Today's Message Index:
----------------------
1. 04:49 AM - Re: Ground Power - Z31A (Robert L. Nuckolls, III)
2. 04:56 AM - Re: Re: Rear Mounted Batteries - more questions (Robert L. Nuckolls, III)
3. 05:49 AM - "Chubby" wires and fuseblocks (Robert L. Nuckolls, III)
4. 06:13 AM - Switch ratings (Robert L. Nuckolls, III)
5. 06:17 AM - Re: Grommets (Jeff Page)
6. 07:06 AM - Re: Grommets (Bubblehead)
7. 07:35 AM - Re: Re: Grommets ()
8. 07:56 AM - Re: Re: Grommets (Bob White)
9. 07:57 AM - Re: Grommets (RALPH HOOVER)
10. 01:39 PM - Re: Re: Grommets (Rob Housman)
11. 02:00 PM - Re: Re: Grommets (Bryan)
12. 02:14 PM - Thermal expansion (was Grommets) (raymondj)
13. 03:12 PM - Re: Rear Mounted Batteries - more questions (n277dl)
14. 05:44 PM - A Bit of Help, Please (Speedy11@aol.com)
15. 06:44 PM - Re: A Bit of Help, Please (Joemotis@aol.com)
16. 06:55 PM - Questions on avionics ()
17. 07:13 PM - pinout for Softcom ATC-P intercom?? (Charlie England)
18. 07:22 PM - Re: A Bit of Help, Please (Robert L. Nuckolls, III)
19. 07:42 PM - Re: Re: Transponder for sale (mode S) (Charlie England)
20. 07:48 PM - Re: Questions on avionics (Ernest Christley)
21. 08:28 PM - Re: Questions on avionics (Mike)
22. 08:34 PM - Re: Questions on avionics (Mike)
Message 1
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| Subject: | Re: Ground Power - Z31A |
At 11:38 PM 4/16/2008 +0200, you wrote:
>
>Bob
>
>Please can you confirm the correct procedure for using the ground power on
>Z31a architecture.
>
>Is it imperative to first switch on the "ground power" switch, before
>switching on the master switch?
No. The ground power may be turned on at any time in the
starting sequence without regard to damage to the system.
The ground power circuits as depicted are reverse polarity
and ov protected . . .
>Would I just switch ground power off, once the aircraft has started?
Yes.
>What would happen if ground power switch was inadvertantly left on for an
>indefinite period, or turned on whilst the aircraft engine was running?
No big deal. IF the ground power source voltage was set
higher than your ship's regulator, your alternator
would not come on line and pick up system loads as long
as the ground power was connected. If you're getting a
start from a battery cart - as ship's systems came
alive, your ship's alternator would begin to charge/
re-charge ALL batteries in the system . . . including those
in a still connected ground power cart.
If you're using external power from an engine driven or
AC mains powered cart, then would would expect the external
voltage source to be set at "battery charging" voltage
levels (14.2 or 28.5). In this case, you could turn on
ground power long before closing the master switch and
let ground power replenish you ship's battery. After
15 minutes or so, your ship's battery may well contain
sufficient snort to start your engine and ground power
could be disconnected for the start an subsequent
pre-flight. If the ground power is a battery cart,
then no charging of the ship's battery can take place
and you're obligated to use ground power to get the
engine started. After starting, you'd want to turn
ground power off so that ALL of your ship's alternator
output was being used to replenish stored energy in
the ship's battery.
In cold weather, you may wish to use ground power
as a routine assist for getting the engine
started even if your battery is in good shape.
Aside from the possibility of too much ground power
voltage and/or reversed polarity, there are no risks to
your airplane's systems that warrant concern. Making
ground power managed from the pilot's seat
puts you in control of this resource for the purpose
of addressing the task at hand.
It's an energy management problem with solutions
determined by equipment available, condition of
your battery and immediate goals. I recall reading
a story many moons ago where a pilot used his ground
power jumper cables to get his car started using
his airplane's battery after returning from a trip
and finding the car battery was not up to the task.
>Your assistance as always is appreciated.
Pleased to be of service sir!
Bob . . .
Message 2
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| Subject: | Re: Rear Mounted Batteries - more questions |
At 02:54 PM 4/16/2008 -0700, you wrote:
>
>Bob and list,
> Using the previously attached document as reference...
>
>Assumptions... rear mounted batteries. Main Bat Cntctr, Aux Bat cntctr
>and Xfeed Cntctr all mounted in rear beside the batteries.
Hmmmm . . . normally we'd like to see the cross-feed contactor
mounted on the firewall. This provides nice fat-wire terminals
from both batteries to serve as distribution points for the
two batteries in addressing their respective tasks.
