Aviation US airlines sending teams to review Boeing 737 MAX upgrade this weekend Updated : March 23, 2019 11:13 AM IST The meetings are a sign that Boeing's planned software patch is nearing completion, though it will still need regulatory approval. Southwest Airlines Co, American Airlines and United Airlines operate 34, 24 and 14 MAX jets respectively. Subscribe to Moneycontrol PRO at just Rs.33/- per month for the first year. Use code SUPERPRO. Limited period offer. Available on Web and Android.