Today's Message Index:
----------------------
1. 12:02 AM - Official Usage Guideline [Please Read] [Monthly Posting] (Matt Dralle)
2. 01:07 AM - Re: purpose of fire sleeve (Jim Jewell)
3. 06:43 PM - Hey, Where's My List Mail Today...? (Matt Dralle)
4. 07:26 PM - Re: [Bulk] Rv-List Power Required (Ed Holyoke)
5. 07:26 PM - Re: [Bulk] Rv-List Power Required (Ed Holyoke)
6. 10:28 PM - Re: [Bulk] Rv-List Power Required (Jim Oke)
Message 1
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| Subject: | Official Usage Guideline [Please Read] [Monthly Posting] |
DNA: do not archive
--> RV-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Lister,
Please read over the RV-List Usage Guidelines below. The complete
RV-List FAQ including these Usage Guidelines can be found at the
following URL:
http://www.matronics.com/FAQs/RV-List.FAQ.html
Thank you,
Matt Dralle
Matronics Email List Administrator
******************************************************************************
RVSouthEast-List Usage Guidelines
******************************************************************************
The following details the official Usage Guidelines for the RVSouthEast-List.
You are encouraged to read it carefully, and to abide by the rules therein.
Failure to use the RVSouthEast-List in the manner described below may result
in the removal of the subscribers from the List.
RVSouthEast-List Policy Statement
The purpose of the RVSouthEast-List is to provide a forum of discussion for
things related to this particular discussion group. The List's goals
are to serve as an information resource to its members; to deliver
high-quality content; to provide moral support; to foster camaraderie
among its members; and to support safe operation. Reaching these goals
requires the participation and cooperation of each and every member of
the List. To this end, the following guidelines have been established:
- Please keep all posts related to the List at some level. Do not submit
posts concerning computer viruses, urban legends, random humor, long
lost buddies' phone numbers, etc. etc.
- THINK carefully before you write. Ask yourself if your post will be
relevant to everyone. If you have to wonder about that, DON'T send it.
- Remember that your post will be included for posterity in an archive
that is growing in size at an extraordinary rate. Try to be concise and
terse in your posts. Avoid overly wordy and lengthy posts and
responses.
- Keep your signature brief. Please include your name, email address,
aircraft type/tail number, and geographic location. A short line
about where you are in the building process is also nice. Avoid
bulky signatures with character graphics; they consume unnecessary
space in the archive.
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easily obtainable from other widely available sources. Consult the
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can not be overstated!
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- DO NOT use the List to respond to a post unless you have something
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agree", and "Congratulations" are all responses that are better sent
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- When responding to others' posts, avoid the feeling that you need to
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- Feel free to disagree with other viewpoints, BUT keep your tone
polite and respectful. Don't make snide comments, personally attack
other listers, or take the moral high ground on an obviously
controversial issue. This will only cause a pointless debate that
will hurt feelings, waste bandwidth and resolve nothing.
-------
[This is an automated posting.]
Message 2
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| Subject: | Re: purpose of fire sleeve |
--> RV-List message posted by: "Jim Jewell" <jjewell@telus.net>
Hi Tom,
This topic tends to need some fire sleeve. ;-)
Fire sleeve is firstly intended to delay the negative effects of heat and
open flames on hoses, wires, etc.
Fuel hoses being a potential and volatile source for feeding a fire require
fire sleeve. (Mandatory on aircraft I.think)
Oil hoses being quite able to feed a fire are a close second.. Not mandatory
(Also good idea I think)
The fire sleeve will insulate the oil lines but oil lines are not generally
intended to be heat radiators unless deliberately designed that way
If the choice is to install fire sleeve there are some considerations:
If installing over rubber hoses be aware that the ends of the fire sleeve
need to be sealed and clamped tight to stop the invasion of condensation and
other environmental contaminants that will tend to reduce the expected life
cycle of the hoses being protected. There is a special product for this but
RTV can be utilized. (generally a very messy job)
Because the cut ends of fire sleeve are fuzzy and tend to release fibbers it
is advisable to use the sealant of choice on all installations. (it Does
look nicer)
With the stainless braided neoprene etc, hoses deterioration and rotting is
less of a consideration.
Does installing fire sleeve on fuel lines have a positive effect on in line
fuel vaporization?
Yes; it initially delays the invasion of heat into the fuel line during warm
up. (no biggy)
During flight the cooling effect of the fresh fuel flow will be more
effective because the fire sleeve will insulate the line thereby keeping the
coolness in the line as well as tending to keep the ambient heat out.
During an after shut down hot soak (no fuel flow) it will then first delay
the fairly short duration but noticeable heat increase.
Then it will tend to hold onto any heat gained, delaying the cooling off
period or until fuel movement begins again. This could be a negative effect
on starting during short duration shut offs.
