X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 10 Aug 2011 11:08:39 -0400 Message-ID: X-Original-Return-Path: Received: from nm20.bullet.mail.ne1.yahoo.com ([98.138.90.83] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with SMTP id 5087927 for lml@lancaironline.net; Wed, 10 Aug 2011 09:47:41 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.90.83; envelope-from=casey.gary@yahoo.com Received: from [98.138.90.56] by nm20.bullet.mail.ne1.yahoo.com with NNFMP; 10 Aug 2011 13:47:07 -0000 Received: from [98.138.89.164] by tm9.bullet.mail.ne1.yahoo.com with NNFMP; 10 Aug 2011 13:47:07 -0000 Received: from [127.0.0.1] by omp1020.mail.ne1.yahoo.com with NNFMP; 10 Aug 2011 13:47:07 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 294921.79169.bm@omp1020.mail.ne1.yahoo.com Received: (qmail 5633 invoked by uid 60001); 10 Aug 2011 13:47:07 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=eEzrC4t858/D61OHHmQuAlfbNza1DbcEFFG02FjWChW37snDifb7dI7snm57EN2nfmlfZpyu7jsW22ebQYe7RwDERYCOE5WeqN+oM+Rb4vNL3VZhqTF80tPA5wt7KQMFBKaenFtwebWVnXJIdaF3sBNlcyHa6XxG07ZllRHkxjU=; X-YMail-OSG: pB_1LoEVM1mj2feEGmkqjGERi0yg5VX0x7rtdfM.zflmmLW AoOPZmCMqvWxgtrOaXqM6u3tNy4Bh60MjmttJWNImvz7qdaYhN7Hel9Z.LcH BaOSgZpt96Z2jA2cvxLVHlpgPZ39PhKyw4ocT3n7Um25XW5sZJbC0Dvnk0Ox a90TSAl91AJtNubVKWBXLRh2LDSSnkup1iGLyaGBckbEpZ_IDgY2fdi.JaVe 5ATvbbSEG1Uquz0WAlfAetHXyGcTIA0P0FGs_KR3sIBJMCOYOvC3VLlRlVRI .pUNDu38nqWLsbqurLIGLflRROD0.HeTRcEALGDiBMxlY8E3KanALwGReZiT 1bZVr3VBoKUv.3l.LQAow7yKtRmgDgfzhskSGjqA.iUA- Received: from [173.23.189.187] by web125609.mail.ne1.yahoo.com via HTTP; Wed, 10 Aug 2011 06:47:07 PDT X-Mailer: YahooMailWebService/0.8.113.313619 References: X-Original-Message-ID: <1312984027.66140.YahooMailNeo@web125609.mail.ne1.yahoo.com> X-Original-Date: Wed, 10 Aug 2011 06:47:07 -0700 (PDT) From: Gary Casey Reply-To: Gary Casey Subject: Re: Re-doing my panel - carefully thinking through failures X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1173096422-1312984027=:66140" --0-1173096422-1312984027=:66140 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable I think there might be a difference of understanding regarding failure =0Am= odes. I don=E2=80=99t think anyone is proposing that we abandon all electr= onic devices =0Aand go back to vacuum-powered gyros. What is being propose= d by Brent (and me, I =0Asuppose) is that a vacuum-power spinning gyro is p= erhaps the most reliable =0Abackup system available. How can the =E2=80=9C= least reliable=E2=80=9D system be the =E2=80=9Cmost =0Areliable=E2=80=9D ba= ckup? Two reasons: First, the spinning gyro is not susceptible to =0Acata= strophic electrical failures (like a lightning strike) and will keep runnin= g =0Aas long as the engine is turning. Second, it is logical to limit one= =E2=80=99s thinking =0Ato =E2=80=9Csingle failure modes=E2=80=9D. In other= words the ONLY requirement of the gyro =0Asystem is that it keep working f= rom the time of the electrical failure to the =0Aearliest possible landing.= What is the likelihood that the gyro will fail in =0Athose 15 minutes? W= hat is the likelihood that the electrical system would quit =0Aand then the= engine stop turning? All this is dependent on the vacuum system =0Abeing = =E2=80=9Crequired equipment=E2=80=9D for IMC operation (if the vacuum syste= m fails on the =0Aground, it is a no-go. If it fails in the air under IMC,= it is a =E2=80=9Cland =0Aimmediately=E2=80=9D condition).=0AThe poorest ch= oice for a primary system then becomes the best choice as a =0Abackup. Log= ical, I think.=0AGary Casey =0AFrom: GT Phantom =0ASent: Tuesday, August = 09, 2011 5:55 AM =0ATo: lml@lancaironline.net =0ASubject: Re: Re: Re-doing= my panel - carefully thinking through =0Afailures Brent,=0A=0AI =0Asuppose= I should have been more specific - I assume that pilots of experimental = =0Aaircraft will exercise sufficient judgment not be flying into thundersto= rms, and =0Athus the likelihood of in-flight lightning strike is nearly nil= . Not absolutely =0Anil, naturally, but approaching or below the likelihoo= d of vacuum failure, which =0Ais fairly common. Of course, perhaps I shoul= d not make such an assumption given =0Athat a very famous pilot died just l= ast year flying his Bonanza into =0Athunderstorms.=0A=0AAbsent thunderstorm= s, we will simply have to agree to =0Adisagree. Vacuum pumps and vacuum-op= erated artificial horizons are notoriously =0Afallible, and a poor vacuum c= an give insidious symptoms causing catastrophic =0Aresults. While there ha= ve been some experimental EFIS units (notably one =0Ayou mention, also the = original pioneer Blue Mountain) which had early individual =0Afailure rates= much higher than vacuum equipment, still the likelihood of two or =0Amore = going down simultaneously is rather rare. In my personal experience my TSO= =0AGarmins failed just as often as my experimental equipment - anecdotal e= vidence, =0Ato be sure, but 3 TSO failures in 600 hrs not counting vacuum p= ump failure and =0Aattitude indicator partial failure ("lazy" attitude, "so= rt of" =0Aworking).