Today's Message Index:
----------------------
1. 05:45 AM - Re: Switch wiring conundrum (Roger)
2. 05:45 AM - Re: Switch wiring conundrum (Ken)
3. 06:13 AM - Re: self weighing our planes (glen matejcek)
4. 08:06 AM - Re: Re: self weighing our planes (Robert L. Nuckolls, III)
5. 08:54 AM - Re: Switch wiring conundrum (Mark R. Supinski)
6. 09:53 AM - Re: Re: self weighing our planes (Ernest Christley)
7. 10:34 AM - Re: Re: self weighing our planes (Richard E. Tasker)
8. 01:06 PM - Re: Switch wiring conundrum (Sam Hoskins)
9. 02:40 PM - DP3T switch? Switch wiring conundrum (Ed Anderson)
10. 03:27 PM - Re: Re: self weighing our planes (David M.)
11. 07:09 PM - Re: Switch wiring conundrum (Ken)
12. 08:45 PM - Re: Re: self weighing our planes (BobsV35B@aol.com)
13. 09:11 PM - Icom A-210 intercom (chris Sinfield)
14. 09:27 PM - Re: Switch wiring conundrum (Mark R. Supinski)
Message 1
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| Subject: | Re: Switch wiring conundrum |
Hello everyone-
I've been wracking my brain trying to figure out a way to control my
EFI injectors using a single 2-XX switch. I can't find a way to do what
I want to do (perhaps there is no way).
Here's what I'm trying to accomplish:
I have 2 banks of injectors. I need to be able to wire them such that
I have a single 3 position switch (Primary - Both - Secondary). That
part is easy enough using a 2-10. Here's the added trick: whenever
Both is not selected, I need to tie a certain line on the EFI to ground.
(This lets the EFI know one bank is offline & it automatically doubles
the fuel flow through the remaining bank.)
The suggested implementation from the EFI manufacturer is to wire each
bank to a 2-3. One side of 2-3 control whether the bank gets power, the
other side controls whether the EFI line ties to ground. When an
injector bank has failed, the pilot is "guessing" which bank to take
offline. If he guesses right, the engine smooths out & all is well for
a no-sweat landing. If he guesses wrong, the engine runs off & he must
quickly restore power to the bank he just turned off & remove power from
the "other" bank. Using two separate switches for this seems like a
recipe for frantically flipping switches to try to get the engine back
on if the pilot guesses wrong. My idea is that if it is a single
pri-both-sec switch, it is much easier to simply reverse the position of
the single switch you already have a hold of should the guess be wrong.
Hopefully someone is cleverer than I am and can figure out how to do
this without requiring 2 switches! Or, at least I can find out it is
impossible & I can resign myself to having two switches.
Thanks,
Mark
I think you are overlooking an important point. With one switch you
have a "single point of failure", which cauld kill both EFI's
simultaneously. My preference/recommendation is TWO switches.
Roger
Message 2
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| Subject: | Re: Switch wiring conundrum |
My first thought would be to use a transistor or NAND gate chip to
reverse the logic of the on signal.
Second thought is that you may not want to flick switches in a hurry. I
run independent systems and it does take a second to fill the second
fuel rail if I don't prime it first. By that I mean the second fuel rail
seems to get the fuel very slowly sucked out of it during cruise.
Third thought is that I would not use a single switch point of failure
for both injectors anyway. Note that it is no big deal if the engine
gets double the required fuel for a short period. It will still run and
make power during that time. Another option is to use a mechanical bar
arranged to mechanically operate two or more switches simultaneously.
Ken
Mark R. Supinski wrote:
> Hello everyone-
>
> I've been wracking my brain trying to figure out a way to control my EFI
> injectors using a single 2-XX switch. I can't find a way to do what I
> want to do (perhaps there is no way).