Jim in Kelowna
----- Original Message -----
From: "thomas a. sargent" <sarg314@comcast.net>
Subject: RV-List: purpose of fire sleeve
> --> RV-List message posted by: "thomas a. sargent" <sarg314@comcast.net>
>
> I was advised today by one of the guys at Van's to not bother putting
> fire sleeve on oil lines. Just use it on the fuel lines.
>
> Is the purpose of fire sleeve just to insulate the fuel lines from heat
> of the engine, or is it to retard the progress of an engine fire, by
> protecting the combustible oil and fuel from flames? If it's just to
> keep the gas cool, then I guess he's right. If it's supposed to retard a
> fire, then I think oil lines should be firesleeved too, yes?
> --
> Tom Sargent
> RV-6A
>
>
>
Message 3
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| Subject: | Hey, Where's My List Mail Today...? |
--> RV-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Listers,
My sincere apologies today! This morning (Thursday) at about 3am the
Matronics Firewall broke. About 9am I was able to bring up an older
firewall and got everything back on line, or so I thought... While the web
pages were working, I had neglected to add a policy that allowed incoming
email to get to the email server (actually the SPAM filtering
appliance). I just checked my email for the first time today and noticed
that I hadn't gotten any List mail today. Hum, I thought, this can't be good!!
Anyway, I'm going to enable incoming email now on the firewall and things
should be back to normal. I'm sure sorry for the oversight. Hopefully
nobody had any withdrawals from lack of List banter today!! :-)
Best regards,
Matt Dralle
Email List Administrator
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
do not archive
Message 4
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| Subject: | Rv-List Power Required |
--> RV-List message posted by: "Ed Holyoke" <bicyclop@pacbell.net>
> I always thought that was the reason people turbocharge piston
airplanes
> and fly at high altitudes. It can't be for lessened fuel burn since
you
> gotta keep the mixture pretty rich in a turbocharged airplane to keep
> the cht's and tit's down, don't you?
when I first bought our Cessna TurboCenturion and took it up high, (
well,
FL220 seemed high, although it's ceiling was FL310, IIRC)I was surprized
that the same power setting yielded the same fuel flow and the exact
same
IAS.
I shouldn't have been surprized, just never thought about it, having
only
flown normally-aspirated engines up until that time.
The only thing that kept increasing with altitude was the TAS, I don't
think
the CHT and TIT changed noticeably.
Scott in VAncouver
Scott,
That's just what I expected. I thought, that with the same available
power (which you can maintain to higher altitude with a turbocharger),
you'd see higher true airspeed at higher altitude. But it seems that
Kevin predicts a lower tas with the same power. That's what I'm trying
to figure out.
I bet if you had leaned it out, both temperatures would've gone into the
red at least until you got high enough to where the engine couldn't
maintain anything like sea level power. ;-)
Ed Holyoke
Message 5
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| Subject: | Rv-List Power Required |
--> RV-List message posted by: "Ed Holyoke" <bicyclop@pacbell.net>
Hi Larry,
I read it again (and again and again), and I think that what Kevin said
was that 157 kts cas (calibrated airspeed which is indicated airspeed
corrected for installation errors, if I've got it right) is equal to 220
kts tas (true airspeed) at 22k ft. At sea level cas and tas are equal
(given standard temperature), right? He said that drag is roughly the
same for cas at differing altitudes and that power required is
proportional to drag times tas. I believe I understand what he said and
I can't fault his math, but I don't understand why it would be so.
Lift has to overcome gravity and thrust has to overcome drag at any
altitude. An engine has less ability to produce power at higher
altitude, but why should more power, assuming the engine could be
convinced to make it, be required to overcome, what I expect (perhaps
unrealistically), to be lower drag in the thinner air at higher
altitude? To me it's counterintuitive that drag would increase with
altitude. That's the part that I don't get.
I don't have any math to back it up, but shouldn't parasitic drag
decrease in thinner air? I've heard it said that induced drag is the
smaller part of total drag. Does the induced drag increase a lot (40
percent or more) as the wing struggles to make up the lift that is lost
through lower air density? Would this be because of the necessity of a
higher angle of attack to produce the same amount of lift?
Could it be not entirely an increase in drag but, in part, a decrease in
prop efficiency that is causing this effect? A prop is less efficient at
higher altitude, sure, but is it 40 percent less efficient?
When I said that Kevin knows more about this than I do, I wasn't being
facetious. I genuinely want to understand the principles involved.
Seeking knowledge,
Ed Holyoke
-----Original Message-----
From: owner-rv-list-server@matronics.com
[mailto:owner-rv-list-server@matronics.com] On Behalf Of Larry Pardue
Subject: Re: [Bulk] RV-List: Rv-List Power Required
--> RV-List message posted by: "Larry Pardue" <n5lp@warpdriveonline.com>
----- Original Message -----
From: "Ed Holyoke" <bicyclop@pacbell.net>
Subject: RE: [Bulk] RV-List: Rv-List Power Required
> --> RV-List message posted by: "Ed Holyoke" <bicyclop@pacbell.net>
>
> Kevin,
>
> I expect that you know a lot more about it than I do, but I just don't
> understand. Can you explain for a dunce why it takes more power to go
> the same speed at higher altitude?
