Find My Phone, and Airplane mode

Yes. Airplane mode turns off everything related to connectivity.

For "Find my iPhone" to work the iPad must be connected to the internet in some way. Either over Wifi or Cellular connection. Airplane mode disables these 2 options so Find my iPad will not work.

Fortunately, the new in flight regulations will now allow you to keep the iPad and other mobile devices turned on during flight.

Turned on, yes, but they require it be in Airplane mode, which is still a problem for the original poster looking for a way to locate a device left on a plane. I've also learned this the hard way.

No. The new rules would allow passengers to use the device fully. Connected to Wif or cell (however, no cell towers at 30000 feet).

http://www.fcc.gov/guides/wireless-devices-airplanes

FCC wrote:

The FCC has proposed rules that, if adopted, would give airline carriers the ability to allow passengers to use their mobile wireless devices, such as cellphones, to communicate with cellular frequency equipment while flying above 10,000 feet. Ultimately, if the FCC adopts new rules, it will be the airlines' decision, in consultation with their customers whether to permit the use of data, text and/or voice services while airborne.

The current rules already allow a passenger to have a mobile device turned on but in flight mode after takeoff.. The new rules would expand on that. To include connectivity.

Here's to hoping it's approved. Regardless of connection at 30,000 I like the idea that you can leave it all on and then when back on the ground an Apple device is immediately searchable through Find My iPhone. I'm tempted to leave it on anyways, despite current regulations, based on my unfortunate experience recently leaving my iPad in a seatback pocket and not being able to locate it due to Airplane mode.

Great information from all of you, I must humbly admit I too recently lost my iPhone 4S IOS 7 on a flight from Cairo to Sharm El Sheikh, and if you think domestic airlines in the US are difficult to get help from to locate a phone, try Egypt Air. Of course, it was in airplane mode and I didn't realize it was lost until I arrived at the resort. Taxis in Egypt are independent - not with companies - so the chance of finding the driver are slim to none! At least my AT&T domestic plan allowed me to obtain a replacement via insurance. (Albeit a forced upgrade to iPhone 5C for $120)

Best regards to you all!

I agree, there should definitely be a warning or prompt when turning into airoplane mode to say that find my phone will not work