>
> Here's what I'm trying to accomplish:
>
> I have 2 banks of injectors. I need to be able to wire them such that I
> have a single 3 position switch (Primary - Both - Secondary). That part
> is easy enough using a 2-10. Here's the added trick: whenever Both is
> not selected, I need to tie a certain line on the EFI to ground. (This
> lets the EFI know one bank is offline & it automatically doubles the
> fuel flow through the remaining bank.)
>
> The suggested implementation from the EFI manufacturer is to wire each
> bank to a 2-3. One side of 2-3 control whether the bank gets power, the
> other side controls whether the EFI line ties to ground. When an
> injector bank has failed, the pilot is "guessing" which bank to take
> offline. If he guesses right, the engine smooths out & all is well for
> a no-sweat landing. If he guesses wrong, the engine runs off & he must
> quickly restore power to the bank he just turned off & remove power from
> the "other" bank. Using two separate switches for this seems like a
> recipe for frantically flipping switches to try to get the engine back
> on if the pilot guesses wrong. My idea is that if it is a single
> pri-both-sec switch, it is much easier to simply reverse the position of
> the single switch you already have a hold of should the guess be wrong.
>
> Hopefully someone is cleverer than I am and can figure out how to do
> this without requiring 2 switches! Or, at least I can find out it is
> impossible & I can resign myself to having two switches.
>
> Thanks,
>
> Mark
>
Message 3
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| Subject: | RE: self weighing our planes |
> Fascinating. Do the docs give any clue what the data source is for
>this calculation?
No, it's just a one-liner that says it happens. I was curious as to how
this is accomplished as well, but that detail doesn't seem to be in the
pilot docs. Or, at least my non-exhaustive search didn't turn it up.
glen matejcek
aerobubba@earthlink.ne
Message 4
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| Subject: | Re: RE: self weighing our planes |
At 08:24 PM 7/3/2009, you wrote:
>Good Evening Dennis,
>
>Most engine torque meters get their information from sensors mounted
>within the reduction gear housing on the engine. It measures the
>amount of pressure applied to the ring gear. Works quite well and
>is very reliable. First developed for large radials during
>WWII. Works good on turbo props as well.
>
>Happy Skies,
>
>Old Bob
>
>In a message dated 7/3/2009 7:54:38 P.M. Central Daylight Time,
>pinetownd@volcano.net writes:
>The C-130s I flew at the tail end of the Vietnam war all had fancy
>and expensive weight and balance computers. The system measured the
>weight on each wheel and displayed the airplane's gross weight and
>center of gravity.
>
>I don't know of any that worked, however. The common belief was
>that the computer went out of calibration after the first
>landing. All loadmasters I knew used a wooden slide rule specially
>designed for the C-130. So far as I know, the slide rule never went
>out of calibration.
>
>On the other hand, one of our primary engine gauges was the amount
>of torque the jet engine was applying to the propeller. I don't
>know, but it may have been based on strain gauges. The torque
>meters always seemed to be accurate and stable.
Yes, these are situations where the strain sensors are
housed within protected environments and VERY important,
spend a lot of time with zero stress on them. i.e. the
sensors are much less likely to creep (acquire offsets
to calibration), offsets are easily spotted if they
happen (gage doesn't read zero when then engine is
stopped). Most important, the elements in which strain
is measured can be tailored to the task. I.e. The
full scale capabilities of the strain gage can be
exploited.
I think the earliest torque measuring systems were
pure hydraulic. The reaction force in a gearbox was
impressed on a piston that compressed a fluid
where pressure gages at the other ends of plumbing
could be calibrated in values of torque. I think
they're still hydraulic but with a pressure transducer
mounted on the gear box as opposed to taking a tube
into the cockpit.
This is an example of an ideal application of
a strain gage where the force to be quantified is
unidirectional by design and relatively free of
noise.
