Boeing on Tuesday said first-quarter deliveries of its narrow-body 737 MAX jets could face delays due to wiring flaws, the latest hiccup for the troubled planemaker as CEO Kelly Ortberg looks to improve production quality and the company’s reputation. 

Boeing said on Tuesday it has secured a firm order from aircraft leasing company Aviation Capital Group (ACG) for 50 units of its 737 MAX jets, the manufacturer’s mainstay aircraft for the global commercial aviation market.

FlyDubai said Wednesday it ordered 75 Boeing 737 MAX aircraft in a deal worth $13 billion.

Vietnamese budget carrier VietJet is set to take delivery of its first Boeing 737 MAX this Sunday, more than nine years after placing its initial order, according to company and government documents.

The US Justice Department said Friday it reached a preliminary agreement with Boeing to settle a long-running criminal probe into deadly 737 MAX crashes, drawing condemnation from some crash victim families.

Boeing is preparing to seek approval from the Federal Aviation Administration (FAA) to increase production of its top-selling 737 Max jets to 42 units per month later this year, CEO Kelly Ortberg announced on Wednesday.

Boeing has restarted production of its best-selling 737 MAX jetliner, marking a crucial step in the company’s recovery after a seven-week strike by 33,000 factory workers.

Boeing (BA.N), opens new tab said on Tuesday it plans to make design changes to prevent a future mid-air cabin panel blowout, opens new tab like the one in an Alaska Airlines (ALK.N), opens new tab 737 MAX 9 flight in January that spun the planemaker into its second major crisis in recent years, News.az reports citing Reuters .