A spate of incidents involving de-icing fluid ingress into the cockpit of Bombardier CRJ700 and CRJ900 aircraft has prompted the US FAA to propose a new airworthiness directive (AD) for the types.

The agency's notice of proposed rulemaking (NPRM), which will affect about 254 units, follows Transport Canada's 8 May AD, which was issued following several incidents of shorting and sparks.

The FAA explains that de-icing fluid can enter between the windshields and side windows, leading to possible damage to the electrical components and wires as it comes into contact with cockpit floodlight electrical connections.

Additionally, de-icing fluid in contact with cockpit floodlight electrical connections can result in possible arcing and fire.

The actions to address the unsafe condition include performing a leak test, applying sealant between the windshields and side windows, and doing related investigative and corrective actions, including a follow-up leak test after sealant is applied.

The FAA estimates that it will take about four work-hours per product to comply with the basic requirements of its proposed AD. Based on an average labour rate of $80 per hour, the agency estimates the cost of the proposed AD on US operators to be $81,280, or $320 per product.

Operators have until 25 September to comment on the NPRM.

Source: Air Transport Intelligence news