> 2awg ground wire to fwd central gnd bus attached to the engine via stud
> through firewall. XFEED cnctr closed for starting. 2AWG wire from the
> same side of XFEED cntctr that the main bat cntctr is connected to
> starter cntctr.
Okay . . .
>Questions.... Can I then run appropriate sized wire (tbd) from the same
>side of the starter cntctr as the 2awg wire is attached to the main pwr bus?
Yes. If your cross-feed contactor were up front
then the battery distribution tie point would be
on the cross-feed contactor. With the configuration
you've described, then the starter contactor becomes
the tie point.
>If so, I also assume I would run appropriate sized wire ~8-10 awg (but not
>the heavy 2awg) from aux bat side of the XFEED to the Aux bus and use same
>wire to from the aux alt (prob 8 amp b&C alternator).
Oops . . . sounds like you're describing a Z-14
architecture using an SD-8 on the aux side. Not
recommended due to aux battery contactor loads being
such a significant portion of the SD-8's output.
Suggest a Z-13 architecture is more appropriate to
maximizing the capabilities of the SD-8.
>Hope this makes sense. Really just trying to understand if I can only run
>two fat wires from the batteries to the firewall if I want to ground at
>the firewall or need to pull the extra "hot fat wire".
Let's talk about your architecture and choices
of hardware to fill the various slots. What
shortcomings do you perceive with a Z-13 architecture
that drives you toward dual batteries?
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 3
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| Subject: | "Chubby" wires and fuseblocks |
>Comments/Questions: I dont' undestand how to connect large current loads
>to FASTON fuse blocks.
>
>Max wire into FASTON seems to be #10
>
>Fuses up 30A are sold by B&C
>
>Most #10 wire is not rated for 30A.
I don't know of any #10 wire that is not rated for
30A in airplanes.
>What am I missing?
>
I don't recommend any fuses beyond 14AWG/15A be used
in the fuse blocks. What systems are you wiring
that demand the use of larger wire/fuses?
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 4
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>Comments/Questions: Hi Bob,
>
>Re: S700-2-10 switch
>
>What is the current rating for this switch?
The S700 series switches are Carling G-series devices.
The data sheet for this line of products may be reviewed
at:
http://www.aeroelectric.com/Mfgr_Data/Switches/Carling_G-series.pdf
Note that these are rated at up to 20A in 120VAC systems.
In the article at:
http://aeroelectric.com/articles/Switch_Ratings.pdf
we explore the simple ideas behind current ratings
and service life of switches as installed in various
working environments.
>I would like to use this switch to turn on rotating beacons (12 amps) and
>strobe lights (11 amps) using the circuit in figure 11-18 (page 11-19) in
>the 11th edition of your book. The B&C catalog lists the rating as '15VAC
>maximum'. How does this rating apply to a 14 volt system?
>My application would run 23 amps through the switch. Will the switch
>handle this load?
Yes, you'll probably get a satisfactory service life
using the S700-2-10 for this application. But I'm curious
as to where you got these current values. I'm also curious
as to why you have a combination of strobes and rotating
beacons on the same airplane.
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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Mark,
Here is the link to the grommet info:
http://www.spaenaur.ca/pdf/sectionJ/J69.pdf
The grommets are not all the same size, but most are 315-263. So the
groove diameter is 7/16 and I would have drilled 27/64" holes.
I think the ribs are 6061-T6 32 thou.
Unfortunately, I have a bad cold, so I won't be able to visit the
hangar to take photos. If you held a grommet in your fingers and
sliced it vertically with a dull knife, tearing as well as cutting,
that's what they look like.
I pushed the grommets in when it was about freezing temperature, but
they were still quite pliable. They were not difficult to install
using just my fingers. It didn't run any wire or conduit in them,
just left them there. The frame of the wing is rivetted, but the
skins are not on it yet. It is just sitting on the workbench.
As long as the SBR material is considered aviation quality, I expect I
just need larger holes.
Jeff
> Time: 09:21:58 AM PST US
> From: <Flagstone@cox.net>
> Subject: Re: AeroElectric-List: Grommets
>
> Your finding has me concerned. Could you provide the following details:
>
> 1 Grommet Dimensions or Spaenaur part #:
> Inside Diameter
> Groove Diameter
> Outside Diameter
> Groove Width
> Overall Thickness
>
> 2 Hole Diameter
>
> 3 Rib thickness
>
> Were the wires in conduit? If so what was the outside diameter of the
> conduit.
>
> Do you have a pic of the installed grommet and the split grommet you can
> post?
