Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

GRT Panel Layout
Goto page Previous 1, 2, 3

Matronics Email Lists Forum Index -> RV10-List

View previous topic :: View next topic

Author Message

dave.saylor.aircrafters(a
Guest

Posted: Sat May 26, 2012 3:19 pm Post subject: GRT Panel Layout

According to Mid-Continent, turn coordinators run between .28 and .35

amp (brushless vs. ...brushed? brushful?).



I use a TCW power supply to backup my GPS/Comm, Autopilot, and trim.

With any sort of power burble in IMC, I intend to immediately declare

an emergency and get to VMC before I loose Comm and AP.  That doesn't

cover the "sudden and complete all-electronics failure", so hopefully

the TC and mechanical instruments would help out there.



Since transmitting is probably my biggest backup power draw, and trim

depends on conditions, so it's pretty hard to say how long the power

would last.



Dave Saylor

831-750-0284 CL

On Fri, May 25, 2012 at 9:42 PM, Bob Turner <bobturner(at)alum.rpi.edu> wrote:

 	  Quote: 	
		   



 For the VFR vs IFR (but in VMC) debate, don't forget the third option: Â file IFR and if the controller won't allow your requested deviation, ask for VFR on top at 500' above your altitude, assuming you are in VMC. Controller will be happy because he's relieved of separation responsibility; you'll be happy because you're still in the system, so if the weather goes below VFR just call them up to get back to a "real" IFR clearance. This also works to avoid routing you don't want. Of course you need VMC.



 As to the partial panel question: yes I think it can be done, but:

 In this emergency have you also lost pitch trim? (no power?). Flying pp without pitch trim is a handful. I think you'd have to fly the approach at unusually high speed, whatever indicated speed the plane was trimmed for when power was lost.

 Also, Murphy's law dictates that this failure will happen in turbulence, where the TC will be rocking back and forth, you'll need to average by eye. I think the basic roll stability of the -10 is just sufficient for this, I wouldn't want to be forced to do it in an RV-7.



 Does anyone know the current draw of a typical turn coordinator? Is it feasible to run it off a small backup battery for, say, two hours?



 --------

 Bob Turner

 RV-10 QB





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=373984#373984

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Sat May 26, 2012 9:12 pm Post subject: Re: GRT Panel Layout

If there's any question of how long the backup battery will last, I'd skip the radio call. It might cost you 15 minutes of TC time. Turn off all the radios; turn on the nav and check position as needed.



I've practiced flying a VOR approach with no radios except a handheld nav/com. The com makes you feel warm and fuzzy but is useless. The VOR is what you want. A handheld aviation GPS is even better.



With all the talk about lightning's effect on avionics, I'm more worried about its effect on me. Inside a metal cage I'm pretty safe. But with the upper half of my body surrounded by non-conducting fiberglass, I wonder if the lightning's path of least resistance would't be thru my salt water filled body!

_________________
Bob Turner
RV-10 QB

bill.peyton

Joined: 19 Sep 2010
Posts: 198
Location: St. Louis, MO

Posted: Tue May 29, 2012 3:34 am Post subject: Re: GRT Panel Layout

Have you planned on static wicks?  If you are really going to plan on IFR, IMHO they are a must.  I had both comms fail in the clouds prior to installing them on my current plane.  After 19 years, I have never since had an issue.  I am planning on installing them on our current RV-10 project.  



I agree with Robin, I went through the failure mode analysis, and the steam gauges are not really necessary.  Use a Dynon D6 or such and free up some space.  It comes with an internal backup battery that will last you well over an hour.  Put it on the left side were you have the AH.  



I don't understand your comment regarding trim issues and using the VPX-pro.  I have the VPX setup, and I have the trim running through the VPX.  The only issue I could see would be a total VPX failure, which would kill the trim servo.  The VPX has the stuck switch feature and will allow operation of the trim from the EFIS.

_________________
Bill
WA0SYV
Aviation Partners, LLC

napolin(at)me.com
Guest

Posted: Tue May 29, 2012 7:46 am Post subject: GRT Panel Layout

Hi Bill



I am not sure about static wicks at this time.  I wont be painting the aircraft until about a year after I start flying which is hopefully this fall so I have some time to decide.



