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		Dee One
 
 
  Joined: 29 Jun 2015 Posts: 48
 
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				 Posted: Sun Apr 03, 2016 12:25 pm    Post subject: Fuel Vapors in Cockpit | 
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				I had my maiden flight in my 2007 Allegro yesterday. One concern that I had was the smell of fuel particularly at low airspeed. My 17 gallon tank is in the fuselage under the seats. Has anyone else experienced this issue and if so what was your resolution? Also, would anyone happen to have a fuel system diagram showing feed lines, return lines, and vent lines . . . This may help to determine where are the vapors are originating from.  Thanks for your response.
 
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		hgmckay
 
 
  Joined: 23 May 2006 Posts: 397
 
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				 Posted: Mon Apr 04, 2016 6:40 am    Post subject: Fuel Vapors in Cockpit | 
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				Dee One,
 
 If you are smelling fuel, my first suggestion is "don't fly the plane until 
 you find the source of the fuel smell". You have too much at stake, your 
 life!!
 
 Is your airplane a new allegro that was manufactured by LSA America? If it 
 is call them and ask for help in finding the source of the fuel odor. If you 
 bought your plane as a used Allegro, I would still call them. Another 
 question is your Allegro a S-LSA or and E-LSA? If you have a S-LSA Allegro 
 you probably have only a limited amount of technical information, drawings, 
 diagrams, etc.. I fly an E-LSA Allegro 2000 model which I built from a Kit 
 and know intimately, and can only comment on that airplane (which is a 
 little different than an Allegro 2007 model). On the Allegro 2000 the 
 electric fuel pump is just in front of the main belly tank under the floor 
 board. Not sure where it is on the 2007 Model. Also, if you have wing tanks 
 the plumbing for the fuel lines is much more complex than with out wing 
 tanks.
 
 My first suggestion is to check the two fuel vent connections on the main 
 fuel tank under your seat. They should be located just inside the cockpit on 
 the very left side of the tank under the carpet covering.
 My second suggestion is to remove the top engine cowl and carefully inspect 
 ALL the fuel line connections to the mechanical fuel pump, the fuel 
 distributer (a five prong device that has five fuel lines connected to it) 
 located on the top of the engine, and all fuel lines down stream from the 
 fuel distributer. One of these downstream lines is a vent line back to the 
 main fuel tank, one goes to the fuel pressure gage on your instrument 
 panel(if you have a mechanical pressure gage), two go to the two carbs., and 
 the last is the line coming in from the engine fuel pump.
 
 My third suggestion is to find out where the electric fuel pump is located. 
 If it is under the floor board remove the floor board and check the fuel 
 line connections to the electric fuel pump and the fuel tank, and the 
 gascolator if it has one, and all other fuel line connections between the 
 gascolator and the engine fuel pump.
 
 Do these inspections in sequence and hopefully you will find the problem, 
 but by all means don't fly the plane until you find the source of fuel odor 
 and correct it.
 
 Hugh G. McKay III, P.E. Fellow, L.M. ASCE
 Senior Consultant
 Worldwide Engineering Inc.
 4090 North NC Hwy. 16
 Denver, NC 28037
 
 Ph. 704-661-8271
 Fax 704-483-5466
 email hgmckay(at)bellsouth.net
 http://www.wwegeo.com
 --
 
