LJ,
I believe that is correct. Yes, a current ALPA member in good standing when the LTD took effect. I believe that there are 2 ways in which you can eliminate your dues obligations while you are out on LTD, providing you're current, prior to your LTD. The first is to resign from ALPA. The second way is to suspend your membership. You will still be an ALPA member, and you'll not have to pay dues, but you can't vote as a paying member can, nor (I believe) can you increase or add ALPA sponsored insurances. Once you return to work, you can reactivate your membership.
JJ