The vast majority of pressure transducer designs
use some form of strain sensor on a diaphram.
http://www.aeroelectric.com/Reference_Docs/Patents/Silicon_Pressure_Gage_4287772.pdf
Since 1960 or so, a new silicon chip strain
sensor has been under development that has a much
higher output voltage. I suspect that very few
new transducer products use wire-wound or foil
strain gages any more.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 5
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| Subject: | Re: Switch wiring conundrum |
Well, that's certainly something to stew on.
I wish I had better information on what the failure modes for these
injectors really were. For instance -- do injectors fail open or fail
closed? Wiring in the switching is optional in the manual - implying I could
happily go flying with no ability to disable injector banks in flight. I
truly do not have room for two switches without making radical changes. I
think I have to go stare at the drawings and the physical panel some more &
either come to terms with no switches or two switches...
Thanks all-
Mark
On Sat, Jul 4, 2009 at 6:43 AM, Roger <mrspudandcompany@verizon.net> wrote:
>
>
> Hello everyone-
>
> I've been wracking my brain trying to figure out a way to control my EFI
> injectors using a single 2-XX switch. I can't find a way to do what I want
> to do (perhaps there is no way).
>
> Here's what I'm trying to accomplish:
>
> I have 2 banks of injectors. I need to be able to wire them such that I
> have a single 3 position switch (Primary - Both - Secondary). That part is
> easy enough using a 2-10. Here's the added trick: whenever Both is not
> selected, I need to tie a certain line on the EFI to ground. (This lets the
> EFI know one bank is offline & it automatically doubles the fuel flow
> through the remaining bank.)
>
> The suggested implementation from the EFI manufacturer is to wire each bank
> to a 2-3. One side of 2-3 control whether the bank gets power, the other
> side controls whether the EFI line ties to ground. When an injector bank
> has failed, the pilot is "guessing" which bank to take offline. If he
> guesses right, the engine smooths out & all is well for a no-sweat landing.
> If he guesses wrong, the engine runs off & he must quickly restore power to
> the bank he just turned off & remove power from the "other" bank. Using two
> separate switches for this seems like a recipe for frantically flipping
> switches to try to get the engine back on if the pilot guesses wrong. My
> idea is that if it is a single pri-both-sec switch, it is much easier to
> simply reverse the position of the single switch you already have a hold of
> should the guess be wrong.
>
> Hopefully someone is cleverer than I am and can figure out how to do this
> without requiring 2 switches! Or, at least I can find out it is impossible
> & I can resign myself to having two switches.
>
> Thanks,
>
> Mark
>
> I think you are overlooking an important point. With one switch you have
> a "single point of failure", which cauld kill both EFI's simultaneously. My
> preference/recommendation is TWO switches.
>
> Roger
>
> *
>
> *
>
>
Message 6
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| Subject: | Re: RE: self weighing our planes |
Robert L. Nuckolls, III wrote:
> I suspect that very few
> new transducer products use wire-wound or foil
> strain gages any more.
>
Most now use piezoelectric elements. Squeeze a piece of quartz crystal
and its resonant frequency changes in proportion to the pressure
applied. A relatively simple circuit measures the difference between
the strained piece of quartz and a reference piece.
--
http://www.ernest.isa-geek.org
Message 7
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| Subject: | Re: RE: self weighing our planes |
Only most of the high precision sensors use the quartz crystal sensing
technology. Very accurate and stable but expensive technology for
pressure sensing.
The vast majority of pressure sensors out there at moderate prices ($50
to $500) use some form of piezoresistive silicon strain gauges - either
mono-crystalline or poly-crystalline designs. And as Bob noted, sensors
based on silicon have significantly higher sensitivity. The typical
bonded strain gauge bridge has a full scale sensitivity of 3mV/V (mV of
output at full scale strain/pressure per volt of excitation) while the
typical mono-crystalline silicon strain gauge bridge has at least 10
mV/V and 20 mV/V is relatively easy. Bridges using poly-crystalline
silicon fall somewhere in the middle of the above two technologies.
The low end pressure sensors still use resistive elements - cheap
technology but not very accurate or linear.
