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IMC - What If???
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gmcjetpilot

Joined: 04 Nov 2006
Posts: 170

Posted: Fri Sep 26, 2008 5:15 am Post subject: IMC - What If???

Good point about lighting and agree, but 

  one fine point. Most static and ground 

  straps help the airframe more than 

  avionics. You need to isolate the avionics 

  from the airframe and feed it with a 

  truly isolated interrupt power supply. 

   

  Most "homebuilt" EFIS don't have to meet 

  any specs but many do try to have at least 

  a regulated power supply. That is good to 

  protect the expensive parts in the main box 

  but may sacrifice it self in a surge. 

   

  Bottom line it goes dark.

   

  Lighting is an amazing and powerful force 

  that we have scratched the surface. I have 

   been a pilot of planes that have been hit 

  by lighting from a small twin (aerostar) 

  to large twins B737. Each time damage was 

  done but to the  airframe not the avionics. 

  Not saying that will be the case every 

  time, just my experience.

   

  The day will come that a EFIS causes a GA 

  accident in IMC. There have been plenty from 

  vacuum pumps, so its not shocker the risk is there.

  

 	  Quote: 	
		  From: RobHickman(at)aol.com (RobHickman(at)aol.com)

Subject: Re: IMC - What If??? 

  >Bruce(at)glasair.org writes:
	


  >What's gonna happen when you're up there 

  >and a  lighting bolt strikes your RV and 

  >fries all your electrical  systems?

  

 	  Quote: 	
		  Without ground straps on your control 

  >surfaces and static wicks your 
	


  >electronics could be the least of your 

  >problems.  Actually  we spent a lot of 

  >time with the help of Crossbow designing 

  >in lightning   protection on the 

  >electrical connections that wire to the 

  >EFIS. Crossbow has  extensive experience 

  >with passing the lightning protection 

  >requirements for certification. We have 

  >not actually done lightning verification 

  >testing of our EFIS or the RV-10. 



           [quote][b]

RobHickman(at)aol.com
Guest

Posted: Fri Sep 26, 2008 7:18 am Post subject: IMC - What If???

In a message dated 9/26/2008 6:17:04 A.M. Pacific Daylight Time,  gmcjetpilot(at)yahoo.com writes:

  	  Quote: 	
		     Most "homebuilt" EFIS don't have to meet 

   any specs but many do try to have at least 

   a regulated power supply. That is good to 

   protect the expensive parts in the main box 

   but may sacrifice it self in a surge. 

    

   Bottom line it goes dark.

	


 

 The AFS internal Lithium battery powers the system after the protected  regulated power supply.  If a voltage spike takes out the regulator the  screen will not go dark until the battery run's down, usually over an  hour.

  

 Rob Hickman

 Advanced Flight Systems



Looking for simple solutions to your real-life financial challenges? Check out WalletPop for the latest news and information, tips and calculators.

  [quote][b]

khorton01(at)rogers.com
Guest

Posted: Fri Sep 26, 2008 11:18 am Post subject: IMC - What If???

RobHickman(at)aol.com wrote:

 	  Quote: 	
		    

 In a message dated 9/26/2008 6:17:04 A.M. Pacific Daylight Time,  

 gmcjetpilot(at)yahoo.com writes:



 Most "homebuilt" EFIS don't have to meet 

 any specs but many do try to have at least 

 a regulated power supply. That is good to 

 protect the expensive parts in the main box 

 but may sacrifice it self in a surge. 

  

 Bottom line it goes dark.



 The AFS internal Lithium battery powers the system after the protected  

 regulated power supply.  If a voltage spike takes out the regulator the  screen 

 will not go dark until the battery run's down, usually over an  hour.

  



   


	


Has the ability of the EFIS to remain powered after a lightning strike 

been validated by any HIRF/lightning testing, or is it purely 

hypothetical?  Lots of stuff that looks good on paper fails when 

subjected to testing.



Kevin Horton



-- 

Kevin Horton

RV-8 (Flight Test Phase)

Ottawa, Canada

http://www.kilohotel.com/rv8

RobHickman(at)aol.com
Guest

Posted: Fri Sep 26, 2008 1:24 pm Post subject: IMC - What If???