Message 6
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rob(at)hyperion-ef.com wrote:
> While not disputing that the grommets failed, I must question your
> explanation. The coefficient of thermal expansion for aluminum alloy 3003
> (a common sheet alloy) is 12.9 microinch/inch deg F, so doing the math for a
> 1 inch diameter hole and a temperature change from a really hot 100 deg F
> day for installation and a really cold minus 50 deg F day during the winter
> you get a worst case diameter change of slightly less than .002 inch. A
> half inch diameter hole would change less than .001 inch for the same
> temperature change.
>
> Installing the grommets into an undersize hole, thus stressing the grommet,
> is probably the culprit, not contraction alone.
>
>
> Best regards,
>
> Rob Housman
> Irvine, CA
> Europa XS Tri-Gear
> A070
> Airframe complete
>
> --
Rob - I think you're using the coefficient for the aluminum and then computing
the change based on the size of the hole. The change in hole size is because of
the change in the aluminum size. 1" or 1/2" hole doesn't matter - only the amount
of aluminum around the hole!
Actually, as the aluminum cools wouldn't it contract, making the hole bigger? The
temperature would have to rise so the aluminum expands to make the hole smaller.
My opinion is the bushings got brittle and maybe had flaws or residual stresses
that made them break. I doubt change in hole diameter had anything to do with
it.
John
--------
John Dalman
Elburn, IL
RV-8 N247TD
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=177406#177406
Message 7
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Jeff:
That's all I need to work with. Thanks
Hope you feel better
Mark
----- Original Message -----
From: "Jeff Page" <jpx@Qenesis.com>
Sent: Thursday, April 17, 2008 6:14 AM
Subject: AeroElectric-List: Re: Grommets
>
> Mark,
>
> Here is the link to the grommet info:
> http://www.spaenaur.ca/pdf/sectionJ/J69.pdf
> The grommets are not all the same size, but most are 315-263. So the
> groove diameter is 7/16 and I would have drilled 27/64" holes.
> I think the ribs are 6061-T6 32 thou.
> Unfortunately, I have a bad cold, so I won't be able to visit the
> hangar to take photos. If you held a grommet in your fingers and
> sliced it vertically with a dull knife, tearing as well as cutting,
> that's what they look like.
> I pushed the grommets in when it was about freezing temperature, but
> they were still quite pliable. They were not difficult to install
> using just my fingers. It didn't run any wire or conduit in them,
> just left them there. The frame of the wing is rivetted, but the
> skins are not on it yet. It is just sitting on the workbench.
>
> As long as the SBR material is considered aviation quality, I expect I
> just need larger holes.
>
> Jeff
>
>> Time: 09:21:58 AM PST US
>> From: <Flagstone@cox.net>
>> Subject: Re: AeroElectric-List: Grommets
>>
>> Your finding has me concerned. Could you provide the following details:
>>
>> 1 Grommet Dimensions or Spaenaur part #:
>> Inside Diameter
>> Groove Diameter
>> Outside Diameter
>> Groove Width
>> Overall Thickness
>>
>> 2 Hole Diameter
>>
>> 3 Rib thickness
>>
>> Were the wires in conduit? If so what was the outside diameter of the
>> conduit.
>>
>> Do you have a pic of the installed grommet and the split grommet you can
>> post?
>
>
>
>
>
>
>
Message 8
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On Thu, 17 Apr 2008 07:03:17 -0700
"Bubblehead" <jdalman2000@yahoo.com> wrote:
<snip>
>
>
> Rob - I think you're using the coefficient for the aluminum and then computing
the change based on the size of the hole. The change in hole size is because
of the change in the aluminum size. 1" or 1/2" hole doesn't matter - only the
amount of aluminum around the hole!
>
> Actually, as the aluminum cools wouldn't it contract, making the hole bigger?
The temperature would have to rise so the aluminum expands to make the hole smaller.
>
> My opinion is the bushings got brittle and maybe had flaws or residual stresses
that made them break. I doubt change in hole diameter had anything to do with
it.
>
> John
>
> --------
> John Dalman
> Elburn, IL
> RV-8 N247TD
>
>
Hi John,
When you're looking at the dimensional change in the material, you have
to look at the overall dimensions of the item. Say you have a piece of
aluminum 10 inches X 10 inches with a 1 inch dia hole in the center.
If a drop in temperature causes the material to shrink 0.001 inch per
inch (just to pick a number), the new dimensions will be 10 thousandths
less or 9.99 X 9.99 and the inside hole will be .999 inches in dia.
The size of the internal hole will be the same as if the material was
still there.
Bob W.