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		Dee One
 
 
  Joined: 29 Jun 2015 Posts: 48
 
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				 Posted: Mon Apr 04, 2016 12:51 pm    Post subject: Fuel Vapors in Cockpit | 
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				Hello Hugh, good to hear back from you. I have already completed all of the actions that you have suggested below. I have checked all the connections and they all look good. I have made a fuel system diagram and it is as you described below. The only anomaly that I found was fuel stains on the belly between the gascolater (which is in front of the firewall) and the fuel tank drain valve. The fumes may be coming from the gascolater and it may have a bad gasket. I will check into that. Thanks again. Dee LeBlanc
 Aerospace Engineer, AIAA
 Aero One Ltd
 leblancds(at)cox.net (leblancds(at)cox.net)
 cell 225-802-1038
 ~~~~~~~~~~~~~~~~
 The Past is History
 The Future is a Mystery
 Today is a Gift
 That’s Why They Call it the Present
  
  [quote]On Apr 4, 2016, at 9:40 AM, Hugh McKay <hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)> wrote:
 --> Allegro-List message posted by: "Hugh McKay" <hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)>Dee One,If you are smelling fuel, my first suggestion is "don't fly the plane until you find the source of the fuel smell". You have too much at stake, your life!!Is your airplane a new allegro that was manufactured by LSA America? If it is call them and ask for help in finding the source of the fuel odor. If you bought your plane as a used Allegro, I would still call them. Another question is your Allegro a S-LSA or and E-LSA? If you have a S-LSA Allegro you probably have only a limited amount of technical information, drawings, diagrams, etc.. I fly an E-LSA Allegro 2000 model which I built from a Kit and know intimately, and can only comment on that airplane (which is a little different than an Allegro 2007 model). On the Allegro 2000 the electric fuel pump is just in front of the main belly tank under the floor board. Not sure where it is on the 2007 Model. Also, if you have wing tanks the plumbing for the fuel lines is much more complex than with out wing tanks.My first suggestion is to check the two fuel vent connections on the main fuel tank under your seat. They should be located just inside the cockpit on the very left side of the tank under the carpet covering.My second suggestion is to remove the top engine cowl and carefully inspect ALL the fuel line connections to the mechanical fuel pump, the fuel distributer (a five prong device that has five fuel lines connected to it) located on the top of the engine, and all fuel lines down stream from the fuel distributer. One of these downstream lines is a vent line back to the main fuel tank, one goes to the fuel pressure gage on your instrument panel(if you have a mechanical pressure gage), two go to the two carbs., and the last is the line coming in from the engine fuel pump.My third suggestion is to find out where the electric fuel pump is located. If it is under the floor board remove the floor board and check the fuel line connections to the electric fuel pump and the fuel tank, and the gascolator if it has one, and all other fuel line connections between the gascolator and the engine fuel pump.Do these inspections in sequence and hopefully you will find the problem, but by all means don't fly the plane until you find the source of fuel odor and correct it.Hugh G. McKay III, P.E. Fellow, L.M. ASCESenior ConsultantWorldwide Engineering Inc.4090 North NC Hwy. 16Denver, NC 28037Ph. 704-661-8271Fax 704-483-5466email hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)http://www.wwegeo.com--
 
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  http://www.matronics.com/Navigator?Allegro-List |  
  |  
 
 
 
 
  _________________ The Past is History
 
The Future is a Mystery
 
Today is a Gift
 
That’s Why They Call it the Present | 
			 
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		hgmckay
 
 
  Joined: 23 May 2006 Posts: 397
 
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				 Posted: Mon Apr 04, 2016 3:43 pm    Post subject: Fuel Vapors in Cockpit | 
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				Dee,
   
  If all other fuel connections are good the problem may very well be at the  gascolater, especially if there are fuel stains on the underside of the  airplane’s belly. If the gascolater has never been opened it may have a bad  gasket to begin with, or if it has been opened to check for contaminated fuel  and bulb re-set; the gasket could be pinched, or the bulb not seated properly on  the gasket before tightening. Another possibility is that the bulb itself is  cracked due to over tightening. Either of these could cause a small fuel lake at  the gascolater which because if its location would allow fumes to come up inside  the cockpit under the floor board when taxiing (low engine rpms and very low air  speed. speeds. It is going to be hard to determine if the bulb gasket is damaged  because of its location, but you can check the integrity of the bulb by simply  removing it and carefully inspecting it. I would check the bulb first. If it is  not damaged (cracked), then carefully inspect the gasket seat in the bulb  housing using a bright light. Of course before you do this you will have to  drain all the fuel!
   
  Hugh G. McKay III, P.E. Fellow, L.M. ASCE
 Senior Consultant
 Worldwide  Engineering Inc.
 4090 North NC Hwy. 16
 Denver, NC 28037
 
 Ph.  704-661-8271
 Fax 704-483-5466
 email  hgmckay(at)bellsouth.net
 http://www.wwegeo.com
     
   From: Dee LeBlanc (leblancds(at)cox.net) 
  Sent: Monday, April 04, 2016 4:51 PM
  To: allegro-list(at)matronics.com (allegro-list(at)matronics.com) 
  Subject: Re: Fuel Vapors in Cockpit
   
 
  Hello  Hugh, good to hear back from you. I have already completed all of the actions  that you have suggested below. I have checked all the connections and they all  look good. I have made a fuel system diagram and it is as you described below.  The only anomaly that I found was fuel stains on the belly between the  gascolater (which is in front of the firewall) and the fuel tank drain valve.  The fumes may be coming from the gascolater and it may have a bad gasket. I will  check into that. Thanks again.    
      Dee LeBlanc
  Aerospace Engineer, AIAA
  Aero One Ltd
  leblancds(at)cox.net (leblancds(at)cox.net)
  cell 225-802-1038
   ~~~~~~~~~~~~~~~~
  The Past is History
  The Future is a Mystery
  Today is a Gift
  That’s Why They Call it the  Present
 