In a message dated 9/26/2008 12:20:58 P.M. Pacific Daylight Time,  khorton01(at)rogers.com writes:

  	  Quote: 	
		  Has the    ability of the EFIS to remain powered after a lightning strike 

been    validated by any HIRF/lightning testing, or is it purely    

hypothetical?  Lots of stuff that looks good on paper fails when    

subjected to testing. 	
 You must have not read my original response,  

 

 

 

   In a message dated 9/25/2008 4:55:37 P.M. Pacific Daylight Time, RobHickman  writes:

  	  Quote: 	
		     

Actually    we spent a lot of time with the help of Crossbow designing in lightning    protection on the electrical connections that wire to the EFIS. Crossbow has    extensive experience with passing the lightning protection requirements for    certification.  We have not    actually done lightning verification testing of our EFIS or the    RV-10. 	






Looking for simple solutions to your real-life fi382257x1200540686/aol?redir=http://www.walletpop.com/?NCID=emlcntuswall086/aol?redir=http://www.walletpop.com/?NCID=emlcntuswall00000001" target="_blank">Check out WalletPop for the latest news and information, tips and calculators.

  [quote][b]

Bruce(at)glasair.org
Guest

Posted: Fri Sep 26, 2008 6:56 pm Post subject: IMC - What If???

Just remember, with a non TSO'd EFIS, you  and your family are the Beta testers.

  

  

  

Bruce 

www.Glasair.org 

<?xml:namespace prefix = o ns =  "urn:schemas-microsoft-com:office:office" /> 

 [quote]   

   --

Bret Smith

Joined: 09 Jan 2006
Posts: 178
Location: Mineral Bluff, GA

Posted: Fri Sep 26, 2008 7:33 pm Post subject: IMC - What If???

Bruce,

  

 Following your rationale,  anyone who flies a non-certificated aircraft is a Beta tester... I fail to  accept your premise.

  

 Bret Smith

 RV-9A N16BL

 Blue Ridge, Ga

 www.FlightInnovations.com

  



   From: owner-rv-list-server(at)matronics.com  [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Bruce  Gray

Sent: Friday, September 26, 2008 10:55 PM

To:  rv-list(at)matronics.com

Subject: RE: IMC - What  If???

 

 Just remember, with a non TSO'd EFIS, you  and your family are the Beta testers.

  

  

  

Bruce 

www.Glasair.org 

 

 [quote]   

   --

_________________
Bret Smith
RV-9A (Emp)

Bruce(at)glasair.org
Guest

Posted: Fri Sep 26, 2008 9:07 pm Post subject: IMC - What If???

Yes, to a degree. I built my Glasair III,  you built your RV-9. We both know how it was done and the care and pride we took  in it. 

  

 I didn't write the code in my EHSI or your  EFIS. I have no idea of the care or competence that went into it. Meeting TSO  specs is one way to gage that level. Finding a bunch of pilots willing to bet  their lives on it and fly it around for several thousand hours is another. No  thanks, I'll pass.

  

  

  

Bruce 

www.Glasair.org 

 

 [quote]   

   --

ronlee(at)pcisys.net
Guest

Posted: Sat Sep 27, 2008 5:06 am Post subject: IMC - What If???

Actually  Bret he is right.  I read about one guy (RV I think) who  had

 two  different EFIS systems (different makers).  He was in IMC and  

 maybe on  approach or setting up for approach the main one quit  functioning

 properly.  The other one worked.  I don't recall the specifics  but it may have 

 been a  software/database issue.

  

 Ron  Lee

  

  

 Bruce,

 [quote]    

   Following your    rationale, anyone who flies a non-certificated aircraft is a Beta tester... I    fail to accept your premise.

    

   Bret Smith

   RV-9A N16BL

   Blue Ridge, Ga

   www.FlightInnovations.com

    



   

 

   

   Just remember, with a non TSO'd EFIS, you    and your family are the Beta testers.

    

    

      

Bruce   

www.Glasair.org

[b]

Bruce(at)glasair.org
Guest

Posted: Sat Sep 27, 2008 5:44 am Post subject: IMC - What If???

Yes, it was a GRT EFIS that locked up  because a runway was not selected before a vector to final was initiated. He had  another Dyon that kept working. He used his AP as the tie breaker. Said it was  the most terrifying 10 minutes of his life.

  

 Bruce

  

www.Glasair.org 

 

 [quote]   

   --

RobHickman(at)aol.com
Guest

Posted: Sat Sep 27, 2008 7:56 am Post subject: IMC - What If???

In a message dated 9/26/2008 7:58:03 P.M. Pacific Daylight Time,  Bruce(at)glasair.org writes:

  	  Quote: 	
		     Just remember, with a non TSO'd EFIS, you    and your family are the Beta testers.