=0A=0ANone of this absolves individuals contemplating us= e of =0Aexperimental equipment from the burden of research to draw their ow= n conclusions =0Aabout reliability.=0A=0AYour statement that TSO is require= d for legal flight =0Ais simply untrue. If you wish to dispute this, pleas= e feel free to point out =0Athe section of the FARs that you believe says o= therwise (it does not exist, but =0Aknock yourself out). I don't expect to= convince you of that; it seems that =0Athere are some folks who have made = up their minds and aren't interested in =0Aanyone else's opinion. That's f= ine, you are entitled to yours. I, like many, =0Ahave reviewed the pertine= nt FARs along with (among others) my mechanic who was a =0Achief avionics s= afety inspector for a major airline. For the type of flying for =0Awhich E= xperimental aircraft are authorized there is no such rule stating that =0Ae= ach piece of equipment must be certified to pass TSO. The altimeter must, = or =0Apass the test for equivalent accuracy (performed during the annual pi= tot-static =0Acheck). Doesn't mean it's a bad thing, only unnecessary for = legal flight. Just =0Aas you admonish people who are not engineers (I too = was a software engineer by =0Atrade) to form unwarranted opinions about avi= onics, you too should not consider =0Ayourself an expert on FARs simply bec= ause you build avionics. Glass houses, =0Aetc.=0A=0ABlocked pitot or stati= c tubes are no longer a killer for correct =0Aattitude indication on any of= the three leading experimental EFIS units (GRT, =0ADynon, MGL). May also = not be on others, haven't kept up. Of course, you will =0Anot get accurate= airspeed with either blocked and will not get accurate =0Abarometric altit= ude with static blocked, but that would happen irrespective of =0Athe type = of avionics you use. However, you will still have accurate horizon, =0Aand= GPS can provide altitude and ground speed which, combined with a pilot's = =0Aknowledge of their aircraft power settings, etc. should enable you to fl= y safely =0Ato landing. =0A=0AAt the end of the day, you are putting your o= wn life on the =0Aline. If you feel more comfortable with spinning gyros, = by all means load up. =0AHowever, if you feel you have done your research = and would rather replace that =0Avacuum pump for a second alternator to pre= vent power-out and ditch the gyro for =0Aa small self-contained backup EFIS= , then your odds of total failure will =0Aultimately be about the same - ju= st different causes.=0A=0A=0AFly =0Asafe!=0A=0ABill=0A=0A=0AOn 01/-10/-2816= 3 02:59 PM, Brent Regan wrote: =0ABill =0Aspeculates:=0A><>=0A>=0A>The =0Aprimary assumption here is false. I= t is not "given" that "two EFIS units with =0Abattery backup are more relia= ble than a single vacuum pump". Analysis and data =0Ashow the opposite is t= rue. =0A> --0-1173096422-1312984027=:66140 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
I think = there might be a difference of understanding regarding failure =0Amodes. I= don=E2=80=99t think anyone is proposing that we abandon all electronic dev= ices =0Aand go back to vacuum-powered gyros. What is being proposed by Bre= nt (and me, I =0Asuppose) is that a vacuum-power spinning gyro is perhaps t= he most reliable =0Abackup system available. How can the =E2=80=9Cleast re= liable=E2=80=9D system be the =E2=80=9Cmost =0Areliable=E2=80=9D backup? T= wo reasons: First, the spinning gyro is not susceptible to =0Acatastrophic= electrical failures (like a lightning strike) and will keep running =0Aas = long as the engine is turning. Second, it is logical to limit one=E2=80=99= s thinking =0Ato =E2=80=9Csingle failure modes=E2=80=9D. In other words th= e ONLY requirement of the gyro =0Asystem is that it keep working from the t= ime of the electrical failure to the =0Aearliest possible landing. What is= the likelihood that the gyro will fail in =0Athose 15 minutes? What is th= e likelihood that the electrical system would quit =0Aand then the engine s= top turning? All this is dependent on the vacuum system =0Abeing =E2=80=9C= required equipment=E2=80=9D for IMC operation (if the vacuum system fails o= n the =0Aground, it is a no-go. If it fails in the air under IMC, it is a = =E2=80=9Cland =0Aimmediately=E2=80=9D condition).
=0A
T= he poorest choice for a primary system then becomes the best choice as a = =0Abackup. Logical, I think.
=0A
Gary Casey
= =0A
=0A
=0A
<= /font>
=0A
=0A
From: GT Phantom
=0A
Sent: Tuesday, August 09, 2011 5:55 AM
= =0A
To: lml@lancaironline.net <= /div>=0A
Subject: Re: Re: Re-doing my panel - carefully thinking= through =0Afailures
=0A
=0A
Brent,