  
 
   
 
   
 
   
   
    	  | Quote: | 	 		     On Apr 4, 2016, at 9:40 AM, Hugh McKay <hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)> wrote:
     
    --> Allegro-List message posted by: "Hugh McKay" <hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)>
 
 Dee    One,
 
 If you are smelling fuel, my first suggestion is "don't fly the    plane until you find the source of the fuel smell". You have too much at    stake, your life!!
 
 Is your airplane a new allegro that was manufactured    by LSA America? If it is call them and ask for help in finding the source of    the fuel odor. If you bought your plane as a used Allegro, I would still call    them. Another question is your Allegro a S-LSA or and E-LSA? If you have a    S-LSA Allegro you probably have only a limited amount of technical    information, drawings, diagrams, etc.. I fly an E-LSA Allegro 2000 model which    I built from a Kit and know intimately, and can only comment on that airplane    (which is a little different than an Allegro 2007 model). On the Allegro 2000    the electric fuel pump is just in front of the main belly tank under the floor    board. Not sure where it is on the 2007 Model. Also, if you have wing tanks    the plumbing for the fuel lines is much more complex than with out wing    tanks.
 
 My first suggestion is to check the two fuel vent connections on    the main fuel tank under your seat. They should be located just inside the    cockpit on the very left side of the tank under the carpet covering.
 My    second suggestion is to remove the top engine cowl and carefully inspect ALL    the fuel line connections to the mechanical fuel pump, the fuel distributer (a    five prong device that has five fuel lines connected to it) located on the top    of the engine, and all fuel lines down stream from the fuel distributer. One    of these downstream lines is a vent line back to the main fuel tank, one goes    to the fuel pressure gage on your instrument panel(if you have a mechanical    pressure gage), two go to the two carbs., and the last is the line coming in    from the engine fuel pump.
 
 My third suggestion is to find out where the    electric fuel pump is located. If it is under the floor board remove the floor    board and check the fuel line connections to the electric fuel pump and the    fuel tank, and the gascolator if it has one, and all other fuel line    connections between the gascolator and the engine fuel pump.
 
 Do these    inspections in sequence and hopefully you will find the problem, but by all    means don't fly the plane until you find the source of fuel odor and correct    it.
 