	


 

  

Just  because it is TSO'd does not mean it will not fail or have software  issues.  Last spring I borrowed the new factory Glasair Sportsman with  dual AFS EFIS's for two months.  We absolutely loved the  plane and flew it for over 50 hours, including a trip to San  Francisco.  We only had two problems  in the 50 hours that we flew it.   The first problems started after the software in the TSOâ€™d Garmin 430W  was updated causing the screen to wash out and disappear in flight.  The second problem happened after we  entered the Class B airspace on our San Francisco trip,  after about 5 minutes of silence (not  much traffic today in the Bay Area?) We noticed that the TSOâ€™d 430W had failed  at the worst possible time.  The  radio was sent back to Garmin for repair and it worked great, until it failed  again on Glasairâ€™s trip to Sun-n-Fun. 

Anything  can and will have problems,  you need to have the proper training so that  you can recognize and handle the failure. 

  

 The following is from:  [url=http://www.alexisparkinn.com/nwpilot\'s_tranatlantic_flight.htm]http://www.alexisparkinn.com/nwpilot's_tranatlantic_flight.htm[/url]

  

Then, the G1000 started to go nuts, with the fuel  indicators displaying red X's.  Next, I received a CO2 detector failure,  then GPS-1 failure!  At this point I was thinking "What next!?"  

Well, I didn't have to wait long: The G1000 display  suddenly went black,  with white text in the left hand corner saying  "initializing system"!  

(Note: All this was happening at night, locked in the  soup, at FL070 and 200+ miles from the nearest land --  with almost no  communication with a ground-based person!)  

 



Looking for simple solutions to your real-life financial challenges? Check out WalletPop for the latest news and information, tips and calculators.

  [quote][b]

robertrv607(at)yahoo.com
Guest

Posted: Sat Sep 27, 2008 10:17 am Post subject: IMC - What If???

Kevin: Would be interesting to hear from EFIS People... on this I will call them

          next week to hear what the have to say, as to what is the test they do on

          their products...and what  is the record of failures as of now...

  

          Bert



--- On Fri, 9/26/08, Kevin Horton <khorton01(at)rogers.com> wrote:



  	  Quote: 	
		  From: Kevin Horton <khorton01(at)rogers.com>

Subject: Re: IMC - What If???

To: rv-list(at)matronics.com

Date: Friday, September 26, 2008, 3:14 PM



 	  Quote: 	
		  --> RV-List message posted by: Kevin Horton <khorton01(at)rogers.com>



RobHickman(at)aol.com wrote:

 	  Quote: 	
		    

 In a message dated 9/26/2008 6:17:04 A.M. Pacific Daylight Time,  

 gmcjetpilot(at)yahoo.com writes:



 Most "homebuilt" EFIS don't have to meet 

 any specs but many do try to have at least 

 a regulated power supply. That is good to 

 protect the expensive parts in the main box 

 but may sacrifice it self in a surge. 

  

 Bottom line it goes dark.



 The AFS internal Lithium battery powers the system after the protected  

 regulated power supply.  If a voltage spike takes out the regulator the 

screen 
	


 	  Quote: 	
		   will not go dark until the battery run's down, usually over an  hour.

  



   


	


Has the ability of the EFIS to remain powered after a lightning strike 

been validated by any HIRF/lightning testing, or is it purely 

hypothetical?  Lots of stuff that looks good on paper fails when 

subjected to testing.



Kevin Horton



-- 

Kevin Horton

RV-8 (Flight Test Phase)

Ottawa, Canada

http://www.kilohotel.com/rv8



	
	


           [quote][b]

khorton01(at)rogers.com
Guest

Posted: Sat Sep 27, 2008 11:34 am Post subject: IMC - What If???

RobHickman(at)aol.com wrote:

 	  Quote: 	
		    

 In a message dated 9/26/2008 7:58:03 P.M. Pacific Daylight Time,  

 Bruce(at)glasair.org writes:



 Just remember, with a non TSO'd EFIS, you  and your family are the Beta 

 testers.



  

 Just  because it is TSO'd does not mean it will not fail or have software  

 issues.  Last spring I borrowed the new factory Glasair Sportsman with  dual AFS 

 EFIS's for two months.  We absolutely loved the  plane and flew it for over 

 50 hours, including a trip to San  Francisco.  We only had two problems  in the 

 50 hours that we flew it.  The first problems started after the software in 

 the TSO’d Garmin 430W  was updated causing the screen to wash out and disappear 

 in flight.  The second problem happened after we  entered the Class B 

 airspace on our San Francisco trip,  after about 5 minutes of silence (not  much 

 traffic today in the Bay Area?) We noticed that the TSO’d 430W had failed  at the 

 worst possible time.  The  radio was sent back to Garmin for repair and it 

 worked great, until it failed  again on Glasair’s trip to Sun-n-Fun. 

