A new deal between Pinnacle Airlines and its pilots, if ratified, will provide Delta Air Lines with a solution to reducing the number of 50-seat jets operated by its regional airline partners to 125 or less by the end of 2015. What is not publicly disclosed, however, is how Delta plans to dispose of all of the 181 Bombardier CRJ200 aircraft now scheduled to be retired from the mainline carrier’s operational fleet.

Delta currently has 10 CRJ200s and 34 CRJ100s from its defunct subsidiary Comair in storage, the vast majority of which are parked in the desert. The CRJ200s all were manufactured in 1999 and 2000 and the 34 CRJ100s were built between 1994 and 1999.

Pinnacle on Dec. 18 reached a tentative agreement with its Air Line Pilots Association (ALPA) chapter on pay, retirement, and other cost concessions as part of the airline’s Chapter 11 reorganization.

It is operating under debtor-in-possession (DIP) financing from Delta, but the regional carrier already has drawn all of that loan. If the ALPA Master Executive Council at Pinnacle sends the deal for a vote, that balloting will need to be completed by mid-January to comply with the most recently revised DIP deal-imposed deadline.

Pinnacle says a separate agreement between itself, its pilots and Delta will provide for “long-term career opportunities” for current Pinnacle pilots and the addition of 40 CRJ900s to its fleet, with deliveries beginning in late 2013 and concluding by the end of 2014.

Those are the 40 76-seat CRJ900s that Delta agreed this month to acquire, although Delta still has not decided whether they will go on its own balance sheet or that of its regional partner.

The agreement brings Pinnacle’s long-term fleet plan to 81 CRJ900s, but the carrier also agreed to remove the 140 CRJ200s it operates for Delta over the next two to three years. That could slash Pinnacle’s pilot workforce by more than two-thirds.

Delta is confirming that it will be responsible for the 140 CRJ200s operated by Pinnacle. But it will not say what it expects to do with them. All are owned by Wells Fargo under lease to Delta.

About a third of them are accounted for. Under Delta’s recent deal with Bombardier, the airline is acquiring 40 new 76-seat CRJ900 aircraft and sending 60 50-seat CRJ200 aircraft back to the aircraft manufacturer. Those 60 will be from among the ones returned by Pinnacle, Delta tells Aviation Week.

A Bombardier spokeswoman earlier this month said the manufacturer is confident in its ability to find a home for these returned aircraft in places such as Africa and Russia, although parting some of them out also will be an option.

All of the Pinnacle CRJ200 aircraft were manufactured between 2000 and 2005.

Separately, under an agreement that Delta reached with SkyWest Inc. in August, that regional partner will operate an additional five CRJ700 aircraft and 29 CRJ900 aircraft for Delta in exchange for the early termination of 66 CRJ200s it operates under its existing Delta Connection agreements.

SkyWest said it would start removing the first of those 66 aircraft in August and the last by December 2015. Of those, 41 are Delta-financed aircraft that SkyWest will return to Delta, while the remaining 24 are SkyWest financed aircraft that will remain the regional carrier’s responsibility.