 Hugh G. McKay III, P.E. Fellow, L.M. ASCE
 Senior    Consultant
 Worldwide Engineering Inc.
 4090 North NC Hwy. 16
 Denver,    NC 28037
 
 Ph. 704-661-8271
 Fax 704-483-5466
 email hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)
 http://www.wwegeo.com
 -----Original    Message----- From: Dee One
 Sent: Sunday, April 03, 2016 4:25 PM
 To:    allegro-list(at)matronics.com
 Subject: Fuel Vapors in    Cockpit
 
 --> Allegro-List message posted by: "Dee One"    <leblancds(at)cox.net>
 
 I had my maiden flight in my 2007 Allegro    yesterday. One concern that I had was the smell of fuel particularly at low    airspeed. My 17 gallon tank is in the fuselage under the seats. Has anyone    else experienced this issue and if so what was your resolution? Also, would    anyone happen to have a fuel system diagram showing feed lines, return lines,    and vent lines . . . This may help to determine where are the vapors are    originating from.  Thanks for your response.
 
 --------
 The Past    is History
 The Future is a Mystery
 Today is a Gift
 That’s Why They    Call it the Present
 
 
 Read this topic online    here:
 
 http://forums.matronics.com/viewtopic.php?p=454512#454512
 
 
 
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  http://www.matronics.com/Navigator?Allegro-List |  
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		Dee One
 
 
  Joined: 29 Jun 2015 Posts: 48
 
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				 Posted: Mon Apr 04, 2016 3:59 pm    Post subject: Fuel Vapors in Cockpit | 
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				OK Hugh, Will pursue this avenue. Thanks for your advice.
 Dee
 
 
  
   	  | Quote: | 	 		  On Apr 4, 2016, at 6:43 PM, Hugh McKay <hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)> wrote:
      Dee,
   
  If all other fuel connections are good the problem may very well be at the  gascolater, especially if there are fuel stains on the underside of the  airplane’s belly. If the gascolater has never been opened it may have a bad  gasket to begin with, or if it has been opened to check for contaminated fuel  and bulb re-set; the gasket could be pinched, or the bulb not seated properly on  the gasket before tightening. Another possibility is that the bulb itself is  cracked due to over tightening. Either of these could cause a small fuel lake at  the gascolater which because if its location would allow fumes to come up inside  the cockpit under the floor board when taxiing (low engine rpms and very low air  speed. speeds. It is going to be hard to determine if the bulb gasket is damaged  because of its location, but you can check the integrity of the bulb by simply  removing it and carefully inspecting it. I would check the bulb first. If it is  not damaged (cracked), then carefully inspect the gasket seat in the bulb  housing using a bright light. Of course before you do this you will have to  drain all the fuel!
   
  Hugh G. McKay III, P.E. Fellow, L.M. ASCESenior ConsultantWorldwide  Engineering Inc.4090 North NC Hwy. 16Denver, NC 28037Ph.  704-661-8271Fax 704-483-5466email  hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)http://www.wwegeo.com
     
   From: Dee LeBlanc (leblancds(at)cox.net) 
  Sent: Monday, April 04, 2016 4:51 PM
  To: allegro-list(at)matronics.com (allegro-list(at)matronics.com) 
  Subject: Re: Fuel Vapors in Cockpit
   
