Bombardier has received approval to extend maintenance intervals for its NextGen CRJ700/705/900 and Q400 aircraft from Canadian, European and US authorities.
For both aircraft types, line maintenance check intervals have been adjusted from 400h to 600h. Previous schedules required line maintenance checks every 2.2 months based on average daily utilisation of 6h a day. Under the new revisions the intervals are now 3.3 months, resulting in a reduction in direct maintenance costs of the aircraft, Bombardier says.
In order to secure the interval adjustment Bombardier built a database that tracked factors including dispatch reliability and unscheduled removals over a two-year period based on input from customers including Tyrolean Airways.
The methodology used to determine the extended intervals included combining a statistical approach with actual maintenance check findings to predict maintenance requirements. Previously, changes to maintenance intervals could only be requested following five years of in-service data. Now adjustments could be made based on as little as two years of successful results, according to the airframer.