Q: Bluetooth on iPad Air 2 not detecting any devices at all

What are you trying to connect to? You do not indicate that at all, just that you cannot detect any devices. The iPad supports a number of profiles for Bluetooth, but may not support what you are trying to do. Please provide a little more info.

You are not going to connect to the iPhone 5s, except to use tethering. That is not supported. As far as the wireless headphones are concerned, please look at the documentation that came with the headphones and put them into discovery/pairing mode and then attempt to connect. If the devices are not showing up, then they are not in discovery/pairing mode.

I Have same problem. I am trying to connect a hands free to iPad Air 2. The same hands free connects to my iPhone 5s. The bluetooth when turned on detects no device. Your help will b appreciated.

read the headsets manual how you put it in pairing / discovery mode this is required for a headset to connect with a device it has not connected to before

Its not even detecting my iphone which it previou used to detect.

read what I write about putting your headset into pairing  / discovery mode

and about 2 ios devices and bluetooth then they don't really have much to say to each other

iOS: Supported Bluetooth profiles - Apple Support