X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao103.cox.net ([68.230.241.43] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4165061 for flyrotary@lancaironline.net; Sat, 13 Mar 2010 23:39:12 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.43; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao103.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100314043837.UEVO19579.fed1rmmtao103.cox.net@fed1rmimpo01.cox.net> for ; Sat, 13 Mar 2010 23:38:37 -0500 Received: from willsPC ([68.105.86.80]) by fed1rmimpo01.cox.net with bizsmtp id sseF1d0061k005Q03seFew; Sat, 13 Mar 2010 23:38:15 -0500 X-VR-Score: -30.00 X-Authority-Analysis: v=1.1 cv=qY0/QvRffkjURHWZjC3q+nTs9PdPIIJxYa32KydkvE8= c=1 sm=1 a=GkVrOFAuG9wA:10 a=XruvlouZCDbGUgEaRUiNZQ==:17 a=Ia-xEzejAAAA:8 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=3oc9M9_CAAAA:8 a=nUuTZ29dAAAA:8 a=u4QCNQnftk8yc9rhKeUA:9 a=3MugSsS1VZ7ySFeVuogA:7 a=9_yIYb0tpB3oZTMq3u6-dD3Mc30A:4 a=wPNLvfGTeEIA:10 a=1vhyWl4Y8LcA:10 a=EzXvWhQp4_cA:10 a=U8Ie8EnqySEA:10 a=dBDylTs6leMON6re:21 a=c3UGQ5InEOHSzwP7:21 a=pedpZTtsAAAA:8 a=rd-O8JD0pGSPjtgRf_AA:9 a=vSYiVLmimGeujsVKfjcA:7 a=RSJnXhRhOs5ikCZfjUQ9MV_PNykA:4 a=eJojReuL3h0A:10 a=P7vQMHKEp9kTx9oj:21 a=Bsm7PC6kBdtlXLHl:21 a=XruvlouZCDbGUgEaRUiNZQ==:117 X-CM-Score: 0.00 Message-ID: <39DC6DDAE4C7431D878C100ACA638CCF@willsPC> From: "Mike Wills" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: fuel supply problem? Date: Sat, 13 Mar 2010 20:38:14 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0054_01CAC2ED.1ABA38D0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_0054_01CAC2ED.1ABA38D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Bill, My day got side tracked and I didn't get a chance to check it out today. = My RV-4 holds 15.5 gallons per side (Vans says 32 total). The EFISM says = there is 11 gallons left in the airplane and both the quantity gauges = and my eyes say that the left tank (which was the problem tank) now = actually has a little more fuel in it than the right tank which I flew = home and landed on. The EFISM has proven to be pretty accurate so far. I = havent had it all that long but it has never been off by more than a = gallon. But the real answer wont be known until I fill the tanks, = hopefully tomorrow. So in my RV, 5 gallons left in each tank would represent almost a third = of the total fuel available. If I assume only 21 gallons useable. That = would be pretty unsatisfactory. And not at all consistent with my 150 = hours of previous experience with my old RV-6A which has an almost = identical fuel tank setup (total of 36 gallons vs 32). Not sure what airplane you fly but the RVs have significant dihedral. No = memorable turbulence at the time the problem happened. When I took off = the EFISM said I had 27 gallons. The right tank was completely full, the = left tank was down 4 gallons from full (if the EFISM can be believed). = My first 50 minutes of flight were on the full right tank. I switched to = left just before landing at Borrego to have something to drink. Then = departed on the left tank. The problem happened at around 1.3 - 1.5 = hours so maybe 30 - 40 minutes of flight time plus one takeoff and climb = on the left tank when the problem occurred. Mike From: Bill Bradburry=20 Sent: Saturday, March 13, 2010 12:58 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: fuel supply problem? Hi Mike, Have you removed and measured how much fuel was actually in the tanks? = What did your fuel gages say at the time? What is your tank capacity? = Each wing on my plane holds 33 gal, so getting down to 5 gal with very = little dihedral in the wings, means I am pretty low on fuel. 1/8 tank = in fact. The way I calibrated my gage was to drain the tank dry, add = one gallon, calibrated this to be Zero, then added 4 gal and calibrated = this to be 1/8, and then each 4 gal was another eighth, etc. I think it = would be very easy to unport my tanks with only 5 gal in them. With the = plane sitting level on the ground, it will drain the tanks dry. When = the engine quits from fuel starvation, you can not get a drop of fuel = out of the sumps. There are two of them on each wing and they are both = dry when the engine quits sitting on level ground. I think in flight would be a different matter tho'. I think there = should be some "unusable" in flight but I don't have any plans at = present to try and find out. When I get to =BC tank, I plan to "get er = down". =20 Assuming any kind of reserve, how much flying time did you feel you had = when you were down to 5 gal in each tank? Reading this last question, = it sounds like I am being critical but it couldn't be further from the = intent. :>) =20 If you had 5 gal in the tank, what angle of bank would it take to unport = the fuel on the ground? You could jack up one wing to try it. If it is = a low angle, very little turbulence would be required even if you were = coordinated. I think my dihedral is 3 degrees, so 4 degrees would run = everything to the outboard side. Hardly any movement of the plane and = you can hear fuel sloshing around in there. =20 Bill B =20 -------------------------------------------------------------------------= ------- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On = Behalf Of Mike Wills Sent: Saturday, March 13, 2010 11:29 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel supply problem? I'm pretty sure the turn was coordinated. Knowing that both tanks were = approaching (if not below) 5 gallons, it was the first thing I thought = of and I looked at the ball. It was centered. And I'm sure there is = going to turn out to be about 5 gallons left in the tank so its hard to = understand how this could have been an issue with the pickup uncovering. = I just don't have a better explanation. If the pump failed I would = expect it to stay failed, not work fine on the ground. =20 I didn't copy it, but my system I believe is the same that Ian Beadle = used. I have 1 pump for each tank. The outputs are T'eed together - = check valves built into the pumps prevents crossfeed. Both tanks have = return lines. The return line from the fuel rail goes through an = industrial grade electric valve. =20 I chose this design for a couple of reasons: 1) Operational simplicity. I reasoned that most fuel related problems in = flight are due to stupid pilot tricks so wanted a system that was as = simple to operate as possible. In its original configuration all that = was required to switch tanks was to flip a single toggle switch on the = panel which would energize the appropriate pump and configure the return = valve to return fuel to the tank it came from. This has since been = modified slightly to have individual switches for each pump so both can = be on at the same time if needed. 2) I had previous experience (bad) with EFI in some project cars before = I built the airplane. I had a couple of fuel pump failures and in = researching found strong recommendations against putting the fuel pump = too far from the fuel tank. These pumps are designed to push fuel, not = draw fuel. A design where both pumps have access to both tanks requires = the pumps to be downstream of the fuel selector with several feet of = fuel line ahead of the pump. I wanted to avoid this type of design = although it apparently is working fine for Ed. My pumps are just inboard = of the wing roots literally a couple of inches from the pickups in the = tanks. =20 Tracy's system is mechanically simple but has the potential for pilot = error resulting in pumping fuel overboard if the transfer pump is = forgotten and left on. Yes, I know there are ways to address that. And = clearly it works for him. =20 I think (thought?) I pretty well understand the pros and cons in my = setup. All things being equal I think before yesterday's incident I = would do it this way again. If it turns out that the issue was due to = uncovering the pickup (not real sure how to prove that) I'd consider = changing to include a header tank with a deep sump to prevent = re-occurance. But I don't think I'd rely on suction to fill the header, = think I'd use a low pressure pump like the typical Facet pump. =20 One thing is for certain. Unlike a carbureted engine which has a little = cushion due to fuel in a float bowl, the instant fuel pressure drops = this engine quits. It's an attention getter. Particularly when you are = at the opposite corner of your test box from your home base. I ended up = flying back about 70 miles hopscotching from field to field. =20 Mike=20 =20 From: Ed Anderson=20 Sent: Saturday, March 13, 2010 1:53 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: fuel supply problem? =20 There is certainly more than one way to design a reliable fuel system - = each with its pros and cons. I too did not want a six way value for = switching fuel between two tanks and the engine with the ugh return = line. Besides I had already constructed my fuel system pretty much = according to Van's instructions. So to preclude a return line I came up = with my "almost returnless" system. It uses a =BD pint capacity small = header tank to return the injector fuel - the fuel injected to the = engine comes from this header tank thereby creating a "vacuum" in the = tank which pulls fresh fuel from the wing tanks. It has worked fine for = over 10 years. =20 Both fuel pumps draw from this header tank and either tank can feed it = and I have no return lines going back to the tanks. =20 But, Tracy's approach has shown to work just fine - not knocking it by = any means. =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -------------------------------------------------------------------------= ------- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On = Behalf Of Bktrub@aol.com Sent: Friday, March 12, 2010 11:43 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel supply problem? =20 I just copied Tracy's setup- all fuel is pumped from the right tank, and = fuel is transferred from the left into the right by a Facet pump. I = didn't want to get into having a six port fuel valve in order to get the = fuel injection to return to the tank I was using at the time. =20 It's really simple, and hopefully that means reliable. We'll have to = see, as this plane is looking for it's airworthiness inspection in the = next few months.=20 =20 Brian Trubee __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ------=_NextPart_000_0054_01CAC2ED.1ABA38D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Bill,
 
