X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 12 Nov 2010 16:46:21 -0500 Message-ID: X-Original-Return-Path: Received: from carbinge.com ([69.5.27.218] verified) by logan.com (CommuniGate Pro SMTP 5.3.10) with SMTP id 4576510 for lml@lancaironline.net; Fri, 12 Nov 2010 09:30:46 -0500 Received-SPF: none receiver=logan.com; client-ip=69.5.27.218; envelope-from=jbarrett@carbinge.com Received: (qmail 32302 invoked from network); 12 Nov 2010 14:30:09 -0000 X-Originating-IP: [66.235.49.247] Reply-To: From: "John Barrett" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] Re: iPad use in the cockpit X-Original-Date: Fri, 12 Nov 2010 06:30:07 -0800 X-Original-Message-ID: <012e01cb8276$1b491fc0$51db5f40$@com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_012F_01CB8233.0D25DFC0" X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: AcuCZUAqIHENe41BSjSvYc04IJYt7QAD5ueA Content-Language: en-us This is a multi-part message in MIME format. ------=_NextPart_000_012F_01CB8233.0D25DFC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable One thought about possible thermal shut down at a time when use of the gadget is crucial to safety of flight is to consider the logical = exposure to the offending conditions. =20 =20 The argument could be that when you are on an IFR flight and in IMC conditions, you likely will not have direct sunlight heating up the = cockpit. I think most of us have experienced going from sunlight to clouds at = almost any altitude and noticed how rapidly the temperature in the cockpit = drops when the greenhouse effect is lost. =20 Of course the counter argument would be that in the situation where one = is VFR on top dropping into a low IFR approach, conceivably the iPad would = not be functional in the heat generated while above the clouds and then = would not be usable for the ensuing approach even though the temperature in = the cockpit might drop rapidly. =20 Obviously, Hamd=92s recommendation to thoroughly test in all conditions = prior to relying on the iPad without a backup would be prudent. =20 =20 Regards, John Barrett =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Hamid Wasti Sent: Friday, November 12, 2010 4:29 AM To: lml@lancaironline.net Subject: [LML] Re: iPad use in the cockpit =20 The altitude and thermal specs are linked. At higher altitude, you have less air molecules to take away the heat. Because of this, a device that will heat up to a certain temperature at sea level will heat up to a higher temperature at 10,000 feet and an even higher temperature at 15,000 feet, assuming all else is equal. Put the other way, a device that will function up to a certain ambient temperature at sea level will only operate to a lower ambient temperature at 10,000 feet and an even lower ambient temperature at 15,000 feet. I do not own an iPad, so I have no personal experience. However, there have been a lot of reports about the iPad getting too hot and shutting down when exposed to direct sunlight. These are reports at ground level and some are claiming that it takes a little as 10 minutes. A Google search reveals million+ hits, including the following from cNet and Applr's own discussion forum: http://reviews.cnet.com/8301-31747_7-20001749-243.html http://discussions.info.apple.com/thread.jspa?threadID=3D2396808 &start=3D0&tstart=3D0 Quite predictably, this has led to a good ol lawsuit. Here's a news article and the actual filing: http://www.bloomberg.com/news/2010-07-26/apple-sued-over-claims-ipad-tabl= et- overheats-in-sunlight-warm-conditions.html http://www.docstoc.com/docs/document-preview.aspx?doc_id=3D48234124 The following link, claiming to answering on behalf of iPad users, acknowledges the existence of the problem and mocks people for being unreasonable for trying to use the iPad in situations where these problems can reasonably be expected to occur (their opinion of what is "reasonable"): http://www.theipadguide.com/content/books-have-better-heat-tolerance-ipad= /71 74901 I do not know if any of these reports are true, if the problems are endemic or experienced by a few outliers. What I can tell you is that whatever the experience at sea level, the thermal performance will be worse at 8,000 feet in a IV-P and worse still at 15,000 ft in a Legacy -- that is basic physics. It is your call how much credence you want to put in these reports. Whatever you decide, I would strongly urge you to thoroughly test whatever hardware/software you want to use and push it to the limit in a realistic environment before you actually put it in service. The cockpit is no place for surprises! Regards, Hamid Chris Zavatson wrote: > Thanks for all the replies. > One more question. The apple specs show maximum operating altitude of > 10,000 feet. If there is a good technical reason for this, it would > seem rather limiting for our en-route use. The operating temperature > is also kind of pushing the upper limit when on the ground on hot > summer days. The temperature issue can be somewhat controlled, but > the altitude exposure not so much. Is this a CYA or other generic = limit? > > > Environmental requirements > > * Operating temperature: 32=B0 to 95=B0 F (0=B0 to 35=B0 C) > * Nonoperating temperature: -4=B0 to 113=B0 F (-20=B0 to 45=B0 C) > * Relative humidity: 5% to 95% noncondensing > * Maximum operating altitude: 10,000 feet (3000 m) > > > Chris Zavatson > -- For archives and unsub = http://mail.lancaironline.net:81/lists/lml/List.html _____ =20 No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1153 / Virus Database: 424/3251 - Release Date: 11/11/10 ------=_NextPart_000_012F_01CB8233.0D25DFC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [LML] Re: iPad use in the = cockpit