 Anything  can and will have problems,  you need to have the proper training 

 so that  you can recognize and handle the failure. 

  

 The following is from:  

 _http://www.alexisparkinn.com/nwpilot's_tranatlantic_flight.htm_ (http://www.alexisparkinn.com/nwpilot's_tranatlantic_flight.htm) 

  

 Then, the G1000 started to go nuts, with the fuel  indicators displaying red 

 X's.  Next, I received a CO2 detector failure,  then GPS-1 failure!  At this 

 point I was thinking "What next!?"  

 Well, I didn't have to wait long: The G1000 display  suddenly went black,  

 with white text in the left hand corner saying  "initializing system"!  

 (Note: All this was happening at night, locked in the  soup, at FL070 and 

 200+ miles from the nearest land --  with almost no  communication with a 

 ground-based person!)  

   


	


The DO-178B software development process is no iron-clad guarantee 

either. All it does is provide a higher level of confidence that the 

software was correctly coded such that is works according to the 

specification provided by the system designer. But, it provides no 

guarantee that the software specification is in fact correct. I know of 

multiple occassions where systems with DO-178B Level A (the highest 

level) software had major software faults (HUD showing pitch and bank in 

the wrong direction, fly-by-wire software crashing, etc) - not because 

of software coding errors, but because the software spec did not foresee 

all possible operating scenarios.



TSO approval and DO-178B software cert are useful benchmarks, but it is 

only with many units in service for many thousands of hours that we 

start to develope confidence that the units are trustworthy.



Assume that any device will either fail, or worse, that it will mislead 

you. This assumption is important no matter what approvals the device has.



-- 

Kevin Horton

RV-8 (Flight Test Phase)

Ottawa, Canada

http://www.kilohotel.com/rv8

khorton01(at)rogers.com
Guest

Posted: Sat Sep 27, 2008 11:45 am Post subject: IMC - What If???

Bert - there are so many different reasons that an EFIS could fail, or 

mislead you, that you should simply assume that it could occur.  This is 

true whether they have done lightning tests or not.

 

Don't bet your life on it not failing.  Have suitable backups installed, 

and be ready and capable enough (i.e. proficient to use the backups in 

real IMC conditions) to use them.



Kevin



bert murillo wrote:

 	  Quote: 	
		   Kevin: Would be interesting to hear from EFIS People... on this I will call them

          next week to hear what the have to say, as to what is the test they do on

          their products...and what  is the record of failures as of now...

  

          Bert



 --- On Fri, 9/26/08, Kevin Horton <khorton01(at)rogers.com> wrote:



 From: Kevin Horton <khorton01(at)rogers.com>

 Subject: Re: IMC - What If???

 To: rv-list(at)matronics.com

 Date: Friday, September 26, 2008, 3:14 PM



 



 RobHickman(at)aol.com wrote:

   

>  

> In a message dated 9/26/2008 6:17:04 A.M. Pacific Daylight Time,  

> gmcjetpilot(at)yahoo.com writes:

>

> Most "homebuilt" EFIS don't have to meet 

> any specs but many do try to have at least 

> a regulated power supply. That is good to 

> protect the expensive parts in the main box 

> but may sacrifice it self in a surge. 

>  

> Bottom line it goes dark.

>

> The AFS internal Lithium battery powers the system after the protected  

> regulated power supply.  If a voltage spike takes out the regulator the 

>     

 screen 

   

> will not go dark until the battery run's down, usually over an  hour.

>  

>

>   

>     



 Has the ability of the EFIS to remain powered after a lightning strike 

 been validated by any HIRF/lightning testing, or is it purely 

 hypothetical?  Lots of stuff that looks good on paper fails when 

 subjected to testing.



 Kevin Horton



   


	




-- 

Kevin Horton

RV-8 (Flight Test Phase)

Ottawa, Canada

http://www.kilohotel.com/rv8

cjensen(at)dts9000.com
Guest

Posted: Sat Sep 27, 2008 5:13 pm Post subject: IMC - What If???

