Transporting Pony Bottles on Airlines

I read with interest the thread regarding use of a pony bottle. I asked the question on that thread about tranporting a pony bottle. I would be interested in hearing from anyone who has flown with a pony bottle out of the US to the Caribbean and Pacific dive sites. My understanding is the bottle must not only be emptied but the valve must be taken out of the bottle - not merely opened. Can anyone confirm their experience regarding this.

Departing the US, nobody has ever checked. Departing MEX, hand search has pulled my pony 3 out of 3 tries. They want the valve seperate from the tank (not just loose) and they may even want to peak inside. I pack (both ways) with valve removed and placed in a baggy and open tank plugged with shipping plug or baggy works OK there also.

awap is correct, the best way is with the valve removed from the bottle.

I have carried 2 AL40s onto planes twice so far and will again in about a week and a half.

I simply remove the valve and drop it in a clean ziplock. Then wrap it in bubble wrap and pack both in the check bags.

I wrap one tank in the wetsuit and stick it in the bottom of the main suitcase and put the second one in a pelican case with other gear. I can generaly keep both check bags under 70 pounds that way...