 
  Hello  Hugh, good to hear back from you. I have already completed all of the actions  that you have suggested below. I have checked all the connections and they all  look good. I have made a fuel system diagram and it is as you described below.  The only anomaly that I found was fuel stains on the belly between the  gascolater (which is in front of the firewall) and the fuel tank drain valve.  The fumes may be coming from the gascolater and it may have a bad gasket. I will  check into that. Thanks again.    
      Dee LeBlanc
  Aerospace Engineer, AIAA
  Aero One Ltd
  leblancds(at)cox.net (leblancds(at)cox.net)
  cell 225-802-1038
   ~~~~~~~~~~~~~~~~
  The Past is History
  The Future is a Mystery
  Today is a Gift
  That’s Why They Call it the  Present
 
  
   
 
   
 
   
   
    	  | Quote: | 	 		     On Apr 4, 2016, at 9:40 AM, Hugh McKay <hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)> wrote:
     
    --> Allegro-List message posted by: "Hugh McKay" <hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)>Dee    One,If you are smelling fuel, my first suggestion is "don't fly the    plane until you find the source of the fuel smell". You have too much at    stake, your life!!Is your airplane a new allegro that was manufactured    by LSA America? If it is call them and ask for help in finding the source of    the fuel odor. If you bought your plane as a used Allegro, I would still call    them. Another question is your Allegro a S-LSA or and E-LSA? If you have a    S-LSA Allegro you probably have only a limited amount of technical    information, drawings, diagrams, etc.. I fly an E-LSA Allegro 2000 model which    I built from a Kit and know intimately, and can only comment on that airplane    (which is a little different than an Allegro 2007 model). On the Allegro 2000    the electric fuel pump is just in front of the main belly tank under the floor    board. Not sure where it is on the 2007 Model. Also, if you have wing tanks    the plumbing for the fuel lines is much more complex than with out wing    tanks.My first suggestion is to check the two fuel vent connections on    the main fuel tank under your seat. They should be located just inside the    cockpit on the very left side of the tank under the carpet covering.My    second suggestion is to remove the top engine cowl and carefully inspect ALL    the fuel line connections to the mechanical fuel pump, the fuel distributer (a    five prong device that has five fuel lines connected to it) located on the top    of the engine, and all fuel lines down stream from the fuel distributer. One    of these downstream lines is a vent line back to the main fuel tank, one goes    to the fuel pressure gage on your instrument panel(if you have a mechanical    pressure gage), two go to the two carbs., and the last is the line coming in    from the engine fuel pump.My third suggestion is to find out where the    electric fuel pump is located. If it is under the floor board remove the floor    board and check the fuel line connections to the electric fuel pump and the    fuel tank, and the gascolator if it has one, and all other fuel line    connections between the gascolator and the engine fuel pump.Do these    inspections in sequence and hopefully you will find the problem, but by all    means don't fly the plane until you find the source of fuel odor and correct    it.Hugh G. McKay III, P.E. Fellow, L.M. ASCESenior    ConsultantWorldwide Engineering Inc.4090 North NC Hwy. 16Denver,    NC 28037Ph. 704-661-8271Fax 704-483-5466email hgmckay(at)bellsouth.net (hgmckay(at)bellsouth.net)allegro-list(at)matronics.com (allegro-list(at)matronics.com)Subject: Fuel Vapors in    Cockpit--> Allegro-List message posted by: "Dee One"    <leblancds(at)cox.net (leblancds(at)cox.net)>I had my maiden flight in my 2007 Allegro    yesterday. One concern that I had was the smell of fuel particularly at low    airspeed. My 17 gallon tank is in the fuselage under the seats. Has anyone    else experienced this issue and if so what was your resolution? Also, would    anyone happen to have a fuel system diagram showing feed lines, return lines,    and vent lines . . . This may help to determine where are the vapors are    originating from.  Thanks for your response.--------The Past    is HistoryThe Future is a MysteryToday is a GiftThat’s Why They    Call it the PresentRead this topic online    here:http://forums.matronics.com/viewtopic.php?p=454512#454512
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  |  | - The Matronics Allegro-List Email Forum - |  |   |  Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
 
  http://www.matronics.com/Navigator?Allegro-List |  
  |  
 
 
 
 
  _________________ The Past is History
 
The Future is a Mystery
 
Today is a Gift
 
That’s Why They Call it the Present | 
			 
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		aerosiam
 
 
  Joined: 26 May 2008 Posts: 59
 
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				 Posted: Thu Apr 07, 2016 4:32 am    Post subject: Re: Fuel Vapors in Cockpit | 
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				Dee, do you have wing tanks ?
 
 I had a problem of fuel vapour smells but only on the climb out. The translucent small fuel overflow / vent lines from the wing tanks were the problem. The original connections and Tees looked ok but they leaked. If I remember correctely, the hoses didn't quite fit over the barbs and the material was soft. I changed them all and the problem went away.
 
 Regards
 Paul
 
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