Dick Tasker
Ernest Christley wrote:
> <echristley@nc.rr.com>
>
> Robert L. Nuckolls, III wrote:
>> I suspect that very few
>> new transducer products use wire-wound or foil
>> strain gages any more.
>>
>
> Most now use piezoelectric elements. Squeeze a piece of quartz
> crystal and its resonant frequency changes in proportion to the
> pressure applied. A relatively simple circuit measures the difference
> between the strained piece of quartz and a reference piece.
>
--
Please Note:
No trees were destroyed in the sending of this message. We do concede, however,
that a significant number of electrons may have been temporarily inconvenienced.
--
Message 8
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| Subject: | Re: Switch wiring conundrum |
Mark - FWIW, I went through this same conundrum earlier this year. I
finally grasped the fact that two switches would be the most reliable.
Sam
www.samhoskins.blogspot.com
On Sat, Jul 4, 2009 at 10:52 AM, Mark R. Supinski
<mark.supinski@gmail.com>wrote:
> Well, that's certainly something to stew on.
>
> I wish I had better information on what the failure modes for these
> injectors really were. For instance -- do injectors fail open or fail
> closed? Wiring in the switching is optional in the manual - implying I could
> happily go flying with no ability to disable injector banks in flight. I
> truly do not have room for two switches without making radical changes. I
> think I have to go stare at the drawings and the physical panel some more &
> either come to terms with no switches or two switches...
>
> Thanks all-
>
> Mark
>
> On Sat, Jul 4, 2009 at 6:43 AM, Roger <mrspudandcompany@verizon.net>wrote:
>
>>
>>
>>
>> Hello everyone-
>>
>> I've been wracking my brain trying to figure out a way to control my EFI
>> injectors using a single 2-XX switch. I can't find a way to do what I want
>> to do (perhaps there is no way).
>>
>> Here's what I'm trying to accomplish:
>>
>> I have 2 banks of injectors. I need to be able to wire them such that I
>> have a single 3 position switch (Primary - Both - Secondary). That part is
>> easy enough using a 2-10. Here's the added trick: whenever Both is not
>> selected, I need to tie a certain line on the EFI to ground. (This lets the
>> EFI know one bank is offline & it automatically doubles the fuel flow
>> through the remaining bank.)
>>
>> The suggested implementation from the EFI manufacturer is to wire each
>> bank to a 2-3. One side of 2-3 control whether the bank gets power, the
>> other side controls whether the EFI line ties to ground. When an injector
>> bank has failed, the pilot is "guessing" which bank to take offline. If he
>> guesses right, the engine smooths out & all is well for a no-sweat landing.
>> If he guesses wrong, the engine runs off & he must quickly restore power to
>> the bank he just turned off & remove power from the "other" bank. Using two
>> separate switches for this seems like a recipe for frantically flipping
>> switches to try to get the engine back on if the pilot guesses wrong. My
>> idea is that if it is a single pri-both-sec switch, it is much easier to
>> simply reverse the position of the single switch you already have a hold of
>> should the guess be wrong.
>>
>> Hopefully someone is cleverer than I am and can figure out how to do this
>> without requiring 2 switches! Or, at least I can find out it is impossible
>> & I can resign myself to having two switches.
>>
>> Thanks,
>>
>> Mark
>>
>> I think you are overlooking an important point. With one switch you
>> have a "single point of failure", which cauld kill both EFI's
>> simultaneously. My preference/recommendation is TWO switches.
>>
>> Roger
>>
>> *
>>
>> ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
>> tp://forums.matronics.com
>> _blank">http://www.matronics.com/contribution
>> *
>>
>>
> *
>
> *
>
>
Message 9
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| Subject: | Switch wiring conundrum |
Hi Mark,
>From one of your messages, I understand you stated you simply do not have
room for the two switch set up. While as indicated in the manual, you can
indeed go flying without a disable switch, I think you will find that the
benefits of the two switch system is worth additional effort. In event you
do have a problem with one bank of injectors or the other, you can disable
or turn them off and continue running more or less normally on the remaining
bank.
