MIAMI — Horizon Air Industries, the regional partner for Alaska Airlines, announced a firm orderfor one Bombardier Q400 NextGen turboprop at the Farnborough Airshow on Tuesday in an order worth $32.6 million at current list prices.

Horizon Air retains options to purchase seven purchase options for the Q400 NextGen, and the order will grow its fleet to 52 aircraft, cementing Horizon Air’s standing as the largest operator of the Q400 in the world. Bombardier and Horizon Air also inked a deal for the manufacturer to provide heavy maintenance tasks for Horizon Air’s Q400 fleet for five years at Bombardier’s service center in Tucson, Arizona.

With the purchase, the Q400 has reached 499 firm orders with more than 458 aircraft delivered to date. Horizon Air and United Express (via Republic Airlines) are the type’s only two operators in the United States. Republic has 31 two-class Q400s in its fleet with one additional aircraft on order.

Alaska Airlines recently introduced the Q400 onto flights within the state of Alaska, where the Q400’s strong runway performance and lower passenger capacity are useful tools. The Q400 is the dominant regional aircraft for Alaska Airlines, though the carrier also has five Bombardier CRJ-700s contracted from regional partner SkyWest Airlines.