Today's Message Index:
----------------------
1. 02:35 PM - Re: Stratus EA-81 Cooling (Andrew SanClemente)
2. 02:59 PM - Re: Stratus EA-81 Cooling (Hinde, Frank George (Corvallis))
Message 1
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| Subject: | Stratus EA-81 Cooling |
--> Stratus-List message posted by: Andrew SanClemente <ansancle@townisp.com>
Frank,
no embarrassment, I did plumb as you described - but that was also
how the factory told me to do it.
The first question I asked them when they described how to put the
pumps was "won't that pump sucking the fuel cause vapour-lock if the
wing pump fails?". They said it wouldn't and if I remember correctly
he said they had theirs plumbed that way at the time.
This didn't necessarily convince me but with the wing tank pump
pushing I didn't worry too much.
For me to have fuel starvation the following needs to happen :
1. One wing tank pump fails
=09- switch tanks and pumps
2. Other wing tank pump fails
- allow firewall pump to continue pumping
3. Firewall pump either fails or vapour-locks within minutes of 2
since flight will be terminated after 1 or 2.
4. I allow the flight to continue long enough for this to all
transpire.
I tend to doubt that a two pumps will fail within a few minutes and
the third will immediately cause vapour-lock before I could get down.
If I am being naive feel free to say so, rather have my feelings hurt
than kill myself.Feel free to let me know your thoughts and
recommendations, again, free exchange of ideas and knowledge is a
good thing and I won't be upset if you say I'm being a moron - just
do it nicely ;)
Thanks!
Andy
On Mon, 4 Oct 2004 11:43:24 -0700, Hinde, Frank George (Corvallis)
wrote:
>--> Stratus-List message posted by: "Hinde, Frank George
>(Corvallis)" <frank.hinde@hp.com>
>
>Andy,
>
>If you have don what I think you have, then I do not like your fuel
>system design.
>
>This is what I THINK you did...
>
>You put a single pump that draws from both tanks using a selector
>valve
>perhaps? You have a second pump on the firewall that is plumbed in
>series with the wing tanks.
>
>I say I think you did this because series plumbing of two pumps is
>the
>only way your pressure will double like that.
>
>Is this the case?...If so I think you should replumb your system as
>you
>are asking for vapour lock....with deadly consequences...Admittedly
>the
>the wing tank pump will have to fail for this to happen but its not
>ideal by any stretch.
>
>Let me know what you did and we can talk some more.
>
>I will post this to the group, not to embarrass you, just simply to
>get
>the word out.
>
>Frank
>
>
Frank,
no embarrassment, I did plumb as you described - but that was also how the factory
told me to do it.
The first question I asked them when they described how to put the pumps was won't
that pump sucking the fuel cause vapour-lock if the wing pump fails?. They
said it wouldn't and if I remember correctly he said they had theirs plumbed
that way at the time.
This didn't necessarily convince me but with the wing tank pump pushing I didn't
worry too much.
For me to have fuel starvation the following needs to happen :
1. One wing tank pump fails
- switch tanks and pumps
2. Other wing tank pump fails
- allow firewall pump to continue pumping
3. Firewall pump either fails or vapour-locks within minutes of 2 since flight
will be terminated after 1 or 2.
4. I allow the flight to continue long enough for this to all transpire.
I tend to doubt that a two pumps will fail within a few minutes and the third
will immediately cause vapour-lock before I could get down.
If I am being naive feel free to say so, rather have my feelings hurt than kill
myself.Feel free to let me know your thoughts and recommendations, again, free
exchange of ideas and knowledge is a good thing and I won't be upset if you
say I'm being a moron - just do it nicely ;)
Thanks!
Andy
On Mon, 4 Oct 2004 11:43:24 -0700, Hinde, Frank George (Corvallis) wrote:
--=A0Stratus-List message posted by: Hinde, Frank George
(Corvallis) frank.hinde@hp.com
Andy,
If you have don what I think you have, then I do not like your fuel
system design.
This is what I THINK you did...
You put a single pump that draws from both tanks using a selector
valve
perhaps? You have a second pump on the firewall that is plumbed in
series with the wing tanks.
I say I think you did this because series plumbing of two pumps is
the
only way your pressure will double like that.
Is this the case?...If so I think you should replumb your system as
you
are asking for vapour lock....with deadly consequences...Admittedly
the
the wing tank pump will have to fail for this to happen but its not
ideal by any stretch.
Let me know what you did and we can talk some more.
I will post this to the group, not to embarrass you, just simply to
get
the word out.
Frank
Message 2
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| Subject: | Stratus EA-81 Cooling |
--> Stratus-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Actually for some reason I thought you only had wing tanks...probably
been so long since I been flying with wing tanks only that I complety
forgot about the header tank.
Secondly I had assumed from your description that you only had two
pumps...One on the firewall and one for both wing tanks.
If you have a header the problem goes away because there is always
positive head over the firewall pump.
