August 2016, Swiss reported "much higher" reliability than other all-new airliners, citing Airbus's A320, A380 and Boeing's 787. After four months of service with Swiss, this goal seemed to have been met based on only three aircraft and 1,500 hours flown; "nuisance messages" from the integrated avionics suite and engine start-up delays had been the main griefs. Dispatch reliability rates of 99.0% were met in April 2017. A year after introduction, in July 2017, launch operators had fewer issues than expected for an all-new aircraft program. At this time point, airBaltic had already a 99.3–99.4% dispatch reliability, similar to the established Q400 but less than the relatively ubiquitous Boeing 737 Classic's 99.8%. The dispatch reliability improved further to 99.85% in October 2017. Engine reliability Since the PW1500G mount generates less strain on the turbine rotor assembly than the A320neo's PW1100G, it does not suffer from start-up and bearing problems but still from premature combustor degradation. An updated combustor liner with a 6,000–8,000 hour limit has been developed and a third generation for 2018 will raise it to 20,000 hours in benign environments. After three inflight engine failures in 2019, Transport Canada issued an emergency airworthiness directive (EAD) limiting the power to 94% of N1 (Low Pressure Spool rotational speed) above , disengaging the autothrottle for the climb over this altitude before engaging it again in cruise. Maintenance The A check is scheduled after 850 flight hours: the check originally took 5 hours and has since been reduced to less than 3 hours, within an 8-hour shift. The C check is scheduled after 8,500 hours – translating to about 3.5 years of operation. Based on experience since product launch, A checks intervals could increase to 1,000 hours and C checks to 10,000 hours toward the end of 2019. Variants There are two main variants: the shorter A220-100 including the ACJ TwoTwenty business jet version, and the 3.7 metres longer A220-300. Their commonality over 99% allows a common spare part inventory, reducing investment and maintenance costs. A220-100 The A220-100 is the shortest variant of the A220, seating typically between 100 and 130 passengers. Originally marketed by Bombardier as the CS100, it competes with the Embraer E190 and E195. Marketing designation of the BD-500-1A10 for aircraft from serial number 50011. A220-300 The A220-300 is the larger of the two A220, being 3.7 m (12.1 ft) longer than the -100, and carrying between 120