Here is what may not be apparent, the two switch system does more than just
turn on/off one of the other set of injectors (if that was all it did you
could accomplish the same thing by just having a power switch for each bank)
, it also grounds the EC's "Cold Start" function. When that is grounded it
automatically doubles the pulse duration to your injectors. True one bank
is now disabled, so it does not turn on, but the other bank has its flow
rated doubled.
So without it, if you turn off one set, then the same pulse duration is
now being sent to half as many injectors, therefore your fuel flow is cut
in half - meaning you are going to have to reach very quickly for that
mixture control and crank it up to full rich. I do not recall, but I think
the mixture control will only vary your flow by perhaps 25% (I could be
wrong about this), so you may have difficulty getting the initial fuel flow
back by mixture along - at the very least you are going to have to be
messing with your mixture control during a period when things might be a bit
stressful..
However, if you do have the two switch set up wired as recommended, the when
you switch off on bank of injectors, it will AUTOMATICALLY double the pulse
duration to the remaining bank of injectors thereby giving you close to
your original fuel flow (provided of course your single bank of injectors
are large enough to provide 75-100% of the total fuel flow you need). In
my rotary installation (which has four rather large injectors in two banks),
I have found the fuel flow easily provided more than adequate power on only
one bank.
Also, the disable feature can be great for trouble shooting injectors or
installation - not to mention that when you turn off /disable the injectors,
there is no fuel being pumped into the engine as it winds down.
If you truly can not find a way to place two DPDT switches - then a DP3T
switch might (I have not looked at it to see) provide a way to combine it
into one switch, but as several have mentioned, then that becomes a single
point of failure.
Decisions, decisions, decisions - not to mention compromises and
alternatives and redundancy all makes this a somewhat challenging endeavor.
Good luck.
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
<http://www.andersonee.com> http://www.andersonee.com
<http://www.dmack.net/mazda/index.html>
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
<http://members.cox.net/rogersda/rotary/configs.htm>
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
<http://www.dmack.net/mazda/index.html>
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Mark R.
Supinski
Sent: Friday, July 03, 2009 11:55 PM
Subject: AeroElectric-List: Switch wiring conundrum
Hello everyone-
I've been wracking my brain trying to figure out a way to control my EFI
injectors using a single 2-XX switch. I can't find a way to do what I want
to do (perhaps there is no way).
Here's what I'm trying to accomplish:
I have 2 banks of injectors. I need to be able to wire them such that I
have a single 3 position switch (Primary - Both - Secondary). That part is
easy enough using a 2-10. Here's the added trick: whenever Both is not
selected, I need to tie a certain line on the EFI to ground. (This lets the
EFI know one bank is offline & it automatically doubles the fuel flow
through the remaining bank.)
The suggested implementation from the EFI manufacturer is to wire each bank
to a 2-3. One side of 2-3 control whether the bank gets power, the other
side controls whether the EFI line ties to ground. When an injector bank
has failed, the pilot is "guessing" which bank to take offline. If he
guesses right, the engine smooths out & all is well for a no-sweat landing.
If he guesses wrong, the engine runs off & he must quickly restore power to
the bank he just turned off & remove power from the "other" bank. Using two
separate switches for this seems like a recipe for frantically flipping
switches to try to get the engine back on if the pilot guesses wrong. My
idea is that if it is a single pri-both-sec switch, it is much easier to
simply reverse the position of the single switch you already have a hold of
should the guess be wrong.
Hopefully someone is cleverer than I am and can figure out how to do this
without requiring 2 switches! Or, at least I can find out it is impossible
& I can resign myself to having two switches.
Thanks,
Mark
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3267 (20080714) __________
The message was checked by ESET NOD32 Antivirus.
