Bombardier Aerospace (Chalet CD61) confirmed Ethiopian Airlines today as the customer of an previously-announced order for five Q400 NextGen turboprops, and said that Horizon Air will buy two additional Q400 NextGens.

Based on the Q400 NextGen list price, the Ethiopian order is valued at $160 million. It will bring the number of Q400s operated by Ethiopian Airlines to 13. The carrier serves 64 international destinations.

Seattle-based Horizon Air is the largest operator of the Q400 and Q400 NextGen in North America, with 48 aircraft now in service. The latest “firm purchase agreement” is valued at $60 million, based on list prices.

The 70-to-80-seat Q400 NextGen uses 30 to 40 percent less fuel and produces 30 to 40 percent fewer emissions on routes where it has replaced older jets, according to Bombardier. The aircraft is also 15 decibels quieter than ICAO Chapter 4 noise standards, the company said.

Including the transactions announced Thursday at the Singapore Airshow, Bombardier said it has booked firm orders for 420 Q400 and Q400 NextGen aircraft, with 389 delivered as of year-end 2011.