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/cables/
Message 9
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Jeff,
Just a guess but exposure to solvents could breakdown SBR. I cannot
imagine that hole size alone is the issue.
http://www.alliedrubber.com/Gasket/SBRRubber.cfm.htm
"When exposed to petroleum derivatives, the performance of this rubber is
inferior to many other synthetics. Red SBR rubber is popular for use as a
gasket in low pressure applications such as washers and gaskets for the
heating and plumbing trades. Black SBR is commonly used for abrasion
conditions such as skirtboard and chute lining."
Ralph & Laura Hoover
RV7A N527LR
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jeff Page
Sent: Wednesday, April 16, 2008 10:53 AM
Subject: AeroElectric-List: Grommets
I was surprised to find halves of grommets lying on the floor of my
hangar the other day. In January, they were installed in the leading
edge ribs. It has been too cold here in Toronto to do much work on my
plane since then.
As far as I can tell, the holes in the aluminum ribs shrunk from the
cold and cut the grommets in half. I am glad I found this out before
pulling all the wires through !
The holes were drilled a hair smaller than the grommets, which fit
nicely without bunching up. The holes were carefully deburred and I
can rotate my finger in the holes without feeling a sharp edge.
The grommets I purchased from Spaenaur rather than the local hardware
store. They are specd as material: SBR, hardness: 60 durometer +/-5.
Are these grommets the wrong material ?
Should there be slack around the grommet when fitted in the hole ?
Some other problem I haven't thought of ?
Thanks,
Jeff Page
Dream Aircraft Tundra #10
Message 10
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I'm glad to hear that I wasn't the only student that did not fall asleep in
freshman physics lecture.
Best regards,
Rob Housman
Irvine, CA
Europa XS Tri-Gear
A070
Airframe complete
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob White
Sent: Thursday, April 17, 2008 7:51 AM
Subject: Re: AeroElectric-List: Re: Grommets
On Thu, 17 Apr 2008 07:03:17 -0700
"Bubblehead" <jdalman2000@yahoo.com> wrote:
<snip>
>
>
> Rob - I think you're using the coefficient for the aluminum and then
computing the change based on the size of the hole. The change in hole size
is because of the change in the aluminum size. 1" or 1/2" hole doesn't
matter - only the amount of aluminum around the hole!
>
> Actually, as the aluminum cools wouldn't it contract, making the hole
bigger? The temperature would have to rise so the aluminum expands to make
the hole smaller.
>
> My opinion is the bushings got brittle and maybe had flaws or residual
stresses that made them break. I doubt change in hole diameter had anything
to do with it.
>
> John
>
> --------
> John Dalman
> Elburn, IL
> RV-8 N247TD
>
>
Hi John,
When you're looking at the dimensional change in the material, you have
to look at the overall dimensions of the item. Say you have a piece of
aluminum 10 inches X 10 inches with a 1 inch dia hole in the center.
If a drop in temperature causes the material to shrink 0.001 inch per
inch (just to pick a number), the new dimensions will be 10 thousandths
less or 9.99 X 9.99 and the inside hole will be .999 inches in dia.
The size of the internal hole will be the same as if the material was
still there.
Bob W.
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/cables/
Message 11
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Heat makes the hole bigger. Haven't you ever had to remove a stubborn bolt?
That is done with a torch to make the hole bigger.
Bryan
----- Original Message -----
From: "Rob Housman" <rob@hyperion-ef.com>
Sent: Thursday, April 17, 2008 1:35 PM
Subject: RE: AeroElectric-List: Re: Grommets
> <rob@hyperion-ef.com>
>
> I'm glad to hear that I wasn't the only student that did not fall asleep
> in
> freshman physics lecture.
>
>
> Best regards,
>
> Rob Housman
> Irvine, CA
> Europa XS Tri-Gear
> A070
> Airframe complete
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob
> White
> Sent: Thursday, April 17, 2008 7:51 AM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Re: Grommets
>
>
> On Thu, 17 Apr 2008 07:03:17 -0700
> "Bubblehead" <jdalman2000@yahoo.com> wrote:
>
> <snip>
>>
>>
>> Rob - I think you're using the coefficient for the aluminum and then
> computing the change based on the size of the hole. The change in hole
> size
> is because of the change in the aluminum size. 1" or 1/2" hole doesn't
> matter - only the amount of aluminum around the hole!
>>
>> Actually, as the aluminum cools wouldn't it contract, making the hole
> bigger? The temperature would have to rise so the aluminum expands to make
> the hole smaller.
>>
>> My opinion is the bushings got brittle and maybe had flaws or residual
> stresses that made them break. I doubt change in hole diameter had
> anything
> to do with it.
