Bombardier’s Business Aircraft backlog received a much welcomed boost with an announcement on Friday of a firm order for 20 Challenger 350s. Bombardier is not disclosing the customer “for competitive reasons,” but said that firm order is valued at approximately $534 million based on list prices for standard-equipped aircraft.

The order, announced as the second quarter kicked off, comes after Bombardier’s business jet backlog took a $7 billion hit in 2015 with the cancellations of Learjet 85 orders. In addition, the company's business aircraft unit saw gross business jet sales fall from 181 aircraft in 2014 to 119 aircraft last year. Bombardier will detail its first quarter results on April 29, followed by its annual shareholders meeting at its facility in Mirabel, Quebec.

The Challenger 350 order is the latest in a string of fleet orders for the aircraft, which is flown by several large operators, including XOJet, Flexjet, VistaJet and NetJets. The super-midsize aircraft has been among the most delivered business jets, with 68 shipped last year, alone. The aircraft is a follow-on to the original Challenger 300, but has updated Rockwell Collins Pro Line 21 avionics, larger cabin windows and a 3,200-nm range.