If you have THREE pumps (one at the outlet of each tank and one on the
firewall) and no header tank the problem also goes away...Except that
the firewall pump is a third level of protection (and designing to this
level is overkill) and the fuel pressure will go too high when two or
three pumps are run.
Personally I would remove the firewall pump if you don't have the
header.
The important thing here is to NOT suck on the fuel and have a redundant
pump that will also not suck on the fuel.....One pump at the outlet of
each tank is fine.
Also make sure each pump is fed from a separate electrical source (I
have two electrically isolated batteries, one ignition and one pump fed
from each battery)
Hope that helps
Frank
-----Original Message-----
From: owner-stratus-list-server@matronics.com
[mailto:owner-stratus-list-server@matronics.com] On Behalf Of Andrew
SanClemente
Subject: RE: Stratus-List: Stratus EA-81 Cooling
--> Stratus-List message posted by: Andrew SanClemente
--> <ansancle@townisp.com>
Frank,
no embarrassment, I did plumb as you described - but that was also
how the factory told me to do it.
The first question I asked them when they described how to put the
pumps was "won't that pump sucking the fuel cause vapour-lock if the
wing pump fails?". They said it wouldn't and if I remember correctly
he said they had theirs plumbed that way at the time.
This didn't necessarily convince me but with the wing tank pump
pushing I didn't worry too much.
For me to have fuel starvation the following needs to happen : 1. One
wing tank pump fails
=09- switch tanks and pumps
2. Other wing tank pump fails
- allow firewall pump to continue pumping
3. Firewall pump either fails or vapour-locks within minutes of 2
since flight will be terminated after 1 or 2.
4. I allow the flight to continue long enough for this to all
transpire.
I tend to doubt that a two pumps will fail within a few minutes and
the third will immediately cause vapour-lock before I could get down. If
I am being naive feel free to say so, rather have my feelings hurt
than kill myself.Feel free to let me know your thoughts and
recommendations, again, free exchange of ideas and knowledge is a
good thing and I won't be upset if you say I'm being a moron - just
do it nicely ;)
Thanks!
Andy
On Mon, 4 Oct 2004 11:43:24 -0700, Hinde, Frank George (Corvallis)
wrote:
>--> Stratus-List message posted by: "Hinde, Frank George
>(Corvallis)" <frank.hinde@hp.com>
>
>Andy,
>
>If you have don what I think you have, then I do not like your fuel
>system design.
>
>This is what I THINK you did...
>
>You put a single pump that draws from both tanks using a selector valve
>perhaps? You have a second pump on the firewall that is plumbed in
>series with the wing tanks.
>
>I say I think you did this because series plumbing of two pumps is the
>only way your pressure will double like that.
>
>Is this the case?...If so I think you should replumb your system as you
>are asking for vapour lock....with deadly consequences...Admittedly
>the
>the wing tank pump will have to fail for this to happen but its not
>ideal by any stretch.
>
>Let me know what you did and we can talk some more.
>
>I will post this to the group, not to embarrass you, just simply to get
>the word out.
>
>Frank
>
>
Frank,
no embarrassment, I did plumb as you described - but that was also
how the factory told me to do it.
The first question I asked them when they described how to put the
pumps was won't that pump sucking the fuel cause vapour-lock if the wing
pump fails?. They said it wouldn't and if I remember correctly he said
they had theirs plumbed that way at the time.
This didn't necessarily convince me but with the wing tank pump pushing
I didn't worry too much.
For me to have fuel starvation the following needs to happen : 1. One
wing tank pump fails
- switch tanks and pumps
2. Other wing tank pump fails
- allow firewall pump to continue pumping
3. Firewall pump either fails or vapour-locks within minutes of 2 since
flight will be terminated after 1 or 2. 4. I allow the flight to
continue long enough for this to all transpire. I tend to doubt that a
two pumps will fail within a few minutes and the third will immediately
cause vapour-lock before I could get down. If I am being naive feel
free to say so, rather have my feelings hurt than kill myself.Feel free
to let me know your thoughts and recommendations, again, free exchange
of ideas and knowledge is a good thing and I won't be upset if you say
I'm being a moron - just do it nicely ;)
Thanks!
Andy
On Mon, 4 Oct 2004 11:43:24 -0700, Hinde, Frank George (Corvallis)
wrote: --=A0Stratus-List message posted by: Hinde, Frank George
(Corvallis) frank.hinde@hp.com
Andy,
If you have don what I think you have, then I do not like your fuel
system design.
This is what I THINK you did...
You put a single pump that draws from both tanks using a selector
valve perhaps? You have a second pump on the firewall that is plumbed
in series with the wing tanks.
I say I think you did this because series plumbing of two pumps is the
only way your pressure will double like that.
Is this the case?...If so I think you should replumb your system as
you are asking for vapour lock....with deadly consequences...Admittedly
the the wing tank pump will have to fail for this to happen but its not
ideal by any stretch.
Let me know what you did and we can talk some more.
I will post this to the group, not to embarrass you, just simply to
get the word out.
Frank
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