>>
>> John
>>
>> --------
>> John Dalman
>> Elburn, IL
>> RV-8 N247TD
>>
>>
> Hi John,
>
> When you're looking at the dimensional change in the material, you have
> to look at the overall dimensions of the item. Say you have a piece of
> aluminum 10 inches X 10 inches with a 1 inch dia hole in the center.
> If a drop in temperature causes the material to shrink 0.001 inch per
> inch (just to pick a number), the new dimensions will be 10 thousandths
> less or 9.99 X 9.99 and the inside hole will be .999 inches in dia.
> The size of the internal hole will be the same as if the material was
> still there.
>
>
> Bob W.
>
>
> --
> N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> 3.8 Hours Total Time and holding
> Cables for your rotary installation - http://roblinstores.com/cables/
>
>
> --
> Checked by AVG.
> 9:00 AM
>
>
Message 12
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| Subject: | Thermal expansion (was Grommets) |
Listers,
The link below provides info. applicable to the conversation.
http://hyperphysics.phy-astr.gsu.edu/Hbase/thermo/thexp2.html#c1
Raymond Julian
Kettle River, MN
"Hope for the best,
but prepare for the worst."
Message 13
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| Subject: | Re: Rear Mounted Batteries - more questions |
Bob,
Thanks for the response and heres some more details....
building a rv10, dual grt hx, 430w, sl30, tt - ap, lycoming io540 - one lightspeed
ignition and one mag. Will have basic airspeed round gauges for backup...
ie groudspeed, vsi, altimeter and an electric gyro attitude indicator. Have
similar systems in RV7A except dynon not grt, no sl30 and all both mags.
Why two batteries...primarily rumblings on those with efis to the need to have
the two batteries in starting to keep from resetting the boot-up operation of
the efis's during engine startup (honestly, unverified by me). Adding an extra
battery is an insignificant expense (relatively speaking). Having two batteries
would make me more comfortable with dual electronic ignition in the future.
I won't start that way as engine already ordered and configured but it's much
easier to plumb for future than redo later.
>
> Hmmmm . . . normally we'd like to see the cross-feed contactor
> mounted on the firewall. This provides nice fat-wire terminals
> from both batteries to serve as distribution points for the
> two batteries in addressing their respective tasks.
>
In a previous post on the original thread you stated....
>
> Quote:
>
> The crossfeed contactor, starter contactor and current limiter
> block can be mounted within inches of each other and "wired" with
> flat strap like the pictures found in this directory . . .
>
> http://www.aeroelectric.com/Pictures/Wiring_Technique/
>
> The short straps are much easier to fabricate and install than
> very short hunks of fat wire with terminals.
>
> Bob . . .
>
So I'm a little confused. Maybe I took this one out of context and was specifically
directed at firewall mounted batteries.
I've actually already ran the two 2awg fat wires to the front where I could mount
the xfeed contactor but then found the above post and thought maybe it should
only be one.
I'm on the road this week but will review the z13 tomorrow night. Maybe all I
need and don't need the extra complexity.
Thanks again,
Doug
--------
Doug
"Fools" are always more creative than process people and will always
find ways to ruin a perfectly good set of processes.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=177495#177495
Message 14
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| Subject: | A Bit of Help, Please |
I am installing Whelen LED taxi/recognition lights.
Each one draws 0.9 amps.
I am using an DPDT on-off-on switch to operate them. One position for
steady on, one for flashing. I want to use only one switch instead of two.
I'm using Eric Jones' wig wag flasher for the recognition mode.
For the flash switch selection, I've wired one side with leads from the
flasher module that activate the flash.
For the steady on switch selection, I've wired power through the other side
of the switch.
When in flash mode, to keep power from going back through the wires and
causing the lights to stay on constantly, I've added zener diodes.
The diodes are Radio Shack 12v INT4742A. The package says the
characteristics are current = 21mA and max power dissipation = 1.0W.
I've tested the lights with the diodes in the power wires for 45 minutes
without a problem.
My question is - Are these diodes sufficient for long term use with lights
drawing 0.9 Amps?
Thanks in advance,
Stan Sutterfield
**************Need a new ride? Check out the largest site for U.S. used car
listings at AOL Autos.
(http://autos.aol.com/used?NCID=aolcmp00300000002851)
Message 15
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| Subject: | Re: A Bit of Help, Please |
Buy the right ones rated for your load and sleep at night.
If you cannot afford it, contact me off list and I will mail you a couple :)
Joe Motis
No archivos amigo
**************Need a new ride? Check out the largest site for U.S. used car
listings at AOL Autos.
(http://autos.aol.com/used?NCID=aolcmp00300000002851)
Message 16
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| Subject: | Questions on avionics |
4/17/2008
Hello Ira,
1) You wrote: "There is no requirement for TSO in owner built aircraft."**
2) FAR SEC 91.217 Says:
"Data correspondence between automatically reported pressure
altitude data and the pilot's altitude reference.