Message 10
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| Subject: | Re: RE: self weighing our planes |
That is one reason I tried to come up with something. What if your
runway isn't long enough for you to hold that 9 degrees until liftoff?
I would like to know my weight per wheel (and can then easily calculate
CG) *before* I even start moving, in case I have to leave someone behind. :)
Or maybe dump a little fuel. Don't know how I'd to that on an OBAM but
I'd figure something out rather than take off way too heavy. If I'm
just going around the block that means I'll be landing way too heavy, too.
David
BobsV35B@aol.com wrote:
> Good Morning aerobubba,
>
> Any of us can do the same if we wish to go to the trouble of getting
> highly accurate calibration of all factors involved. For any specific
> weight and any specific angle of attack there will be just one speed
> at which the aircraft will leave the ground.
>
> If we note that speed and adjust for all the other pertinent factors
> we will have the weight.
>
> I have used that technique to some degree when flying the DC-8 in a
> charter operation. I found that if my weight really was what the
> paperwork said it was and I initiated rotation when the book said I
> should, the DC-8 would leave the surface at a nine degree nose up
> attitude. When I started to find airplanes in the charter operation
> that didn't do what I expected, I began to evaluate each takeoff very
> carefully.
>
> If I rotated to nine degrees and it did not fly, I held the nine
> degrees until it did lift off. I would then add two thousand pounds
> to whatever my weight manifest said for each knot above the normal
> lift off speed that I attained by holding the nine degrees. If I then
> added that extra weight to my performance calculations, all became
> normal.
>
> As an example, if the lift off speed was ten knots higher than had
> been calculated I would be twenty thousand pounds heavier than the
> paperwork showed. By using that new weight to establish climb and
> cruise numbers, the airplane would deliver the performance required.
> Hopefully, modern techniques for gathering the data for weight
> manifests have improved drastically in the thirty-five plus years
> since I flew those charters, but it worked well for me!
>
> Happy Skies,
>
> Old Bob
>
> Downers Grove, IL
> LL22
> Stearman N3977A
>
> <<<snip>>>
>
Message 11
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| Subject: | Re: Switch wiring conundrum |
FWIW here is my opinion on electronic injectors:
The most likely failure mode is low flow due clogging or zero flow due
to a wiring fault. Clogging/leaking risk is likely raised on some
aircraft due to using filters that are not as fine as in automobiles.
Coil failure resulting in no flow or continuous (stuck on) flow is rare
but both have been known to occur I'm told. I consider a stuck on
injector or a leaking injector to have no serious consequence for
aviation other than a rough idle after landing. And of coarse some fire
risk when on the ground or at idle.
ie. the major risk is a wiring problem or blown fuse/relay caused by a
wiring problem.
Ken
Mark R. Supinski wrote:
> Well, that's certainly something to stew on.
>
> I wish I had better information on what the failure modes for these
> injectors really were. For instance -- do injectors fail open or fail
> closed?
Message 12
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| Subject: | Re: RE: self weighing our planes |
Good Evening David,
Sorry if you got the impression that I was suggesting using my procedure as
a means of checking the weight of your aircraft prior to a takeoff!
My comment was in response to a note which said that the Airbus supplied a
weight figure following takeoff. The submitter seemed to wonder how that
could be done, I was just mentioning one way such a determination could be
made.
As to what to do if I found find nine degrees wasn't going to get me
airborne, that really depends on how much runway is left and how bad the crash
will be if I abort.
Fortunately for me, I was flying a four engine airplane and our performance
numbers were based on having three running and the most critical engine
failed at the most inopportune time. That meant that if all four were still
running, we had some wiggle room if the aircraft was over the weight shown
on the weight manifest.
It was my experience with some very poor data being provided on charter
trips that got me to develop my little checking procedure and, as I could
verify sloppy work by those who provided the data, I could take steps to get
the quality of the data improved.
I do not recommend ever operating intentionally at any loading not approved
for the airplane, but there are simple methods that we can use to help
keep everyone honest and on their toes.