As far as the VPX, itdoes a great job protecting you from a relay failure as its not only solid state with the higher reliability but its using the equivalent of two "relays" in series with both having to commend a trim change for it to occur.  



As far as switch failure, I think the timed activation feature provide by another vendor is better.  The VPX literature states that for switch failure all you have to do is give opposite trim and the trim motor will stop.  Well if the switch is broken maybe its stuck and wont operate in the opposite direction.  So I would have to realize I have a runway trim then try opposite trim, and if that doesnt work go for the copilot stick or try to bring up the menues in the VPX to shut the trim off as the forces on the stick are getting larger and larger.   Doesnt sound like a good plan to me and by the time it gets turned off I will probably be at max trim condition.I prefer a trim off switch on the panel, no thinking necessary.  I dont want to get to the max trim condition to begin with, the fact that I can bring the trim back to neutral after the max trim condition occurs is nice but not sufficient by itself.



Nikolaos Napoli



On May 29, 2012, at 7:34 AM, "bill.peyton" <peyton.b(at)sbcglobal.net> wrote:



 	  Quote: 	
		   

 

 Have you planned on static wicks?  If you are really going to plan on IFR, IMHO they are a must.  I had both comms fail in the clouds prior to installing them on my current plane.  After 19 years, I have never since had an issue.  I am planning on installing them on our current RV-10 project.  

 

 I agree with Robin, I went through the failure mode analysis, and the steam gauges are not really necessary.  Use a Dynon D6 or such and free up some space.  It comes with an internal backup battery that will last you well over an hour.  Put it on the left side were you have the AH.  

 

 I don't understand your comment regarding trim issues and using the VPX-pro.  I have the VPX setup, and I have the trim running through the VPX.  The only issue I could see would be a total VPX failure, which would kill the trim servo.  The VPX has the stuck switch feature and will allow operation of the trim from the EFIS.

 

 --------

 Bill 

 WA0SYV

 Aviation Partners, LLC

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=374142#374142

mmayfield

Joined: 09 Oct 2009
Posts: 40
Location: NSW Central Coast, Australia

Posted: Tue May 29, 2012 2:34 pm Post subject: Re: GRT Panel Layout

The risks of lightning strike causing multiple panel failures of glass equipment in an all-metal plane like an RV are extremely low. Your fuel tank is more likely to explode, in which case your instruments are the least of your worries!  



The beauty of a properly constructed metal-skinned plane is that the electric charge stays in the highly conductive aluminium until it exits back to the atmosphere an instant later. They might flicker briefly, but having been hit by lightning multiple times in a big aircraft, I've never seen a glass instrument fail. They barely skip a heartbeat (more than I can say for myself!)



"Glass" redundancy is the norm for the big jets now. They generally have a backup PFD, much like the Trutrak "Gemini", which is totally independently powered.



Cheers

_________________
Mike

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Tue May 29, 2012 3:21 pm Post subject: Re: GRT Panel Layout

Mike,



I agree with your post, except that the -10 is not an "all metal" plane. The top half - including where my head resides - is non-conducting fiberglass. I would hope a lightning strike on the cabin top would find the path of least resistance down the center post. But if the strike is off center it might think my body is the way to go!

_________________
Bob Turner
RV-10 QB

bill.peyton

Joined: 19 Sep 2010
Posts: 198
Location: St. Louis, MO

Posted: Tue May 29, 2012 3:56 pm Post subject: Re: GRT Panel Layout

Nick,

With the VPX system, when it detects a stuck switch, it disables the mechanical switch.  It then allows trim operation directly from a soft switch 

on the EFIS



Bob, I am wishing I had buried some mesh in the exterior glass.  I have heard that is common for the lancairs

_________________
Bill
WA0SYV
Aviation Partners, LLC

napolin(at)me.com
Guest

Posted: Tue May 29, 2012 6:37 pm Post subject: GRT Panel Layout

Hey Bill,



Maybe I am missing something but I dont think the VPX can detect a stuck switch.  I don't believe it has a way to detect if a switch is on because you are commanding it or its on because its stuck, it also has no timer to detect how long a switch has been on.  It fact I don't think there is a way to detect that at all.  It has no circuitry inside the switch, so all it knows is the switch is on or off.  If you know otherwise please point me to the pertinent section in the manual.



