Oh, silly me - i.e. if your iPad is on 'Airplane Mode', the BT (and Wi-Fi) radios are off, so BT headphones are of no use 'in the air' although iPads can still be used in that mode (don't fly as much as I use to and not sure if all airlines, especially from different countries, have the same rules?).
BUT, as to your question, any type of headphones that use a 3.5 mm mini-stereo plug will work, depending on the style you like (e.g. ear buds vs. over the ear), their overall size, and the price you want to pay; although more costly, you might also want to explore 'noise cancellation' headphones? Dave