One thought about possible thermal shut down at a time when use of = the gadget is crucial to safety of flight is to consider the logical = exposure to the offending conditions.=A0

 

The argument could be that when you are on an IFR flight and in IMC = conditions, you likely will not have direct sunlight heating up the = cockpit.=A0 I think most of us have experienced going from sunlight to = clouds at almost any altitude and noticed how rapidly the temperature in = the cockpit drops when the greenhouse effect is = lost.

 

Of course the counter argument would be that in the situation where = one is VFR on top dropping into a low IFR approach, conceivably the iPad = would not be functional in the heat generated while above the clouds and = then would not be usable for the ensuing approach even though the = temperature in the cockpit might drop rapidly.

 

Obviously, Hamd’s recommendation to thoroughly test in all = conditions prior to relying on the iPad =A0without a backup would be = prudent.=A0

 

Regards,
John Barrett

 

From:= = Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Hamid Wasti
Sent: Friday, November 12, 2010 4:29 = AM
To: lml@lancaironline.net
Subject: [LML] Re: iPad = use in the cockpit

 

The altitude and thermal specs are linked. At = higher altitude, you have
less air molecules to take away the heat. = Because of this, a device that
will heat up to a certain temperature = at sea level will heat up to a
higher temperature at 10,000 feet and = an even higher temperature at
15,000 feet, assuming all else is = equal. Put the other way, a device
that will function up to a certain = ambient temperature at sea level will
only operate to a lower ambient = temperature at 10,000 feet and an even
lower ambient temperature at = 15,000 feet.

I do not own an iPad, so I have no personal = experience. However, there
have been a lot of reports about the iPad = getting too hot and shutting
down when exposed to direct sunlight. = These are reports at ground level
and some are claiming that it takes = a little as 10 minutes. A Google
search reveals million+ hits, = including the following from cNet and
Applr's own discussion = forum:

http://re= views.cnet.com/8301-31747_7-20001749-243.html
http://discussions.info.apple.com/thread.js= pa?threadID=3D2396808&start=3D0&tstart=3D0

Quite = predictably, this has led to a good ol lawsuit. Here's a news
article = and the actual filing:

http://www.bloombe= rg.com/news/2010-07-26/apple-sued-over-claims-ipad-tablet-overheats-in-su= nlight-warm-conditions.html
http://www.docstoc.com/docs/document-preview.aspx?doc_id=3D48234124

The following link, claiming to answering on behalf of iPad = users,
acknowledges the existence of the problem and mocks people for = being
unreasonable for trying to use the iPad in situations where = these
problems can reasonably be expected to occur (their opinion of = what is
"reasonable"):

http://www.theipadguide.com/content/books-have-better-h= eat-tolerance-ipad/7174901

I do not know if any of these = reports are true, if the problems are
endemic or experienced by a few = outliers. What I can tell you is that
whatever the experience at sea = level, the thermal performance will be
worse at 8,000 feet in a IV-P = and worse still at 15,000 ft in a Legacy
-- that is basic = physics.

It is your call how much credence you want to put in = these reports.
Whatever you decide, I would strongly urge you to = thoroughly test
whatever hardware/software you want to use and push = it to the limit in a
realistic environment before you actually put it = in service. The cockpit
is no place for = surprises!

Regards,

Hamid

Chris Zavatson = wrote:
> Thanks for all the replies.
> One more = question.  The apple specs show maximum operating altitude = of
> 10,000 feet.  If there is a good technical reason for = this, it would
> seem rather limiting for our en-route use.  = The operating temperature
> is also kind of pushing the upper = limit when on the ground on hot
> summer days.  The = temperature issue can be somewhat controlled, but
> the altitude = exposure not so much.  Is this a CYA or other generic = limit?
>
>
>       = Environmental requirements
>
>     * = Operating temperature: 32=B0 to 95=B0 F (0=B0 to 35=B0 = C)
>     * Nonoperating temperature: -4=B0 to = 113=B0 F (-20=B0 to 45=B0 C)
>     * Relative = humidity: 5% to 95% noncondensing
>     * = Maximum operating altitude: 10,000 feet (3000 m)
>
>
> = Chris Zavatson
>


--
For archives and unsub http://mail= .lancaironline.net:81/lists/lml/List.html

No virus found in this = message.
Checked by AVG - www.avg.com
Version: 10.0.1153 / = Virus Database: 424/3251 - Release Date: = 11/11/10

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