Boeing delivered 43 airplanes in July, a second straight relatively solid month for the jet maker as it works to ramp up production amid supply-chain glitches and in the wake of January’s Alaska Airlines door-plug blowout. That total included 32 737 jets, three fewer than Boeing delivered in June but higher than earlier in the year when it was delivering between 15 and 25 narrowbodies per month. Deliveries included six 787s, four 767s and one 777 freighter. Boeing’s backlog is now 5,477, down from 5,506 at the end of June.