90.9 percent of ExpressJet Airlines flights were on-time in September 2011 . Labor disputes and maintenance issues contributed to the steep performance drop . The FAA also previously announced in August that it was seeking up to $ 162 million in fines from American for safety violations and had placed American under close scrutiny following its declaration of bankruptcy last November . Overall , Boston airlines ' on-time rates improved over September 2011 , but dropped from September 2011 .
90.9 percent of ExpressJet Airlines flights were on-time in September 2011 . Labor disputes and maintenance issues contributed to the steep performance drop . Overall , Boston airlines ' on-time rates improved over September 2011 , but dropped from September 2011 .