No person may operate any automatic pressure altitude reporting equipment
associated with a radar beacon transponder-
(a) When deactivation of that equipment is directed by ATC;
(b) Unless, as installed, that equipment was tested and calibrated to
transmit altitude data corresponding within 125 feet (on a 95 percent
probability basis) of the indicated or calibrated datum of the altimeter
normally used to maintain flight altitude, with that altimeter referenced to
29.92 inches of mercury for altitudes from sea level to the maximum
operating altitude of the aircraft; or
(c) Unless the altimeters and digitizers in that equipment meet the
standards of TSO-C10b and TSO-C88, respectively."
3) Please explain, with specific valid reference, why the phrase "No person
may ..." seen above would not apply to a person flying an amateur built
experimental aircraft.
4) You are correct that there are alternatives to using TSO'd equipment,
when such equipment is specifically required by a regulation, provided that
you can prove to the FAA's satisfaction that your alternative equipment is
acceptable to the FAA. Here is how you go about doing that:
FAR Sec. 21.609 "Approval for deviation.
(a) Each manufacturer who requests approval to deviate from any performance
standard of a TSO shall show that the standards from which a deviation is
requested are compensated for by factors or design features providing an
equivalent level of safety.
(b) The request for approval to deviate, together with all pertinent data,
must be submitted to the Manager of the Aircraft Certification Office for
the geographic area in which the manufacturer is located. If the article is
manufactured in another country, the request for approval to deviate,
together with all pertinent data, must be submitted through the civil
aviation authority in that country to the FAA."
Obtaining an approval for deviation is not a trivial task and none of the
manufacturers of non TSO'd altitude encoders contained in their EFIS units
have done so to my knowledge.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
**PS: This statement is also not correct when it comes to the ELT installed,
if one is required by FAR Sec 91.207, in an amateur built experimental
aircraft.
-----------------------------------------------------------------
Time: 04:30:41 AM PST US
Subject: Re: Questions on avionics
From: "rampil" <ira.rampil@gmail.com>
Re: TSO and altimetry sources
There is no requirement for TSO in owner built aircraft. As I said
previously, there is only a performance requirement.
Part 23 is a separate issue.
--------
Ira N224XS
Message 17
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| Subject: | pinout for Softcom ATC-P intercom?? |
Can anyone point me to an installation manual (or just the pin IDs of
the dB25) for a Softcom ATC-P intercom?
I thought there was a collection of installation diagrams on the
Aeroelectric site, but I've been unable to locate it.
Thanks,
Charlie
Message 18
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| Subject: | Re: A Bit of Help, Please |
At 08:39 PM 4/17/2008 -0400, you wrote:
>I am installing Whelen LED taxi/recognition lights.
>Each one draws 0.9 amps.
>I am using an DPDT on-off-on switch to operate them. One position for
>steady on, one for flashing. I want to use only one switch instead of two.
>I'm using Eric Jones' wig wag flasher for the recognition mode.
>For the flash switch selection, I've wired one side with leads from the
>flasher module that activate the flash.
>For the steady on switch selection, I've wired power through the other
>side of the switch.
>When in flash mode, to keep power from going back through the wires and
>causing the lights to stay on constantly, I've added zener diodes.
>The diodes are Radio Shack 12v INT4742A. The package says the
>characteristics are current = 21mA and max power dissipation = 1.0W.
>I've tested the lights with the diodes in the power wires for 45 minutes
>without a problem.
>My question is - Are these diodes sufficient for long term use with lights
>drawing 0.9 Amps?
>Thanks in advance,
>Stan Sutterfield
It's not clear as to why you selected Zener diodes for this
task. Zeners are for voltage regulation . . . and it seems
that the task you're describing uses the diodes to prevent
reverse current flow under some conditions. Now, if you've
used a 1N4742 zener in the forward biased mode to replace
a simple rectifier diode, then the current ratings stated
for zener operation do not apply. A 1N4742 forward biased
zener is probably good for about an amp . . . but in the
reverse direction, the condition that you want the current
to be zero, the 12 zener mode of operation will kick in and
it will cause the difference between your 14v system and the
12v rating of the zener to be impressed across parts of the
system that you want to be completely 'cold'.
See:
http://www.aeroelectric.com/Pictures/Misc/RS_Diodes.jpg
The smallest diode suited to the task would be the
1N4001 offered as RS catalog number 276-1101. However,
higher voltage ratings don't hurt a thing so any of the
1N400-series devices could be used.
