driver's=20 seat here.  Keep up the good work.  Your research is going = to=20 relieve me of that chore.  Don't think I don't appreciate that.=20

Russell Duffy wrote:=20

If it was me, I'd do a little testing - start at = cruise at=20 altitude - and shut off the pump and see what happens and how = fast.=20

I'll just have to wait = and see how=20 it works for you, because there's no way I'm doing it.  I think = you're=20 closer to underestimating the damage, than I am to overestimating = it, and if=20 I have to be wrong, I'd much rather be on the safe = side.=20

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