I'm no expert, and can't even considered to be "knowledgeable", but I believe the iPad contains a hard drive (???). If so, hard drive heads are generally supported by air bearings and in that case there is a real altitude limit that shouldn't be exceeded. But maybe the 10,000 ft rating is conservative and it could be run higher (??). But a hard drive failure because of altitude might be permanent (??). Sorry, lots of questions and no real answers. The "23k" mentioned below
doesn't count.
Gary
had it at 23k pressurized to 6,000 field elevation works there (evo)