My personal preference for mechanical robustness are
the 1N5400-series, 3 amp devices. Again, having a part
that is electrically "too big" isn't a factor for your
application. These diodes are about 3x the size
and have more robust bodies and leadwires. These are
the diodes shown in this picture:
http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg
When we were selling this assembly, the fatter diodes
were selected for ease of assembly and robustness.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 19
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| Subject: | Re: Transponder for sale (mode S) |
Ernest Christley wrote:
> <echristley@nc.rr.com>
>
> Michael Pereira wrote:
>> <mjpereira68@gmail.com>
>>
>> I don't really understand this. The cost of avionics is because of the
>> low volume and the liability costs. Implementing Linux isn't going to
>> cut the costs more than 20 bucks on a device. This is a huge deduction
>> for something like a wifi router. It's noise if you're talking about a
>> device like a garmin 430.
>>
>
> The point wasn't that the OLPC uses Linux. The point was that the
> technology to implement a self configuring mesh network is both cheap
> and widespread. The point was that the people in charge think of
> $3,000 as "low cost", while the same task is being done for <$200.
>
> I realize that Garmin has to make a few pennies. I'm also an
> engineer, and I like to eat, too. But I don't expect the government
> to legislate that everyone by a Cisco C6500 to use the internet. That
> sort of equipment is just way overkill for the job. To say that the
> industry should pursue a technology direction that forces everyone to
> buy expensive equipment, when the same job can be performed...neigh,
> is being performed...by much cheaper equipment so that someone can
> make some money is a broken window argument.
>
> Part of the problem is the low volume, as you claim. And so they
> propose a system that will perpetuate the need to use low volume
> devices? All that would be required to implement the design goals
> that I've seen is a white-box GPS, the innards of a PalmVx, and a
> medium strength transceiver. The software is trivial, considering the
> number of examples with open source available (ie, the hard part is
> done already). There's nothing in the mix that would push a
> marginally successful product into the $3,000 range.
>
> I think most people involved with aircraft are jaded to the point they
> truly believe everything should cost thousands. You have not, because
> you ask not.
>
I'm running a bit behind on emails.
Hi Earnest,
You're right, of course. Anyone notice the activity on the RV list & the
VAF forum about APRS? Take a look at Sam Buchanan's installation.
http://home.hiwaay.net/~sbuc/journal/tracker.htm
The whole setup is only a couple hundred bucks; for a few hundred more,
you could receive & display the info directly in the cockpit. These
things do basically everything that ADS-B does, plus a little more. The
low wattage xmitter (all you need) would fit in the base of a
streamlined antenna, with just power & serial data lines coming in the
cockpit. In fact, a dedicated antenna on the top of the plane could
contain the GPS rcvr & need nothing but power.
Charlie
Message 20
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| Subject: | Re: Questions on avionics |
bakerocb@cox.net wrote:
>
> 4/17/2008
>
> Hello Ira,
>
> 1) You wrote: "There is no requirement for TSO in owner built
> aircraft."**
>
> 2) FAR SEC 91.217 Says:
>
> "Data correspondence between automatically reported pressure
> altitude data and the pilot's altitude reference.
>
> No person may operate any automatic pressure altitude reporting equipment
> associated with a radar beacon transponder-
>
> (a) When deactivation of that equipment is directed by ATC;
>
> (b) Unless, as installed, that equipment was tested and calibrated to
> transmit altitude data corresponding within 125 feet (on a 95 percent
> probability basis) of the indicated or calibrated datum of the altimeter
> normally used to maintain flight altitude, with that altimeter
> referenced to
> 29.92 inches of mercury for altitudes from sea level to the maximum
> operating altitude of the aircraft; or
>
> (c) Unless the altimeters and digitizers in that equipment meet the
> standards of TSO-C10b and TSO-C88, respectively."
>
> 3) Please explain, with specific valid reference, why the phrase "No
> person may ..." seen above would not apply to a person flying an
> amateur built experimental aircraft.
I don't understand why you think what he said is wrong.
No person may operate any automatic pressure altitude reporting
equipment ...Unless.... that equipment was tested and calibrated...;
or...that equipment meet the standards of TSO-C10b and TSO-C88
There's an OR statement there. One, the other, or both can be true, and
the statement is still true (I'm a Software Engineer by training, so I
took a special class just for that sort of reasoning 8*)
--
http://www.ronpaultimeline.com
Message 21
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| Subject: | Questions on avionics |
I would argue that you are not looking for a deviation to the TSO you
are looking to comply with the standard of the TSO without a formal
proof.
