The cultural difference with regards to retro is not as big as you think. Both premerger pilot groups negotiated retro pay in the past. In 1998 the NWA pilots negotiated 3.5% retro for the two years between the amendable date and date of signing. In may of 2001 the Delta pilots negotiated 3.8% retro (with some exceptions such as Express) for the one year between the amendable date and date of signing.

Recent negotiations have yielded signing bonuses, which as you correctly state is more than zero. The FDX pilot contract became amendable in 2010, they signed a 2%/year, two year extension. They eventually got a 6 year contract ratified 5-years after the amendable date with a signing bonus of $125 million dollars, or roughly $30,000/pilot for the entire 5 years past the amendable date, or put another way $6,000/year retro. Total cumulative gains achieved over the 11 years this contract contains is 33.9%.

SWAPA achieved a TA in 2015, three years after the amendable date, with retro of approximately $15,000/pilot for the three year wait, $5,000/year retro. That TA was rejected and they are now four years past the amendable date.

We're just 5 months past our amendable date, full and meaningful retro is still possible, but the longer this drags out the less likely full retro becomes, if by full retro we are talking about 22% on the amendable date, which is our current table position. What's full retro 3 years from now, is it 22% +7% + 7% + 1% DC/year?