One data point.  Pair of GRT EFISs in a Velocity.  410 hours, almost 10% doing some level of IFR and not as much as a hint of a glitch...of course, that says only a little bit about the likelihood of problems tomorrow, but a set of mechanical AS, Alt, TT A/P and an MCI LifeSaver w/battery backup...not interested in challenging Mother Nature or Fate.

Chuck Jensen

n395v

Joined: 10 Jan 2006
Posts: 450

Posted: Mon Sep 29, 2008 4:49 am Post subject: Re: IMC - What If???

Its not only the EFIS or its programming you need to worry about.



My F1 was all electric. 2 different EFISs.



All went black when the solenoid failed.



You need to plan backup into the sytems of the aircraft also.

_________________
Milt

Bruce(at)glasair.org
Guest

Posted: Mon Sep 29, 2008 5:07 am Post subject: IMC - What If???

That's why my ADI backup is Vacuum.



Bruce

www.Glasair.org

 

--

michele.delsol(at)microsi
Guest

Posted: Mon Sep 29, 2008 6:46 am Post subject: IMC - What If???

Thought I'd add my 2 cents - Both my AFS 3400/3500 have internal batteries,

1/2 hr each. Plus a portable VHF and a portable GPS.



Michèle

RV8 - trying to get it finished.

-----Message d'origine-----

De : owner-rv-list-server(at)matronics.com

[mailto:owner-rv-list-server(at)matronics.com] De la part de Bruce Gray

Envoyé : lundi 29 septembre 2008 15:07

À : rv-list(at)matronics.com

Objet : RE: Re: IMC - What If???






That's why my ADI backup is Vacuum.



Bruce

www.Glasair.org

 

--

Paul Valovich

Joined: 11 Jan 2006
Posts: 75

Posted: Mon Sep 29, 2008 6:49 am Post subject: IMC - What If???

Since I started this thread with what I thought was a straight-forward presentation of the analysis I used in determining my panel configuration, perhaps an addition of a not-mentioned analysis factor will provide additional fuel to this debate. That factor is the reliability of  vacuum –powered instruments in the days before glass cockpits.  

   

While the focus of recent posts has been on EFIS failure what ifs, it was my understanding that the weak link of pre-EFIS IFR flight was vacuum pump reliability. Is that a correct statement?  

   

If it is correct, then the pre-EFIS analogy to EFIS failure is IMC flight with no vacuum pump. What if???????????  

   

Seems like the challenges would be the same – establishing controlled flight in an upright attitude and having enough confidence in the tools and procedures available in that mode to get it on the ground.   

   

So what do you old guys have to say?  

Booger  

      [quote][b]

Bruce(at)glasair.org
Guest

Posted: Mon Sep 29, 2008 7:39 am Post subject: IMC - What If???

True, but  we've flown behind the standard six-pack for decades and it's failure modes are  well known and recognized. EFIS failures are more insidious and, unless the  screen goes dark, not easy to discern. 

  

 Vac pump  failure is the weak link but with proper maintenance (or a wet vac pump), system  reliability can be high.

  

  

  

Bruce 

www.Glasair.org 

 

 [quote]   

   --

chaskuss(at)yahoo.com
Guest

Posted: Mon Sep 29, 2008 9:26 am Post subject: IMC - What If???

Paul,

 Another way to improve reliability with vacuum attitude instruments is to use a "wet" vacuum pump, rather than a dry (oil-less) unit.

Charlie Kuss

--- On Mon, 9/29/08, Valovich, Paul <pvalovich(at)dcscorp.com> wrote:



 	  Quote: 	
		   From: Valovich, Paul <pvalovich(at)dcscorp.com>

 Subject: Re: IMC - What If???

 To: "rv-list(at)matronics.com" <rv-list(at)matronics.com>

 Date: Monday, September 29, 2008, 10:49 AM

 Since I started this thread with what I thought was a

 straight-forward presentation of the analysis I used in

 determining my panel configuration, perhaps an addition of a

 not-mentioned analysis factor will provide additional fuel

 to this debate. That factor is the reliability of  vacuum

 -powered instruments in the days before glass cockpits.

 

 While the focus of recent posts has been on EFIS failure

 what ifs, it was my understanding that the weak link of

 pre-EFIS IFR flight was vacuum pump reliability. Is that a

 correct statement?

 

 If it is correct, then the pre-EFIS analogy to EFIS failure

 is IMC flight with no vacuum pump. What if???????????

 

 Seems like the challenges would be the same - establishing

 controlled flight in an upright attitude and having enough

 confidence in the tools and procedures available in that

 mode to get it on the ground.

 

 So what do you old guys have to say?

 Booger

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