So if Flybe, as the largest Q400 user, is replacing their TP by jets, why should SN take over those airplanes from Flybe and downgrade its capacity?
SN needs to do now what Flybe started doing 10 years ago.
That is to re-build the regional part of its short-haul strategy from the ground up and become profitable, all while adding long-haul aircraft and increasing demand for feeding.
Once SN's TP fleet achieves 90% load factors and the long-haul fleet grows to about 15 aircraft, then we can talk about replacing the TP's by larger jets, through merged frequencies.
As much as Flybe has been successful with its TP strategy in the past, I doubt that their future strategy would enhance their profitability.
Operating a large fleet of turboprops is ideal for a network carrier's regional fleet operating under a mainline and long-haul fleet, but it's a huge handicap for an airline like Flybe for whom it's the only source of revenue.
So Flybe's strategy is to go larger and to enhance the revenues and profitability while exposing itself to more risk. They did that successfully in a first stage by replacing Q400's by E195's on the routes that they were able to grow successfully thanks to the Q400.
I however doubt that their E170 strategy on mainland Europe would take them anywhere. At current fuel prices, the E170 is not sustainable to operate, especially at typically lower load factors on regional routes.
If done right, there would be no capacity downgrade, quite to the opposite.
SN's current short and mid-haul fleet has a low utilization rate. Throughout the day you see many aircraft parked on the tarmac or in the hangar.
This means that if 26 RJ's are replaced on a 1:1 basis with Q400's, the Q400's can achieve a higher utilization and operate more frequencies. This would lead to additional, better spread capacity.
As I've said repeatedly, the more you spread your capacity (more schedule options and regional destinations), the more revenue and profit potential you have.
By the way: introducing airplanes means a cost: leasing or buying. SN is not in the financial position to say " get me those birds, here you have a cheque"
If negotiated well with BBD/ATR and financial institutions, SN may achieve to get new TP's at around half the price of A320 leases. It's still a lot more than what they pay for the RJ's.
At current fuel prices, the money they save on fuel easily covers the higher lease and additionally save no less than several millions per aircraft per year.
Roughly, at 250 hours per month,
fuel+lease RJ85 = 2 x fuel+lease Q400NG or
fuel+lease Q400NG = 50% x fuel+lease RJ85
Maintenance on new aircraft would in first instance cost next to nothing because of warranty (typically first 3 years) and there would be a permanent difference because of lower maintenance and replacement cost of turboprop engines. Turboprop engines are easier and cheaper to maintain.
Lower cruise speeds and lower pressure delta due to the lower cruise altitudes puts less strain on fuselage and pressurisation related systems, requiring less inspections and repairs.
This will save SN millions on maintenance bills and enable it to shift more maintenance resources to work on additional A330's.