Bombardier is hoping for recertification of the Learjet 45's horizontal-stabiliser actuator assembly after submitting a data package to the US Federal Aviation Administration late last week. Around 200 of the light business jets remain grounded after the FAA issued an emergency airworthiness directive (AD) on 13 August requiring replacement of the screwjack actuator, which it says was not manufactured in accordance with the type design data.
Rather than redesign the actuator, Bombardier has launched an effort to requalify the component, generating a complete certification data package including updated drawings and documentation.
If the recertification effort succeeds, supplier MPC Products will produce new actuators to the same design, but with a different part number, allowing operators to comply with the AD. The FAA does not claim to have proven the parts are defective, rather that documentary proof that quality control processes during manufacture were followed had not been provided.
The AD states: "During our investigation of this problem we determined that the configuration and quality controls over the production of these parts were so deficient that we do not have confidence that the aircraft can be operated safely for any period of time."
The FAA is still smarting over criticism of its oversight of Alaska Airlines after the January 2000 loss of a Boeing MD-80, which crashed after the screwjack in its stabiliser actuator fractured, although that was down to maintenance laxity rather than a manufacturing error.
Bombardier was last week unable to estimate when Learjet 45s would return to flight, but European operator Gold Air hopes its aircraft will be airborne by the end of this week.
Source: Flight International
