Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as
:During flight-testing of a wing anti-ice piccolo tube containing a deliberate small breach, it was determined that the wing leading edge thermal switches were not detecting the consequent bleed leak at the design threshold. As a result, new Airworthiness Limitation tasks, consisting of a functional test of the wing leading edge thermal switches and an inspection of the wing anti-ice duct piccolo tubes, have been introduced in order to limit exposure to dormant failure of the switches in the event of piccolo tube failure, which could potentially compromise the structural integrity of the wing leading edge and the effectiveness of the wing anti-ice system.
The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.