UNDATED-AP- Some of the nation’s busiest airports saw hourslong security lines this weekend, as the partial government shutdown begins to hit air travel. Most checkpoints use federal TSA screeners, who must work without pay during shutdowns. San Francisco International Airport, however, uses a pri vate screening contractor under TSA oversight, which keeps lines moving. Some experts say the model deserves a closer look as a way to protect airport security operations during lapses in funding. But the TSA union warns privatization could cut pay and protections for workers and introduce security risks. Travel industry groups are pushing another solution. They say Congress should pass legislation to keep aviation workers paid during shutdowns. ...read more read less