My day got side tracked and I didn=92t get a = chance to=20 check it out today. My RV-4 holds 15.5 gallons per side (Vans says 32 = total).=20 The EFISM says there is 11 gallons left in the airplane and both the = quantity=20 gauges and my eyes say that the left tank (which was the problem tank) = now=20 actually has a little more fuel in it than the right tank which I flew = home and=20 landed on. The EFISM has proven to be pretty accurate so far. I havent = had it=20 all that long but it has never been off by more than a gallon. But the = real=20 answer wont be known until I fill the tanks, hopefully = tomorrow.
 
So in my RV, 5 gallons left in each tank = would=20 represent almost a third of the total fuel available. If I assume only = 21=20 gallons useable. That would be pretty unsatisfactory. And not at all = consistent=20 with my 150 hours of previous experience with my old RV-6A which has an = almost=20 identical fuel tank setup (total of 36 gallons vs 32).
 
Not sure what airplane you fly but the RVs = have=20 significant dihedral. No memorable turbulence at the time the problem = happened.=20 When I took off the EFISM said I had 27 gallons. The right tank was = completely=20 full, the left tank was down 4 gallons from full (if the EFISM can be = believed).=20 My first 50 minutes of flight were on the full right tank. I switched to = left=20 just before landing at Borrego to have something to drink. Then departed = on the=20 left tank. The problem happened at around 1.3 - 1.5 hours so maybe 30 = - 40=20 minutes of flight time plus one takeoff and climb on the left tank = when the=20 problem occurred.
 
Mike

Sent: Saturday, March 13, 2010 12:58 PM
Subject: [FlyRotary] Re: fuel supply = problem?

Hi Mike,

Have you removed and measured how much fuel = was actually=20 in the tanks?  What did your fuel gages say at the time?  What = is your=20 tank capacity?  Each wing on my plane holds 33 gal, so getting down = to 5=20 gal with very little dihedral in the wings, means I am pretty low on = fuel. =20 1/8 tank in fact.  The way I calibrated my gage was to drain the = tank dry,=20 add one gallon, calibrated this to be Zero, then added 4 gal and = calibrated this=20 to be 1/8, and then each 4 gal was another eighth, etc.  I think it = would=20 be very easy to unport my tanks with only 5 gal in them.  With the = plane=20 sitting level on the ground, it will drain the tanks dry.  When the = engine=20 quits from fuel starvation, you can not get a drop of fuel out of the=20 sumps.  There are two of them on each wing and they are both dry = when the=20 engine quits sitting on level ground.

I think in flight would be a different matter=20 tho=92.  I think there should be some =93unusable=94 in = flight but I don=92t=20 have any plans at present to try and find out.  When I get to =BC = tank, I=20 plan to =93get er down=94.

 

Assuming any kind of reserve, how much flying = time did=20 you feel you had when you were down to 5 gal in each tank?  Reading = this=20 last question, it sounds like I am being critical but it couldn=92t be = further=20 from the intent.  :>)

 

If you had 5 gal in the tank, what angle of = bank would=20 it take to unport the fuel on the ground?  You could jack up one = wing to=20 try it.  If it is a low angle, very little turbulence would be=20 required  even if you were coordinated.  I think my dihedral = is 3=20 degrees, so 4 degrees would run everything to the outboard side.  = Hardly=20 any movement of the plane and you can hear fuel sloshing around in=20 there.

 

Bill B

 

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Mike Wills
Sent: Saturday, March 13, 2010 = 11:29=20 AM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: fuel = supply=20 problem?

I'm pretty sure the turn = was=20 coordinated. Knowing that both tanks were approaching (if not = below) 5=20 gallons, it was the first thing I thought of and I looked at the ball. = It was=20 centered. And I'm sure there is going to turn out to be about 5 gallons = left in=20 the tank so its hard to understand how this could have been an issue = with the=20 pickup uncovering. I just don=92t have a better explanation. If the pump = failed I=20 would expect it to stay failed, not work fine on the=20 ground.