Thanks

Niko

On May 29, 2012, at 7:56 PM, bill.peyton wrote:



 	  Quote: 	
		   

 

 Nick,

 With the VPX system, when it detects a stuck switch, it disables the mechanical switch.  It then allows trim operation directly from a soft switch 

 on the EFIS

 

 --------

 Bill 

 WA0SYV

 Aviation Partners, LLC

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=374222#374222

napolin(at)me.com
Guest

Posted: Tue May 29, 2012 7:33 pm Post subject: GRT Panel Layout

Mike,

Extremely low risk is a relative term.



I don't know how you have reached that conclusion but I don't think its true.  On non-certified equipment its anyones guess as to how tolerant these computers are to lightning  As I have stated earlier, I believe your statement is true for large cockpits with certified equipment, i.e. airliners, but not true for the small craft we are flying.  There are document cases in RVs where lightning took out the EFIS, there are also document cases of damage to instruments due to lightning in many aircraft.



Niko

On May 29, 2012, at 6:34 PM, mmayfield wrote:



 	  Quote: 	
		   

 

 The risks of lightning strike causing multiple panel failures of glass equipment in an all-metal plane like an RV are extremely low. Your fuel tank is more likely to explode, in which case your instruments are the least of your worries! [Shocked] 

 

 The beauty of a properly constructed metal-skinned plane is that the electric charge in the highly conductive aluminium until it exits back to the atmosphere an instant later. They might flicker briefly, but having been hit by lightning multiple times in a big aircraft, I've never seen a glass instrument fail. They barely skip a heartbeat (more than I can say for myself!)

 

 "Glass" redundancy is the norm for the big jets now. They generally have a backup PFD, much like the Trutrak "Gemini", which is totally independently powered.

 

 Cheers

 

 --------

 Mike

 

 Your political opinions are noted. And ignored.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=374218#374218

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Tue May 29, 2012 8:03 pm Post subject: GRT Panel Layout

If you know anything about the electrical standard DO-160, most of the 

non-TSO EFIS meet this DO-160 standard which is the same as TSO 

electronics meet. It is a standard as to withstanding voltage spikes and 

other system disruptions. I really don't see that the size of the 

cockpit has anything to do with it, since the length of electrical path 

has little to do with transmission of a lightning discharge.

On 5/29/2012 8:32 PM, Nikolaos Napoli wrote:

 	  Quote: 	

 Mike,

 Extremely low risk is a relative term.

 I don't know how you have reached that conclusion but I don't think its true.  On non-certified equipment its anyones guess as to how tolerant these computers are to lightning  As I have stated earlier, I believe your statement is true for large cockpits with certified equipment, i.e. airliners, but not true for the small craft we are flying.  There are document cases in RVs where lightning took out the EFIS, there are also document cases of damage to instruments due to lightning in many aircraft.

 Niko

 On May 29, 2012, at 6:34 PM, mmayfield wrote:

> 

>

> The risks of lightning strike causing multiple panel failures of glass equipment in an all-metal plane like an RV are extremely low. Your fuel tank is more likely to explode, in which case your instruments are the least of your worries! [Shocked]

>

> The beauty of a properly constructed metal-skinned plane is that the electric charge in the highly conductive aluminium until it exits back to the atmosphere an instant later. They might flicker briefly, but having been hit by lightning multiple times in a big aircraft, I've never seen a glass instrument fail. They barely skip a heartbeat (more than I can say for myself!)

>

> "Glass" redundancy is the norm for the big jets now. They generally have a backup PFD, much like the Trutrak "Gemini", which is totally independently powered.

>

> Cheers

>

> --------

> Mike

>

> Your political opinions are noted. And ignored.

>

>

> Read this topic online here:

>

> http://forums.matronics.com/viewtopic.php?p=374218#374218

>

>

-----

No virus found in this message.

Checked by AVG - www.avg.com

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

mmayfield

Joined: 09 Oct 2009
Posts: 40
Location: NSW Central Coast, Australia

Posted: Tue May 29, 2012 10:32 pm Post subject: Re: GRT Panel Layout

 	  napolin(at)me.com wrote: 	
		  Mike,

Extremely low risk is a relative term.



