Both aircraft manufacturers have good safety records on recently manufactured aircraft and generally, both companies have a reputation of delivering well-engineered and high-quality products. By convention, both companies tend to avoid safety comparisons when selling their aircraft to airlines or comparisons on product quality. Most aircraft dominating the companies' current sales, the Boeing 737-NG and Airbus A320 families and both companies' wide-body offerings, have good safety records. Older model aircraft such as the Boeing 707, Boeing 727, Boeing 737-100/-200, Boeing 747-100/SP/200/300, Airbus A300, and Airbus A310, which were respectively first flown during the 1960s, 1970s, and 1980s, have had higher rates of fatal accidents.[40] According to Airbus' John Leahy, the Boeing 787 Dreamliner battery problems will not cause customers to switch airplane suppliers.[41]