X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from sccrmhc14.comcast.net ([63.240.77.84] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2084053 for flyrotary@lancaironline.net; Mon, 04 Jun 2007 18:57:29 -0400 Received-SPF: none receiver=logan.com; client-ip=63.240.77.84; envelope-from=wschertz@comcast.net Received: from wschertzpc (c-24-7-194-231.hsd1.il.comcast.net[24.7.194.231]) by comcast.net (sccrmhc14) with SMTP id <2007060422565301400de7l7e>; Mon, 4 Jun 2007 22:56:53 +0000 Message-ID: <93EAFA9A602646549A56954BF6933067@WschertzPC> From: "Bill Schertz" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: EC-2/EM-2 manifold pressure Date: Mon, 4 Jun 2007 17:56:51 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002E_01C7A6D1.BAF543C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16386 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16386 This is a multi-part message in MIME format. ------=_NextPart_000_002E_01C7A6D1.BAF543C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Al and TJ, I makes more sense now, ignore my message just sent a few minutes ago. Bill Schertz KIS Cruiser #4045 ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Monday, June 04, 2007 12:23 PM Subject: [FlyRotary] Re: EC-2/EM-2 manifold pressure Well Bill, if the Kolsman window is where you set your altimeter setting (mb or = inches mercury) you will never see field elevation (pressure) unless you = are at sealevel. E.g. if you have 29.92" at sealevel (and in the window) you still have = 29.92 in the window (you set it there!) when you get to 6500'. Your = actual ambient pressure is around 23.42".... (which you should be = reading on your manifold pressure gauge - engine stopped...=20 Unless, I got it wrong the last 15 years and 9500 hours - ohhh my...!! TJ I think you've got it right. It seems to me that if you want to find = what your MAP out to be when parked, engine off; you set 29.92 in the = altimeter window to get pressure altitude, then either use a formula or = chart to get the expected air pressure at that altitude. For example, = if you set 29.92 and it shows your pressure altitude to be 2000 ft, then = your chart will tell you that the air pressure where you are is 27.8 in. = HG for a standard day, then correct for temp. So unless I'm mistaken, that is the same as calling the tower (or = weather observation station, or get out your handy-dandy flight = computer) and get the density altitude, then vary the altimeter setting = until the altitude reads density altitude, and get the pressure from the = Kolsman window. Al ------=_NextPart_000_002E_01C7A6D1.BAF543C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks Al and TJ,
I makes more sense now, ignore my = message just sent=20 a few minutes ago.
 
Bill Schertz
KIS Cruiser #4045
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Monday, June 04, 2007 = 12:23=20 PM
Subject: [FlyRotary] Re: = EC-2/EM-2=20 manifold pressure

Well = Bill,

if the Kolsman window is = where you set=20 your altimeter setting (mb or inches mercury) you will never see field = elevation (pressure) unless you are at = sealevel.

 

E.g. if you have 29.92" at = sealevel (and=20 in the window) you still have 29.92 in the window (you set it there!)=20 when  you get to 6500'. Your actual ambient pressure is around = 23.42"....=20 (which you should be reading on your manifold pressure gauge - engine=20 stopped...

 

Unless, I got it wrong the = last 15 years=20 and 9500 hours - ohhh my...!!

 TJ

I think = you=92ve got=20 it right.  It seems to me that if you want to find what your MAP = out to=20 be when parked, engine off; you set 29.92 in the altimeter window to = get=20 pressure altitude, then either use a formula or chart to get the = expected air=20 pressure at that altitude.  For example, if you set 29.92 and it = shows=20 your pressure altitude to be 2000 ft, then your chart will tell you = that the=20 air pressure where you are is 27.8 in. HG for a standard day, then = correct for=20 temp.

 

So unless = I=92m=20 mistaken, that is the same as = calling the=20 tower (or weather observation station, or get out your handy-dandy = flight=20 computer) and get the density altitude, then vary the altimeter = setting until=20 the altitude reads density altitude, and get the pressure from the = Kolsman=20 window.

 

Al

 

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