I don't know how you have reached that conclusion but I don't think its true. 	


I reached that conclusion because although there may have been RVs hit by lightning I'm not aware of any which have been "brought down" by it, or where pilots have been fried by it. This fact leads me to conclude that the chances of a lightning strike causing your premature demise while you're out flying are very low.  

 	  Quote: 	
		  On non-certified equipment its anyones guess as to how tolerant these computers are to lightning  As I have stated earlier, I believe your statement is true for large cockpits with certified equipment, i.e. airliners, but not true for the small craft we are flying.  	


I disagree. If the uncertified equipment from certain manufacturers is not at least crafted with fault-tolerant design principles and DO160 in mind, I'd be a little disappointed and openly wonder why they're inflicting it on the OBAM community (and why people are buying it).

 	  Quote: 	
		  There are document cases in RVs where lightning took out the EFIS, there are also document cases of damage to instruments due to lightning in many aircraft. 	


I guess my whole point is: how far do you want to take this? I mean, fighter pilots don't have metal roofs over their heads either. I've known of accidents where the pilot has been killed by a birdstrike, a "tree" strike, a heart attack, GLOC, even by the ricochet of their own explosive ordnance, but never a lightning strike, even though aircraft get hit now and again. From the instrument perspective, backup basic flight instruments of some form (electronic or otherwise) are essential for sure, with an independent power supply of course. But how far do you want to take it, and where does the redundancy itself become redundant?



Cheers,

_________________
Mike

jesse(at)saintaviation.co
Guest

Posted: Wed May 30, 2012 3:38 am Post subject: GRT Panel Layout

The VPX does have a timer for how long a switch has been pressed. It will disable that circuit if a switch is pressed for more than a preset length of time, at which time you can control the circuit (trim or flaps) from the screen.

Jesse Saint

Saint Aviation, Inc.

jesse(at)saintaviation.com

C: 352-427-0285

F: 815-377-3694

On May 29, 2012, at 10:36 PM, Nikolaos Napoli wrote:

 	  Quote: 	

 Hey Bill,

 Maybe I am missing something but I dont think the VPX can detect a stuck switch.  I don't believe it has a way to detect if a switch is on because you are commanding it or its on because its stuck, it also has no timer to detect how long a switch has been on.  It fact I don't think there is a way to detect that at all.  It has no circuitry inside the switch, so all it knows is the switch is on or off.  If you know otherwise please point me to the pertinent section in the manual.

 Thanks

 Niko

 On May 29, 2012, at 7:56 PM, bill.peyton wrote:

> 

> 

> Nick,

> With the VPX system, when it detects a stuck switch, it disables the mechanical switch.  It then allows trim operation directly from a soft switch 

> on the EFIS

> 

> --------

> Bill 

> WA0SYV

> Aviation Partners, LLC

> 

> 

> 

> 

> Read this topic online here:

> 

> http://forums.matronics.com/viewtopic.php?p=374222#374222

> 

> 

> 

> 

> 

> 

> 

> 

> 

>

napolin(at)me.com
Guest

Posted: Wed May 30, 2012 4:02 am Post subject: GRT Panel Layout

Here is a handbook on lightning from NASA and industry.  It was specifically geared for small aircraft.

http://www.niar.twsu.edu/agate/Documents/Lightning/WP3.1-031027-043.pdfIt 

An interesting quote from it   "it is also important to note that many strike incidents have been reported where no bona fide thunderstorms have been visually observed or reported "

As far as RV's being brought down by lightning, not many hours have been accumulated in rv's with experimental EFIS's and no vacuum artificial horizons in IMC condition.  Until recently, most small aircraft flying in IMC had vacuum systems, and even certified EFIS systems that are in certified aircraft like Cessnas with G1000 have vacuum systems.  A lightning strike or other phenomena taking the instrument panel out on these aircraft is not a catastrophic event and will not get reported.  The same event, in an all electric, experimental EFIS aircraft might be a different story.  I do not know how tolerant my EFIS is to lightening strike,   I have no information, therefore, I don't assume, I work around it.