Happy Skies,
Old Bob
In a message dated 7/4/2009 5:29:04 P.M. Central Daylight Time,
ainut@hiwaay.net writes:
That is one reason I tried to come up with something. What if your runway
isn't long enough for you to hold that 9 degrees until liftoff?
I would like to know my weight per wheel (and can then easily calculate
CG) *before* I even start moving, in case I have to leave someone behind. :)
Or maybe dump a little fuel. Don't know how I'd to that on an OBAM but
I'd figure something out rather than take off way too heavy. If I'm just
going around the block that means I'll be landing way too heavy, too.
David
_BobsV35B@aol.com_ (mailto:BobsV35B@aol.com) wrote:
Good Morning aerobubba,
Any of us can do the same if we wish to go to the trouble of getting
highly accurate calibration of all factors involved. For any specific weight and
any specific angle of attack there will be just one speed at which the
aircraft will leave the ground.
If we note that speed and adjust for all the other pertinent factors we
will have the weight.
I have used that technique to some degree when flying the DC-8 in a
charter operation. I found that if my weight really was what the paperwork said
it was and I initiated rotation when the book said I should, the DC-8 would
leave the surface at a nine degree nose up attitude. When I started to find
airplanes in the charter operation that didn't do what I expected, I began
to evaluate each takeoff very carefully.
If I rotated to nine degrees and it did not fly, I held the nine degrees
until it did lift off. I would then add two thousand pounds to whatever my
weight manifest said for each knot above the normal lift off speed that I
attained by holding the nine degrees. If I then added that extra weight to
my performance calculations, all became normal.
As an example, if the lift off speed was ten knots higher than had been
calculated I would be twenty thousand pounds heavier than the paperwork
showed. By using that new weight to establish climb and cruise numbers, the
airplane would deliver the performance required. Hopefully, modern techniques
for gathering the data for weight manifests have improved drastically in the
thirty-five plus years since I flew those charters, but it worked well for
me!
Happy Skies,
Old Bob
Downers Grove, IL
LL22
Stearman N3977A
<<<snip>>>
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| Subject: | Icom A-210 intercom |
Hi
speaking of intercoms, I just bought a new Icom 210 and want to put it into my
2 seater. Does the 2 place VOX system work OK should I have a seperate 2 place
intercom.
I just want to be able to talk to my pax, TX from either position and have an MP3
input. to both..
Chris.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=251546#251546
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| Subject: | Re: Switch wiring conundrum |
Thanks to everyone for their thoughts.
I "bit the bullet" and celebrated the 4th of July by spending a delightful 5
hours under my instrument panel moving components / rewiring / etc to
shoe-horn in room for another switch -- which got in there with 0.05" to
spare. God then smiled on me & miraculously there were even two new 2-3
switches squirreled away in the back of the tool chest to allow me to
directly replace the old 2-10.
Mark
On Sat, Jul 4, 2009 at 8:05 PM, Ken <klehman@albedo.net> wrote:
>
> FWIW here is my opinion on electronic injectors:
>
> The most likely failure mode is low flow due clogging or zero flow due to a
> wiring fault. Clogging/leaking risk is likely raised on some aircraft due to
> using filters that are not as fine as in automobiles.
>
> Coil failure resulting in no flow or continuous (stuck on) flow is rare but
> both have been known to occur I'm told. I consider a stuck on injector or a
> leaking injector to have no serious consequence for aviation other than a
> rough idle after landing. And of coarse some fire risk when on the ground or
> at idle.
>
> ie. the major risk is a wiring problem or blown fuse/relay caused by a
> wiring problem.
>
> Ken
>
> Mark R. Supinski wrote:
>
>> Well, that's certainly something to stew on.
>> I wish I had better information on what the failure modes for these
>> injectors really were. For instance -- do injectors fail open or fail
>> closed?
>>
>
>
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