X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Wed, 19 Jul 2006 21:00:40 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m21.mx.aol.com ([64.12.137.2] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with ESMTP id 1283770 for lml@lancaironline.net; Wed, 19 Jul 2006 16:50:12 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.2; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m21.mx.aol.com (mail_out_v38_r7.5.) id q.420.60b347d (39952) for ; Wed, 19 Jul 2006 16:49:23 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: <420.60b347d.31eff4d3@aol.com> X-Original-Date: Wed, 19 Jul 2006 16:49:23 EDT Subject: Re: [LML] Re: VistaNav X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1153342163" X-Mailer: 9.0 Security Edition for Windows sub 5318 X-Spam-Flag: NO -------------------------------1153342163 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Egads gents, SD makes a 4Gb data card the size of a postage stamp. The computer interface treats it as a pseudo disk. Vista Nav (or anyone else) ought to be able to load such a device with program and data and allow for the shut down of the hard drive. 4 Gb ought to be enough memory and altitude would not be a factor. Are there no creative programmers left? (http://www.memoryx.net/xsd4096.html) _4GB Transcend 150x High-Speed Secure Digital Card (p/n SD-4GB-150X-TR)_ (http://www.memoryx.net/xsd4096.html) $98.99 Grayhawk In a message dated 7/19/2006 3:13:07 P.M. Central Standard Time, c177av8r@pacbell.net writes: What I did for a U2 installation (not practical here) was build a pressure vessel to house the hard disk only. Flew it above 68K several times successfully. Still have the hardware even though I haven't used it in 16-18 years. I built it in 1988 according to my autocad drawings. duane "Hamid A. Wasti" wrote: Marvin Kaye wrote: > Posted for "Tom Gourley" : > > The Inertial > Navigation Unit, one of the two boxes that makes up a complete system, > has > reasonable specs; up to 24,000 feet and operating temperature from 32F to > 105F. I would hardly call that reasonable. And 32F is the "standard atmosphere" at about 7,500 feet. 105F is essentially 40C. It is way too low for real life use. Temperatures in excess of 80C behind the panel are well documented. On a "normal" warm day of 35C, you can see temperatures well in excess to 45C in locations where you would normally install a box. Places like Phoenix routinely get over 45C in the shade during the summer. Just to put things in perspective, a box with those temperature specifications would not even get past the front door to talk to an automotive company, let alone any aviation company. > Does this mean the tablet, or Mobile Computing > Platform as it's called, will stop working above 10,000 feet. I doubt it. Wrong answer. Hard drives count on an air cushion to keep them from touching the spinning disk. The damping of the air resistance against lateral movement of the head is also taken into consideration when designing the closed loop control for positioning the head. As you get high, the air thins and both the cushion as well as the damping decrease The result is failure to seek if you are lucky, a hard crash if you are unlucky. This is not just theory, but is well documented. Also, the denser the drive, the more susceptible it is to altitude related problems. The second issue is cooling. Cooling of the CPU. Colling of the power supplies. Cooling of the graphics chip. Cooling of the backlight. Of course, you can ignore all of that and boldly press on -- many do. Maybe you will get lucky and things will work for you, maybe not. Regards, Hamid -------------------------------1153342163 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
 
 
Egads gents, SD makes a 4Gb data card the size of a postage stamp. = ;=20 The computer interface treats it as a pseudo disk.  Vista Nav (or=20 anyone else) ought to be able to load such a device with program and data an= d=20 allow for the shut down of the hard drive.    4 Gb ought to b= e=20 enough memory and altitude would not be a factor.  Are there no creativ= e=20 programmers left? 
 
 
 
Grayhawk
 
 
In a message dated 7/19/2006 3:13:07 P.M. Central Standard Time,=20 c177av8r@pacbell.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
What I did for a U2 installation (not practical here) was build a=20 pressure vessel to house the hard disk only.  Flew it above  68K= =20 several times successfully.
Still have the hardware even though I haven't used it in 16-18=20 years.  I built it in 1988 according to my autocad drawings.
duane


"Hamid A. Wasti" <hwasti@starband.net>=20 wrote:
Marvin=20 Kaye wrote:
> Posted for "Tom Gourley"=20 :
>
> The Inertial
> Navigati= on=20 Unit, one of the two boxes that makes up a complete system,
>=20 has
> reasonable specs; up to 24,000 feet and operating temperatur= e=20 from 32F to
> 105F.
I would hardly call that reasonable. And 32= F is=20 the "standard
atmosphere" at about 7,500 feet. 105F is essentially 4= 0C.=20 It is way
too low for real life use. Temperatures in excess of 80C=20 behind the
panel are well documented. On a "normal" warm day of 35C,= you=20 can see
temperatures well in excess to 45C in locations where you wo= uld=20 normally
install a box. Places like Phoenix routinely get over 45C i= n=20 the shade
during the summer. Just to put things in perspective, a bo= x=20 with those
temperature specifications would not even get past the fr= ont=20 door to
talk to an automotive company, let alone any aviation compan= y.=20

> Does this mean the tablet, or Mobile Computing
> Plat= form=20 as it's called, will stop working above 10,000 feet. I doubt it.
Wron= g=20 answer. Hard drives count on an air cushion to keep them from
touchi= ng=20 the spinning disk. The damping of the air resistance against
lateral= =20 movement of the head is also taken into consideration when
designing= the=20 closed loop control for positioning the head. As you get
high, the a= ir=20 thins and both the cushion as well as the damping
decrease The resul= t is=20 failure to seek if you are lucky, a hard crash
if you are unlucky. T= his=20 is not just theory, but is well documented.
Also, the denser the dri= ve,=20 the more susceptible it is to altitude
related problems.

The=20 second issue is cooling. Cooling of the CPU. Colling of the power=20
supplies. Cooling of the graphics chip. Cooling of the=20 backlight.

Of course, you can ignore all of that and boldly press= on=20 -- many do.
Maybe you will get lucky and things will work for you, m= aybe=20 not.

Regards,

Hamid

 
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