I =0Asuppose I s= hould have been more specific - I assume that pilots of experimental =0Aair= craft will exercise sufficient judgment not be flying into thunderstorms, a= nd =0Athus the likelihood of in-flight lightning strike is nearly nil. Not= absolutely =0Anil, naturally, but approaching or below the likelihood of v= acuum failure, which =0Ais fairly common. Of course, perhaps I should not = make such an assumption given =0Athat a very famous pilot died just last ye= ar flying his Bonanza into =0Athunderstorms.

Absent thunderstorms, w= e will simply have to agree to =0Adisagree. Vacuum pumps and vacuum-operat= ed artificial horizons are notoriously =0Afallible, and a poor vacuum can g= ive insidious symptoms causing catastrophic =0Aresults. While there have b= een some experimental EFIS units (notably one =0Ayou mention, also t= he original pioneer Blue Mountain) which had early individual =0Afailure ra= tes much higher than vacuum equipment, still the likelihood of two or =0Amo= re going down simultaneously is rather rare. In my personal experience my = TSO =0AGarmins failed just as often as my experimental equipment - anecdota= l evidence, =0Ato be sure, but 3 TSO failures in 600 hrs not counting vacuu= m pump failure and =0Aattitude indicator partial failure ("lazy" attitude, = "sort of" =0Aworking).

None of this absolves individuals contemplati= ng use of =0Aexperimental equipment from the burden of research to draw the= ir own conclusions =0Aabout reliability.

Your statement that TSO is = required for legal flight =0Ais simply untrue. If you wish to dispute this= , please feel free to point out =0Athe section of the FARs that you believe= says otherwise (it does not exist, but =0Aknock yourself out). I don't ex= pect to convince you of that; it seems that =0Athere are some folks who hav= e made up their minds and aren't interested in =0Aanyone else's opinion. T= hat's fine, you are entitled to yours. I, like many, =0Ahave reviewed the = pertinent FARs along with (among others) my mechanic who was a =0Achief avi= onics safety inspector for a major airline. For the type of flying for =0A= which Experimental aircraft are authorized there is no such rule stating th= at =0Aeach piece of equipment must be certified to pass TSO. The altimeter= must, or =0Apass the test for equivalent accuracy (performed during the an= nual pitot-static =0Acheck). Doesn't mean it's a bad thing, only unnecessa= ry for legal flight. Just =0Aas you admonish people who are not engineers = (I too was a software engineer by =0Atrade) to form unwarranted opinions ab= out avionics, you too should not consider =0Ayourself an expert on FARs sim= ply because you build avionics. Glass houses, =0Aetc.

Blocked pitot= or static tubes are no longer a killer for correct =0Aattitude indication = on any of the three leading experimental EFIS units (GRT, =0ADynon, MGL). = May also not be on others, haven't kept up. Of course, you will =0Anot get= accurate airspeed with either blocked and will not get accurate =0Abaromet= ric altitude with static blocked, but that would happen irrespective of =0A= the type of avionics you use. However, you will still have accurate horizo= n, =0Aand GPS can provide altitude and ground speed which, combined with a = pilot's =0Aknowledge of their aircraft power settings, etc. should enable y= ou to fly safely =0Ato landing.

At the end of the day, you are put= ting your own life on the =0Aline. If you feel more comfortable with spinn= ing gyros, by all means load up. =0AHowever, if you feel you have done you= r research and would rather replace that =0Avacuum pump for a second altern= ator to prevent power-out and ditch the gyro for =0Aa small self-contained = backup EFIS, then your odds of total failure will =0Aultimately be about th= e same - just different causes.


Fly =0Asafe!

Bill

=
On 01/-10/-28163 02:59 PM, Brent Regan wrote: =0A
Bill =0Aspeculates:
&l= t;<Given that two EFIS units with battery backup are more =0Areliable th= an a single vacuum pump, your argument that people must have =0A"TSO= 'd" equipment is logically ridiculous - especially if they also have= =0Aas part of their panel an independent 2-axis autopilot.>>

= The =0Aprimary assumption here is false. It is not "given" that "two EFIS u= nits with =0Abattery backup are more reliable than a single vacuum pump". A= nalysis and data =0Ashow the opposite is true.


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