Plans at Delta Air Lines to reduce the number of 50-seater regional jets (RJs) that it contracts with regional airlines has raised fears that it might shut down its wholly-owned subsidiary Comair.

The Atlanta-based carrier is nearing the final stages of its previously announced reduction in the regional carrier's 50-seat Bombardier CRJ100 and CRJ200 fleet to just 16 aircraft this August from 68 at the end of September 2010, when the drawdown was announced. Comair also operates 15 70-seat CRJ700 and 13 76-seat CRJ900 aircraft.

Delta says that Comair will have 16 CRJ200s, 15 CRJ700s and 13 CRJ900s in its fleet at the end of the year when the reductions are scheduled to be complete.

That fleet total for the end-of-the-year is now in question as a result of Delta's tentative labour agreement with its pilots, says multiple sources at Comair.

Delta wants to remove 218 50-seat RJs from its regional fleet for a total of 125 and add 70 76-seat jets by 2015 that would result in a reduction of the Delta Connection fleet to 450 aircraft, plus a few exceptions, from 608 at the end of March. It would also acquire 88 117-seat Boeing 717-200s from Southwest Airlines-subsidiary AirTran Airways under the same timeline, as an incentive to its pilots.

The plan is contingent on its Air Line Pilots Association (ALPA)-represented pilots approving the agreement. Voting began on 15 June and is scheduled to end on 29 June.

Delta would swap out two 50-seat jets for every one 76-seat jet at its contract carriers under the plan, according to a negotiators' notepad on the agreement from ALPA last month.

These numbers have raised eyebrows. By a simple calculation, ALPA's 2:1 ratio only works if either the CRJ900s or the CRJ700s operated by Comair are included.

As the numbers stand currently, the swap between 50-seaters and 76-seaters would be closer to 3:1, based on the 218 and 70 numbers. However, if Comair's 28 CRJ700 and CRJ900s are added to the number of aircraft going to contract carriers, a ratio much closer to 2:1 is obtained.

"If [Comair's] 50-seaters are parked and either the CRJ900s or CRJ700s are used in two-for-one deal with other contract carriers, Comair could be unviable as a carrier," says a source at the regional airline. They note that Delta may need to offer incentives to contract carriers to reduce their 50-seater fleets.

The majority of the 50-seater fleet is contracted through 2017 or later.

Delta leased 12 CRJ700s that are owned by Comair to Trans States Airlines-owned GoJet through 2020 earlier this year. The carrier is known for having some of the lowest pilot costs per block hour among regional airlines.

ALPA would not comment on how it reached the two-for-one number.

The airline did not comment on its plans for Comair but says that it is too early to discuss fleet plans until after its pilots vote on the tentative agreement.

Source: Air Transport Intelligence news