X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 01 Oct 2007 12:09:23 -0400 Message-ID: X-Original-Return-Path: Received: from web62510.mail.re1.yahoo.com ([69.147.75.102] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with SMTP id 2361980 for lml@lancaironline.net; Mon, 01 Oct 2007 09:29:22 -0400 Received-SPF: none receiver=logan.com; client-ip=69.147.75.102; envelope-from=charliekohler@yahoo.com Received: (qmail 90109 invoked by uid 60001); 1 Oct 2007 13:28:43 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Received:X-Mailer:Date:From:Subject:To:MIME-Version:Content-Type:Message-ID; b=gBvM4dzeaW6KsQ+XfPte9ugjG1KzBzG2uk0DXcGn5zk3FC+JHuRLaIl1sv7g5GvXfq/4LN6q/xwpfQ5Jul7wvEG0tlML4WmBdeHLr08fhFQ/6elvhC7d3co2+Ycag7P+FcTVjzdgcwUI1IOmrjf6vJvqWYH1rPDw/AuatmjrZqo=; Received: from [206.190.53.136] by web62510.mail.re1.yahoo.com via HTTP; Mon, 01 Oct 2007 06:28:43 PDT X-Mailer: YahooMailRC/651.50 YahooMailWebService/0.7.134 X-Original-Date: Mon, 1 Oct 2007 06:28:43 -0700 (PDT) From: Charlie Kohler Subject: Gascolators X-Original-To: LancairList MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1622537444-1191245323=:89930" X-Original-Message-ID: <686738.89930.qm@web62510.mail.re1.yahoo.com> --0-1622537444-1191245323=:89930 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi Craig,=0AJust a few last comments on this thread.=0ABy your description = of your filter, you have what I believe it would be best called a filter by= pass feature rather than a pressure relief valve. I think we both agree why= this is necessary. If you were to plug the filter with contaminants it wou= ld be best to keep the engine running to return to the airport. Even at the= expense of putting contaminants in the whole system.=0AThe other reg that = I did not display talks about quantity. It uses terms like "sediment bowl" = which would indicate that be at has the capacity of trapping a "volume" of = contaminants. The bypass filter that you have is not designed to trap and h= old any contaminants.When the quantity of contaminates cover the surface of= the filter to the degree that the pressure differential overcomes spring p= ressure-- it bypasses.=0AThe reg 23.971 talks about a quantity that the sed= iment bowl (gascolator) is able to hold. Is that important? I think so.=0AI= mentioned that I had seen water and even mud in gascolator's in my years o= f flying experience. These cases were mostly all around ferry flights where= airplanes had been stored for long periods due to death/incapacitation of = the owner etc. etc.. Some of these airplanes were stored outside for a whil= e. After shaking the wings-- draining the sumps until clear, I still was th= ankful for a sediment bowl to trap the remaining contaminated contents. =0A= Your comment about observing "43 gal per hour to 42" and noting that change= as a indicator that the filter is becoming plugged, is not practical in my= opinion.. Variations in altitude, temperature, rpm and manifold pressure a= nd indicators would make this impractical.=0AThe engine-driven fuel pump wi= ll compensate (up to a point) for the partial plugging of a filter up strea= m-- and therefore mask that restriction. =0AYou're right, that it is one of= those "personal decisions", (isn't amateur building great!). However, "not= so good left over's from a long time ago" is not true, in my judgement. An= d the noose is tightening with the requirement of insurance inspections, an= d one of the issues that they are extremely concerned about is "modificatio= ns" such as this.=0A =0ASection 23.971: Fuel tank sump.=0A(c) Each reciproc= ating engine fuel system must have a sediment bowl or chamber that is acces= sible for drainage; has a capacity of 1 ounce for every 20 gallons of fuel = tank capacity; and each fuel tank outlet is located so that, in the normal = flight attitude, water will drain from all parts of the tank except the sum= p to the sediment bowl or chamber.=0A(d) Each sump, sediment bowl, and sedi= ment chamber drain required by paragraphs (a), (b), and (c) of this section= must comply with the drain provisions of =A723.999 =0A=0A =0ACharlie K. = =0A =0A =0ACharlie, my fuel filter has an internal pressure relief to preve= nt a plugged filter from stopping fuel flow. I think this plugged fuel fil= ter condition can be prevented through normal maintenance by monitoring tak= e off fuel rate. If fuel rate drops from 43 gal per hr to 42 then checking= the filter is in order. I will need to pull the top cowl, but cleaning th= e filter is a piece of cake after that. I also have the stock high pressure= overboard relief.=0A =0AI have had others say they have found stuff in a g= ascolator as well. I have been a "poor" flyer for 20 plus years flying 40 = year old planes that set on the tarmac all day and night. I have seen wate= r and particles in the tank drains many times, but NEVER in the gascolator.= =0A =0AThe Bonanza has two perfectly good drains, one in each wing. Since= it is a low wing, it must meet the requirements of FAR 23.999. I can't sa= y for sure as I'm not up on all the far's, but it passes annuals.=0A =0AI t= hink the gascolator is one of those "personal" decisions, but in my opinion= the design is one of those not so good left over's from a long time ago an= d the low volumes of general aviation won't pay for an upgrade. While our = constant flow injectors are not nearly as sensitive as the automotive elect= ronic injectors, I still believe a fuel filter is important and a necessity= . That is the main point I wanted to make. Specifically, I feel a filter = is a positive rather than a hindrance. The FAA obviously disagrees with me= as well.=0ACraig Berland --0-1622537444-1191245323=:89930 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
=0A
=0A