Mike
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
bakerocb@cox.net
Sent: Thursday, April 17, 2008 6:51 PM
ira.rampil@gmail.com
Subject: AeroElectric-List: Questions on avionics
4/17/2008
Hello Ira,
1) You wrote: "There is no requirement for TSO in owner built
aircraft."**
2) FAR SEC 91.217 Says:
"Data correspondence between automatically reported pressure
altitude data and the pilot's altitude reference.
No person may operate any automatic pressure altitude reporting
equipment
associated with a radar beacon transponder-
(a) When deactivation of that equipment is directed by ATC;
(b) Unless, as installed, that equipment was tested and calibrated to
transmit altitude data corresponding within 125 feet (on a 95 percent
probability basis) of the indicated or calibrated datum of the altimeter
normally used to maintain flight altitude, with that altimeter
referenced to
29.92 inches of mercury for altitudes from sea level to the maximum
operating altitude of the aircraft; or
(c) Unless the altimeters and digitizers in that equipment meet the
standards of TSO-C10b and TSO-C88, respectively."
3) Please explain, with specific valid reference, why the phrase "No
person
may ..." seen above would not apply to a person flying an amateur built
experimental aircraft.
4) You are correct that there are alternatives to using TSO'd equipment,
when such equipment is specifically required by a regulation, provided
that
you can prove to the FAA's satisfaction that your alternative equipment
is
acceptable to the FAA. Here is how you go about doing that:
FAR Sec. 21.609 "Approval for deviation.
(a) Each manufacturer who requests approval to deviate from any
performance
standard of a TSO shall show that the standards from which a deviation
is
requested are compensated for by factors or design features providing an
equivalent level of safety.
(b) The request for approval to deviate, together with all pertinent
data,
must be submitted to the Manager of the Aircraft Certification Office
for
the geographic area in which the manufacturer is located. If the article
is
manufactured in another country, the request for approval to deviate,
together with all pertinent data, must be submitted through the civil
aviation authority in that country to the FAA."
Obtaining an approval for deviation is not a trivial task and none of
the
manufacturers of non TSO'd altitude encoders contained in their EFIS
units
have done so to my knowledge.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
**PS: This statement is also not correct when it comes to the ELT
installed,
if one is required by FAR Sec 91.207, in an amateur built experimental
aircraft.
-----------------------------------------------------------------
Time: 04:30:41 AM PST US
Subject: Re: Questions on avionics
From: "rampil" <ira.rampil@gmail.com>
Re: TSO and altimetry sources
There is no requirement for TSO in owner built aircraft. As I said
previously, there is only a performance requirement.
Part 23 is a separate issue.
--------
Ira N224XS
10/2/2007 11:10 AM
10/2/2007 11:10 AM
Message 22
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| Subject: | Questions on avionics |
Read the regulation. It says that the 'encoder' must meet the TSO
standards. It doesn't say that it must be TSO'd. That is a subtle
legal difference.
Mike
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Ernest Christley
Sent: Thursday, April 17, 2008 7:51 PM
Subject: Re: AeroElectric-List: Questions on avionics
<echristley@nc.rr.com>
bakerocb@cox.net wrote:
>
> 4/17/2008
>
> Hello Ira,
>
> 1) You wrote: "There is no requirement for TSO in owner built
> aircraft."**
>
> 2) FAR SEC 91.217 Says:
>
> "Data correspondence between automatically reported pressure
> altitude data and the pilot's altitude reference.
>
> No person may operate any automatic pressure altitude reporting
equipment
> associated with a radar beacon transponder-
>
> (a) When deactivation of that equipment is directed by ATC;
>
> (b) Unless, as installed, that equipment was tested and calibrated to
> transmit altitude data corresponding within 125 feet (on a 95 percent
> probability basis) of the indicated or calibrated datum of the
altimeter
> normally used to maintain flight altitude, with that altimeter
> referenced to
> 29.92 inches of mercury for altitudes from sea level to the maximum
> operating altitude of the aircraft; or
>
> (c) Unless the altimeters and digitizers in that equipment meet the
> standards of TSO-C10b and TSO-C88, respectively."
>
> 3) Please explain, with specific valid reference, why the phrase "No
> person may ..." seen above would not apply to a person flying an
> amateur built experimental aircraft.
I don't understand why you think what he said is wrong.
No person may operate any automatic pressure altitude reporting
equipment ...Unless.... that equipment was tested and calibrated...;
or...that equipment meet the standards of TSO-C10b and TSO-C88
There's an OR statement there. One, the other, or both can be true, and
the statement is still true (I'm a Software Engineer by training, so I
took a special class just for that sort of reasoning 8*)
--
http://www.ronpaultimeline.com
10/2/2007 11:10 AM
10/2/2007 11:10 AM
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