SAN FRANCISCO, July 29 (Xinhua) -- The Boeing Company on Tuesday reported a second-quarter revenue of 22.75 billion U.S. dollars, a 35 percent leap year over year, with a narrowed quarterly net loss of 0.61 billion dollars.

The company recorded a loss of 0.92 dollars per share. Its operating cash flow was 0.23 billion dollars for the quarter.

The results primarily reflect improved operational performance and commercial delivery volume, according to Boeing, and they come after a strike that brought most production to a standstill last year.

Commercial Airplanes' second-quarter revenue of 10.87 billion dollars and operating margin of minus 5.1 percent primarily reflect higher deliveries, the company said. They delivered 150 airplanes during the period, a 63 percent increase compared with 92 airplanes a year ago.

Boeing is facing a certification challenge due to problems with the 737 MAX models' engine de-icing systems, which are more complicated than expected, Boeing President and CEO Kelly Ortberg told CNBC.

"As we look to the second half of the year, we remain focused on restoring trust and making continued progress in our recovery while operating in a dynamic global environment," said Ortberg in a press release.

Boeing's Defense, Space & Security revenue in the second quarter was 6.62 billion dollars. The quarterly operating margin of 1.7 percent reflects stabilizing operational performance, the company said.

Its Global Services second quarter revenue was 5.3 billion dollars with an operating margin of 19.9 percent.

In the release, Ortberg said that "fundamental changes to strengthen safety and quality are producing improved results as we stabilize our operations and deliver higher quality airplanes, products and services to our customers."