How often do commercial aircraft go in for maintenance?

The amount of flight hours makes a large difference in how often aircraft need maintenance. Many airlines and operators create their own plans of maintenance, which depends on the frequency a specific aircraft is in service. Aircraft have set checks at various intervals, often known as flight line maintenance checks and also four different types of higher-level maintenance: A, B, C, and the heaviest (D) checks. Line maintenance is the most frequent and often includes the most basic of inspections.