Boeing's headache involving the 737 NG jetliner appears to be getting slightly worse.
Boeing said Friday that nearly 5% of the 1,000 737 NGs inspected so far have had cracks in a key wing support, which would raise the number of troubled planes to somewhat fewer than 50.
While the percentage hasn't changed since the problem was first disclosed in September, the number of planes inspected has risen.
Nearly 2,000 737 NGs are subject to the Federal Aviation Administration's inspection order. Before Friday, it has been reported that cracks had been identified in the component known as a pickle fork in 36 planes. They were grounded until they could be repaired.
It didn't help that Qantas, the Australian airline, reportedly found cracks in a 737 NG that had flown fewer flights than some of the others in which the fissures were found, according to news agency AFP.
Boeing emphasized that the cracks have not endangered passengers or crew who traveled in the planes.
The 737 NG was the most recent version of the workhorse single-aisle jetliner before the introduction of the 737 Max, which is currently grounded after two crashes.
The problems in the planes aren't related. The FAA ordered an inspection of 737 NGs that have seen thousands of landing and takeoffs, making them more susceptible to cracks due to extensive use. The Max, by contrast, was grounded while software in the flight control system is rewritten after pilots on both of the doomed flights -- one Lion Air and other Ethiopian Airlines -- were unable to turn off a system that pointed the plane's nose toward the ground. The software is unique to the Max.
"Boeing has provided all 737 NG customers detailed instructions for conducting the inspections and reporting the results," it said in a statement. "The company has held multiple customer engagements to ensure all technical questions are being addressed."
Boeing said it working closely with airlines to develop repair plans, provide parts and technical support.
This article originally appeared on USA TODAY: Boeing 737: More wing cracks found in NG version