 

I didn=92t copy it, but = my system I=20 believe is the same that Ian Beadle used. I have 1 pump for each tank. = The=20 outputs are T'eed together - check valves built into the pumps prevents=20 crossfeed. Both tanks have return lines. The return line from the fuel = rail goes=20 through an industrial grade electric = valve.

 

I chose this design for = a couple=20 of reasons:

1) Operational = simplicity. I=20 reasoned that most fuel related problems in flight are due to stupid = pilot=20 tricks so wanted a system that was as simple to operate as possible. In = its=20 original configuration all that was required to switch tanks was to flip = a=20 single toggle switch on the panel which would energize the appropriate = pump and=20 configure the return valve to return fuel to the tank it came from. This = has=20 since been modified slightly to have individual switches for each pump = so both=20 can be on at the same time if needed.

2) I had previous = experience (bad)=20 with EFI in some project cars before I built the airplane. I had a = couple of=20 fuel pump failures and in researching found strong recommendations = against=20 putting the fuel pump too far from the fuel tank. These pumps are = designed to=20 push fuel, not draw fuel. A design where both pumps have access to both = tanks=20 requires the pumps to be downstream of the fuel selector with several = feet of=20 fuel line ahead of the pump. I wanted to avoid this type of design = although it=20 apparently is working fine for Ed. My pumps are just inboard of the wing = roots=20 literally a couple of inches from the pickups in the=20 tanks.

 

Tracy's system is = mechanically simple=20 but has the potential for pilot error resulting in pumping fuel = overboard if the=20 transfer pump is forgotten and left on. Yes, I know there are ways to = address=20 that. And clearly it works for him.

 

I think (thought?) I = pretty well=20 understand the pros and cons in my setup. All things being equal I = think=20 before yesterday's incident I would do it this way again. If it = turns out=20 that the issue was due to uncovering the pickup (not real sure how to = prove=20 that) I'd consider changing to include a header tank with a deep sump to = prevent=20 re-occurance. But I don=92t think I'd rely on suction to fill the = header, think=20 I'd use a low pressure pump like the typical Facet=20 pump.

 

One thing is for = certain. Unlike a=20 carbureted engine which has a little cushion due to fuel in a float = bowl, the=20 instant fuel pressure drops this engine quits. It's an attention getter. = Particularly when you are at the opposite corner of your test box from = your home=20 base. I ended up flying back about 70 miles hopscotching from field to=20 field.

 

Mike 

 

From: Ed=20 Anderson

Sent: Saturday,=20 March 13, 2010 1:53 AM

To: Rotary motors in = aircraft=20

Subject:=20 [FlyRotary] Re: fuel supply=20 problem?

 

There is = certainly more=20 than one way to design a reliable fuel system =96 each with its pros and = cons.  I too did not want a six way value for switching fuel = between two=20 tanks and the engine with the ugh return line.  Besides I had = already=20 constructed my fuel system pretty much according to Van=92s = instructions.  So=20 to preclude a return line I came up with my =93almost returnless=94 = system.  It=20 uses a =BD pint capacity small header tank to return the injector fuel = =96 the fuel=20 injected to the engine comes from this header tank thereby creating a = =93vacuum=94=20 in the tank which pulls fresh fuel from the wing tanks.  It has = worked fine=20 for over 10 years.

 

Both fuel = pumps draw=20 from this header tank and either tank can feed it and I have no return = lines=20 going back to the tanks.

 

But, = Tracy=92s = approach has shown=20 to work just fine =96 not knocking it by any = means.

 

Ed

 

Ed=20 Anderson

Rv-6A N494BW=20 Rotary Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Bktrub@aol.com
Sent: Friday, March 12, 2010 = 11:43=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: fuel = supply=20 problem?

 

I just = copied=20 Tracy's setup-=20 all fuel is pumped from the right tank, and fuel is transferred from the = left=20 into the right by a Facet pump. I didn't want to get into having a six = port fuel=20 valve in order to get the fuel injection to return to the tank I was = using at=20 the time.  

It's really = simple,=20 and hopefully that means reliable. We'll have to see, as this plane is = looking=20 for it's airworthiness inspection in the next few months.=20

 

Brian=20 Trubee



__________=20 Information from ESET NOD32 Antivirus, version of virus signature = database 3267=20 (20080714) __________

The message was checked by ESET NOD32=20 Antivirus.

http://www.eset.com

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