How can I turn on Airdrop from everyone for an hour instead of just 10 minutes? Ten minutes is simply not long enough in a group meeting where files are being shared between members.

The ten minute limit was intentionally introduced by Apple to ensure that AirDrop was not unintentionally left “open” to receiving from any source - in part in response to widespread complaints, from users, concerning unexpected/unwanted receiving of (potentially pornographic or otherwise offensive) images in public locations.

Prior to implementing this change, users would often change their AirDrop settings to "Everyone" - and then forget to subsequently re-secure the iPad from unwanted material when an intended transfer had been completed.

Setting aside the implications of users receiving unwanted files/images through unintentionally leaving AirDrop open to “Everyone”, this change reduces the available attack surface for malware or other exploit.

Ratleader wrote:

I was afraid it would be like that, and it does sound “safer.” Just think how safe the new Apple Car will be, since it will only run for ten minutes before it brakes to a stop, and the engine has to be started again. And the Apple Airplane, what a wonder of safety that’ll be!

That analogy is false on at least two levels.

Apple Cancels Electric Car Project

You can’t. The setting was restricted for security reasons.