Alaska Airlines just did the worst thing an airline loyalty program could do — Mileage Plan made a huge award chart devaluation with no advance notice whatsoever.

My favorite Alaska Mileage Plan partner airline — or at least the one I’ve redeemed the most miles for — is Emirates. Since Mileage Plan award redemptions on Emirates became possible in early 2013, Alaska has charged the following number of miles for one-way first class redemptions on Emirates:

— North America to Middle East/India — 90,000 miles
— North America to Africa — 100,000 miles
— North America to Asia — 100,000 miles
— North America to Europe — 100,000 miles

Alaska Mileage Plan added Hainan Airlines as an award redemption partner yesterday, but that’s not the only change they made to Mileage Plan redemption rates. Alaska also greatly increased the cost of Emirates first class redemptions, without any notice. And the changes are brutal.