Another point is that if a person loses control in IMC and crashes due to lightning strike taking out their all electric panel I don't think it would be reported as such or one would even find out.  There are many loss of control in IMC accidents that are not explained.  So there really isn't much data on this at all to base a conclusion on.

As for the fiberglass roof on the RV10, I personally have a bunch of wires including coaxial cable running above my head.  Don't know how much it helps but that small risk would take a lot of effort to mitigate I am not willing to do it.

How far do I want to take this?  Simple for me, by installing a vacuum system I mitigate this risk for relatively small effort and cost.  I don't have to figure out the unknowns. Don't have to assume.   Its simple, its been proven over decades, its cheap, it works when the lights go out.  It fits my risk mitigation criteria.   So yes, the risk is low and so is the effort to guard against it.  Its like seat belts, the risk of me getting into an accident while driving to work today is extremely low, but putting on my seat belt to make the accident more survivable is not much of an effort.  



On May 30, 2012, at 2:32 AM, mmayfield wrote:

 	  Quote: 	
		  --> RV10-List message posted by: "mmayfield" <mmayfield(at)ozemail.com.au (mmayfield(at)ozemail.com.au)>

napolin(at)me.com wrote:

 	  Quote: 	
		  Mike,

Extremely low risk is a relative term.



I don't know how you have reached that conclusion but I don't think its true. 

	


I reached that conclusion because although there may have been RVs hit by lightning I'm not aware of any which have been "brought down" by it, or where pilots have been fried by it. This fact leads me to conclude that the chances of a lightning strike causing your premature demise while you're out flying are very low. [Wink] 



 	  Quote: 	
		  On non-certified equipment its anyones guess as to how tolerant these computers are to lightning  As I have stated earlier, I believe your statement is true for large cockpits with certified equipment, i.e. airliners, but not true for the small craft we are flying.  

	


I disagree. If the uncertified equipment from certain manufacturers is not at least crafted with fault-tolerant design principles and DO160 in mind, I'd be a little disappointed and openly wonder why they're inflicting it on the OBAM community (and why people are buying it).



 	  Quote: 	
		  There are document cases in RVs where lightning took out the EFIS, there are also document cases of damage to instruments due to lightning in many aircraft.

	


I guess my whole point is: how far do you want to take this? I mean, fighter pilots don't have metal roofs over their heads either. I've known of accidents where the pilot has been killed by a birdstrike, a "tree" strike, a heart attack, GLOC, even by the ricochet of their own explosive ordnance, but never a lightning strike, even though aircraft get hit now and again. From the instrument perspective, backup basic flight instruments of some form (electronic or otherwise) are essential for sure, with an independent power supply of course. But how far do you want to take it? 	




Cheers,



--------

Mike



Your political opinions are noted. And ignored.





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=374245#374245



         - The RV10-List   -->             &n========================<b            -                         &nbs  --> ========================





[/quote]

napolin(at)me.com
Guest

Posted: Wed May 30, 2012 4:12 am Post subject: GRT Panel Layout

I don't think thats true Jesse.  I have personally asked him about incorporating a 3 second limit at Sun-n-Fun. He said that it could be incorporated but he didn't seem too enthusiastic about it.  He said "3 seconds is a long time."   If enough people ask for it he might incorporate it in future revisions of the software.  If you know otherwise please point me to the location where it states that.

Thanks

On May 30, 2012, at 7:36 AM, Jesse Saint wrote:

 	  Quote: 	

 The VPX does have a timer for how long a switch has been pressed. It will disable that circuit if a switch is pressed for more than a preset length of time, at which time you can control the circuit (trim or flaps) from the screen.

 Jesse Saint

 Saint Aviation, Inc.

 jesse(at)saintaviation.com

 C: 352-427-0285

 F: 815-377-3694

 On May 29, 2012, at 10:36 PM, Nikolaos Napoli wrote:

> 

> 

> Hey Bill,

> 

> Maybe I am missing something but I dont think the VPX can detect a stuck switch.  I don't believe it has a way to detect if a switch is on because you are commanding it or its on because its stuck, it also has no timer to detect how long a switch has been on.  It fact I don't think there is a way to detect that at all.  It has no circuitry inside the switch, so all it knows is the switch is on or off.  If you know otherwise please point me to the pertinent section in the manual.

