The president and CEO of JetBlue Airways is “disappointed” with the carrier’s fleet of Embraer 190s and says the airline continues to struggle with maintenance costs on the 100-seat E-Jets.

“We should never have been the worldwide launch customer of a new airplane,” David Barger said in an April 21 address to the Harvard Business School’s Aerospace & Aviation Club in Boston, adding, “We weren’t big enough.”

Barger also expressed unhappiness with the Brazilian aircraft’s General Electric CF34 engines. “We’re not pleased with what we’re seeing on the Embraer [with] the GE motor,” he said.

JetBlue operates 54 100-seat Embraer 190s, supplementing 126 150-seat Airbus A320s that are used on longer-haul routes, according to the Aviation Week Intelligence Network fleets database. Barger, who stretched out deliveries of the E-190s after becoming CEO in 2007, stopped short of saying he regretted ordering the aircraft. He notes that the 190s are optimally sized for JetBlue’s expansion in Boston and other key growth markets.

Barger says the airline has significantly driven down maintenance costs, but not enough. “We’re seeing our later 40 [190s] performing better than our first 20,” he said, indicating that he would have more detailed comments on the maintenance challenges during JetBlue’s earnings call on April 25.

JetBlue ordered 100 Embraer 190s in 2003 and took its first delivery in 2005. The airline struggled with early maintenance issues and delivery delays, hiccups that have been acknowledged by Embraer. “Back in 2006-07 we were still struggling on the [E-Jet] production ramp-up, dispatch reliability of the aircraft, and we were late on deliveries,” Embraer CEO Frederico Fleury Curado told Aviation Week in 2010. “JetBlue was the most visible, but other customers also had problems.”

The Embraer 190/195 E-Jet family went on to win wide market acceptance. In a surprise move, in January the airframer selected Pratt & Whitney’s geared turbofan engine for a second generation of E-Jets expected to enter service in 2018. The decision was a major blow to E-Jet engine incumbent General Electric.