Turkish Airlines said it intends to purchase 40 of Boeing’s 787-9 Dreamliners, a long-awaited deal that signals the carrier’s rebound following a terrorist attack on its Istanbul hub last year.

When finalised, the order would be valued at almost $11 billion before the customary discounts for large aircraft purchases. The pact, unveiled during a brief signing ceremony in New York late Thursday, came after years of market studies and negotiations for wide-body planes as the airline plotted its expansion.

Boeing’s carbon-composite Dreamliners will help upgrade Turkish’s fleet of long-range aircraft as it competes with other Middle Eastern airlines amid slowing growth in the region. The carrier’s expansion would hasten President Recep Tayyip Erdogan’s goal of making Istanbul one of the world’s premier air travel hubs. The airline already has 75 Boeing 737 Max jets on order, according to the planemaker’s website.

According to ABC News, Boeing has issued a software update that changes the function of MCAS in two significant ways. First, the aircraft manufacturer announced that if the two AOA sensors on the plane offer “widely different readings”, MCAS will deem it a faulty reading and will not activate a pitch-down manoeuvre.

Secondly, the firm added that if a scenario occurs in which the MCAS system is triggered, it will now perform the automated pitch-down only once, allowing the pilots to take control of the plane and negating the possibility of a faulty AOA reading causing the plane to continuously fight against pilot inputs.