> 

> Thanks

> Niko

> 

> 

> On May 29, 2012, at 7:56 PM, bill.peyton wrote:

> 

>> 

>> 

>> Nick,

>> With the VPX system, when it detects a stuck switch, it disables the mechanical switch.  It then allows trim operation directly from a soft switch 

>> on the EFIS

>> 

>> --------

>> Bill 

>> WA0SYV

>> Aviation Partners, LLC

>> 

>> 

>> 

>> 

>> Read this topic online here:

>> 

>> http://forums.matronics.com/viewtopic.php?p=374222#374222

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

>> 

> 

> 

> 

> 

>

jesse(at)saintaviation.co
Guest

Posted: Wed May 30, 2012 4:30 am Post subject: GRT Panel Layout

You are right. That was a feature that they advertised early in the company, where the flaps or trim would cancel if pressed for 15 seconds or something like that. Now, it tells you when the trim or flaps are running, and pushing the opposite switch for 3 seconds will disable that circuit. They apparently replaced the feature I was talking about with the above, as well as disabling all trims and flaps if a switch is active during boot-up.  I will request that feature too, as I thought I had it already.

Jesse Saint

Saint Aviation, Inc.

jesse(at)saintaviation.com

C: 352-427-0285

F: 815-377-3694

On May 30, 2012, at 8:11 AM, Nikolaos Napoli wrote:

 	  Quote: 	

 I don't think thats true Jesse.  I have personally asked him about incorporating a 3 second limit at Sun-n-Fun. He said that it could be incorporated but he didn't seem too enthusiastic about it.  He said "3 seconds is a long time."   If enough people ask for it he might incorporate it in future revisions of the software.  If you know otherwise please point me to the location where it states that.

 Thanks

 On May 30, 2012, at 7:36 AM, Jesse Saint wrote:

> 

> 

> The VPX does have a timer for how long a switch has been pressed. It will disable that circuit if a switch is pressed for more than a preset length of time, at which time you can control the circuit (trim or flaps) from the screen.

> 

> Jesse Saint

> Saint Aviation, Inc.

> jesse(at)saintaviation.com

> C: 352-427-0285

> F: 815-377-3694

> 

> On May 29, 2012, at 10:36 PM, Nikolaos Napoli wrote:

> 

>> 

>> 

>> Hey Bill,

>> 

>> Maybe I am missing something but I dont think the VPX can detect a stuck switch.  I don't believe it has a way to detect if a switch is on because you are commanding it or its on because its stuck, it also has no timer to detect how long a switch has been on.  It fact I don't think there is a way to detect that at all.  It has no circuitry inside the switch, so all it knows is the switch is on or off.  If you know otherwise please point me to the pertinent section in the manual.

>> 

>> Thanks

>> Niko

>> 

>> 

>> On May 29, 2012, at 7:56 PM, bill.peyton wrote:

>> 

>>> 

>>> 

>>> Nick,

>>> With the VPX system, when it detects a stuck switch, it disables the mechanical switch.  It then allows trim operation directly from a soft switch 

>>> on the EFIS

>>> 

>>> --------

>>> Bill 

>>> WA0SYV

>>> Aviation Partners, LLC

>>> 

>>> 

>>> 

>>> 

>>> Read this topic online here:

>>> 

>>> http://forums.matronics.com/viewtopic.php?p=374222#374222

>>> 

>>> 

>>> 

>>> 

>>> 

>>> 

>>> 

>>> 

>>> 

>>> 

>> 

>> 

>> 

>> 

>> 

> 

> 

> 

> 

> 

>

Kelly McMullen

Joined: 16 Apr 2008
Posts: 1188
Location: Sun Lakes AZ

Posted: Wed May 30, 2012 6:02 am Post subject: GRT Panel Layout

Maybe not a lot of initial labor effort, but you are looking at approx. $5-600 in vacuum system, $700 for vacuum art. horizon, both of which have 500 mean time before failure estimates, at which time you get to spend another $1000 replacing them, along with more labor to clean the lines of carbon dust, along with annual filter changes. Not exactly low cost or low effort in the long run. More money and effort if you elect to use more reliable wet vacuum pump over a dry pump. Or you could spend about the same money for a backup EFIS that likely will last 4 times longer (or more) than the vacuum pump items.

