Apparently Delta has changed their policy regarding accepting bicycles as checked luggage. The policy on their web page reads:
"Bicycles Non-motorized touring or racing bicycles with single seats are accepted as checked baggage, bicycles as checked baggage will be $175 (for travel within the United States, U.S. Virgin Islands, and Puerto Rico) and $300 (for travel outside the United States, U.S. Virgin Islands, and Puerto Rico).
Your bike must be packaged in a cardboard or canvas container in one of the following ways:
Handlebars fixed sideways and pedals removed
Handlebars and pedals encased in plastic, Styrofoam, or other similar material
Some Delta Connection® carriers and aircraft may not accept bicycles as checked baggage, and may have different limits. "
I spoke to a customer service representative that said that they do not accept tandems and it is in fact a change in policy.
We've flown on Delta before, with a non coupled tandem in a Bike Pro Tandem Race case (dimensions 34"x72"x10") Last time we did it in Sept 08, they charged us for a bike and an oversized shipment which totalled $350 each way.
Now, they're willing to forgoe $700 in revenue (more than the cost of the ticket) and drive away a platinum medalion customer.
Anybody else that flies Delta might want to email them at Delta.com