>
Read it again. Kevin was comparing to a lower speed because that is
what he
had data on.
Larry Pardue
Carlsbad, NM
RV-6 N441LP Flying
http://n5lp.net
Message 6
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| Subject: | Re: Rv-List Power Required |
--> RV-List message posted by: Jim Oke <wjoke@shaw.ca>
Here is perhaps another way to think of things.
1. The airplane weighs the same at all usable altitudes.*
2. Thus the wing has produce the same amount of lift effect.
3. Since the air is less dense at altitude, you have to move the wing faster
through the air to get the same amount of lift.
4. Because you are going faster, the amount of drag increases too, even
though the air is less dense.
5. The two effects are exactly matched with the airspeed indicator, so that
the airplane, if operated at the same CAS, will have the same amount of lift
and drag. **
6. Power is a measure of the amount of work (which is the same as moving a
force through a distance) performed during a given period of time.
7. Let's say the airplane has a drag of say 200 lbs at 157 kts CAS.
8. At sea level, the airplane moves 157 nm in one hour, while at altitude
the airplane moves 220 nm in the same one hour of time, in each case working
against the same 200 lb drag force. .
9. So the airplane flying at altitude has moved the same force a greater
distance in the same time and so must have used more power to do so (as it
did more work in the same amount of time).
10. There being no free lunch in this line of business, you either need a
bigger engine or run more fuel through the same engine.
Jim Oke
Wpg., MB
RV-3, RV-6A
* Purists will note that gravitational force deceases as you go higher so
the airplane will actually "weigh" a bit less, the change is tiny until you
get many miles up.
** Assuming the various mach and Reynolds number effects can be disregarded.
----- Original Message -----
From: "Ed Holyoke" <bicyclop@pacbell.net>
Subject: RE: [Bulk] RV-List: Rv-List Power Required
> --> RV-List message posted by: "Ed Holyoke" <bicyclop@pacbell.net>
>
> Hi Larry,
>
> I read it again (and again and again), and I think that what Kevin said
> was that 157 kts cas (calibrated airspeed which is indicated airspeed
> corrected for installation errors, if I've got it right) is equal to 220
> kts tas (true airspeed) at 22k ft. At sea level cas and tas are equal
> (given standard temperature), right? He said that drag is roughly the
> same for cas at differing altitudes and that power required is
> proportional to drag times tas. I believe I understand what he said and
> I can't fault his math, but I don't understand why it would be so.
>
> Lift has to overcome gravity and thrust has to overcome drag at any
> altitude. An engine has less ability to produce power at higher
> altitude, but why should more power, assuming the engine could be
> convinced to make it, be required to overcome, what I expect (perhaps
> unrealistically), to be lower drag in the thinner air at higher
> altitude? To me it's counterintuitive that drag would increase with
> altitude. That's the part that I don't get.
>
> I don't have any math to back it up, but shouldn't parasitic drag
> decrease in thinner air? I've heard it said that induced drag is the
> smaller part of total drag. Does the induced drag increase a lot (40
> percent or more) as the wing struggles to make up the lift that is lost
> through lower air density? Would this be because of the necessity of a
> higher angle of attack to produce the same amount of lift?
>
> Could it be not entirely an increase in drag but, in part, a decrease in
> prop efficiency that is causing this effect? A prop is less efficient at
> higher altitude, sure, but is it 40 percent less efficient?
>
> When I said that Kevin knows more about this than I do, I wasn't being
> facetious. I genuinely want to understand the principles involved.
>
> Seeking knowledge,
>
> Ed Holyoke
>
>
> -----Original Message-----
> From: owner-rv-list-server@matronics.com
> [mailto:owner-rv-list-server@matronics.com] On Behalf Of Larry Pardue
> To: rv-list@matronics.com
> Subject: Re: [Bulk] RV-List: Rv-List Power Required
>
> --> RV-List message posted by: "Larry Pardue" <n5lp@warpdriveonline.com>
>
>
> ----- Original Message -----
> From: "Ed Holyoke" <bicyclop@pacbell.net>
> To: <rv-list@matronics.com>
> Subject: RE: [Bulk] RV-List: Rv-List Power Required
>
>
>> --> RV-List message posted by: "Ed Holyoke" <bicyclop@pacbell.net>
>>
>> Kevin,
>>
>> I expect that you know a lot more about it than I do, but I just don't
>> understand. Can you explain for a dunce why it takes more power to go
>> the same speed at higher altitude?
>>
>
> Read it again. Kevin was comparing to a lower speed because that is
> what he
> had data on.
>
> Larry Pardue
> Carlsbad, NM
>
> RV-6 N441LP Flying
> http://n5lp.net
>
>
>
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