Hi C= raig,

=0A

Just a few last comments on this threa= d.

=0A

By your description of your filter, you h= ave what I believe it would be best called a filter bypass feature rather t= han a pressure relief valve. I think we both agree why this is necessary. I= f you were to plug the filter with contaminants it would be best to keep th= e engine running to return to the airport. Even at the expense of putting c= ontaminants in the whole system.

=0A

The other r= eg that I did not display talks about quantity. It uses terms like "sedimen= t bowl" which would indicate that be at has the capacity of trapping a "vol= ume" of contaminants. The bypass filter that you have is not designed to tr= ap and hold any contaminants.When the quantity of contaminates cover the su= rface of the filter to the degree that the pressure differential overcomes = spring pressure-- it bypasses.

=0A

The reg 23.97= 1 talks about a quantity that the sediment bowl (gascolator) is able to hol= d. Is that important? I think so.

=0A

I mentione= d that I had seen water and even mud in gascolator's in my years of flying = experience. These cases were mostly all around ferry flights where airplane= s had been stored for long periods due to death/incapacitation of the owner= etc. etc.. Some of these airplanes were stored outside for a while. After = shaking the wings-- draining the sumps until clear, I still was thankful fo= r a sediment bowl to trap the remaining contaminated contents.

= =0A

Your comment about observing "43 gal per hour to 42" a= nd noting that change as a indicator that the filter is becoming plugged, i= s not practical in my opinion.. Variations in altitude, temperature, r= pm and manifold pressure and indicators would make this impractical.=

=0A

The engine-driven fuel pump will compensate (up to= a point) for the partial plugging of a filter up stream-- and therefore ma= sk that restriction.

=0A

You're right, that it = is one of those "personal decisions", (isn't amateur building great!). Howe= ver, "not so good left over's f= rom a long time ago" is not true, in my judgement. And the noose is tighten= ing with the requirement of insurance inspections, and one of the issues th= at they are extremely concerned about is "modifications" such as this.=

=0A

 

=0A

Section 23.971: Fuel tank sump.<= /P>=0A

(c) Each reciprocating engine fuel system must = have a sediment bowl or chamber that is accessible for drainage; has a capa= city of 1 ounce for every 20 gallons of fuel tank capacity; and each fuel t= ank outlet is located so that, in the normal flight attitude, water will dr= ain from all parts of the tank except the sump to the sediment bowl or cham= ber.

=0A

(d) Each sump, sediment bowl, and sedim= ent chamber drain required by paragraphs (a), (b), and (c) of this section = must comply with the drain provisions of =A723.999


 
Charlie K. =0A
=0A
 
=0A
 <= /DIV>=0A
Charlie, my fuel filter has= an internal pressure relief to prevent a plugged filter from stopping= fuel flow.  I think this plugged fuel filter condition can be prevent= ed through normal maintenance by monitoring take off fuel rate.  = If fuel rate drops from 43 gal per hr to 42 then checking the filter i= s in order.  I will need to pull the top cowl, but cleaning the filter= is a piece of cake after that. I also have the stock high pressure overboa= rd relief.
=0A
 
=0A
I have had others say they h= ave found stuff in a gascolator as well.  I have been a "poor" fl= yer for 20 plus years flying 40 year old planes that set on the tarmac all = day and night.  I have seen water and particles in the tank drain= s many times, but NEVER in the gascolator. 
= =0A
 
=0A
The Bonanza has two perfectly good drains, one in each = wing.  Since it is a low wing, it must meet the requirements of FAR 23= .999.  I can't say for sure as I'm not up on all the far's, but it pas= ses annuals.
=0A
 
=0A
I think the gascolator is= one of those "personal" decisions, but in my opinion the design is one of = those not so good left over's from a long time ago and the low volumes of g= eneral aviation won't pay for an upgrade.  While our constant flow inj= ectors are not nearly as sensitive as the automotive electronic injectors, = I still believe a fuel filter is important and a necessity.  That= is the main point I wanted to make.  Specifically, I feel a filter&nb= sp;is a positive rather than a hindrance.  The FAA obviously disa= grees with me as well.
=0A
= Craig Berland
=0A
 
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