Bombardier Learjet 45s returned to flight last week, after the US Federal Aviation Administration approved a redesigned horizontal stabiliser actuator assembly.

Supplier MPC Products is upgrading actuators returned by operators of grounded Learjet 45s with a new screwjack that uses a proven design and materials. The manufacturer expects all 231 aircraft grounded by the FAA's 13 August airworthiness directive (AD) to be flying within two weeks.

The FAA originally issued an AD in March requiring fleet-wide replacement of the actuator assembly, after a fracture led to "severe vibration followed by a rapid nose-down pitch change".

Source: Flight International