 Kelly



On Wed, May 30, 2012 at 5:02 AM, Nikolaos Napoli <napolin(at)me.com (napolin(at)me.com)> wrote:

 	  Quote: 	
		   

How far do I want to take this?  Simple for me, by installing a vacuum system I mitigate this risk for relatively small effort and cost.  I don't have to figure out the unknowns. Don't have to assume.   Its simple, its been proven over decades, its cheap, it works when the lights go out.  It fits my risk mitigation criteria.   So yes, the risk is low and so is the effort to guard against it.  Its like seat belts, the risk of me getting into an accident while driving to work today is extremely low, but putting on my seat belt to make the accident more survivable is not much of an effort.  

 





 



 



On May 30, 2012, at 2:32 AM, mmayfield wrote:

 	  Quote: 	
		   --> RV10-List message posted by: "mmayfield" <mmayfield(at)ozemail.com.au (mmayfield(at)ozemail.com.au)>



napolin(at)me.com wrote:

  	  Quote: 	
		  Mike,

Extremely low risk is a relative term.



I don't know how you have reached that conclusion but I don't think its true. 

 	




I reached that conclusion because although there may have been RVs hit by lightning I'm not aware of any which have been "brought down" by it, or where pilots have been fried by it. This fact leads me to conclude that the chances of a lightning strike causing your premature demise while you're out flying are very low. [Wink] 

 

 	  Quote: 	
		  On non-certified equipment its anyones guess as to how tolerant these computers are to lightning  As I have stated earlier, I believe your statement is true for large cockpits with certified equipment, i.e. airliners, but not true for the small craft we are flying.  

 	




I disagree. If the uncertified equipment from certain manufacturers is not at least crafted with fault-tolerant design principles and DO160 in mind, I'd be a little disappointed and openly wonder why they're inflicting it on the OBAM community (and why people are buying it). 



 	  Quote: 	
		  There are document cases in RVs where lightning took out the EFIS, there are also document cases of damage to instruments due to lightning in many aircraft.

	




I guess my whole point is: how far do you want to take this? I mean, fighter pilots don't have metal roofs over their heads either. I've known of accidents where the pilot has been killed by a birdstrike, a "tree" strike, a heart attack, GLOC, even by the ricochet of their own explosive ordnance, but never a lightning strike, even though aircraft get hit now and again. From the instrument perspective, backup basic flight instruments of some form (electronic or otherwise) are essential for sure, with an independent power supply of course. But how far do you want to take it? 	


 

Cheers,



--------

Mike



Your political opinions are noted. And ignored.





Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=374245#374245

 

         - The RV10-List   -->             &n========================



	


[b]

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor
KCHD

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Wed May 30, 2012 12:15 pm Post subject: Re: GRT Panel Layout

Risk analysis is a tricky business, because everything effects everything else. For example, you might encounter a microburst - one that you could have out-climbed except for the extra weight, and slight HP loss, of a vacuum pump. Or the pump's shear shaft could fail to shear when it was supposed to, and a vane breakage and pump jam lead to internal damage and failure of the engine. Or, the finite lifetime of vacuum pumps leads to more frequent work around the engine. Every once in a while the gasket is forgotten, or defective, or over or under torqued, resulting in loss of engine oil and engine seizure. Or the mechanic just leaves a wrench on top of the engine, causing mayhem later.



Very low probabilities, for sure. But so, apparently are lightning strikes. With such low statistics it's very hard to say for certain that one approach is more risk adverse than another. But my opinion - just my 2 cents - is that maintenance activities introduce risk, more than lightning does (at least as long as you make an effort to avoid the latter). In point of fact, I think GA would be slightly safer if airframes were only inspected every other year (for aircraft flying less than some amount, say, 300 hours). I think annuals cause more problems than they find. (I'd advocate looking at the engine every year).

_________________
Bob Turner
RV-10 QB

Display posts from previous:

	Matronics Email Lists Forum Index -> RV10-List	All times are GMT - 8 Hours Goto page Previous 1, 2, 3
Page 3 of 3

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum