A new airworthiness directive issued by Transport Canada requires all Airbus A220 operators in Canada to modify the jet, after an in-service engine shutdown during taxiing was reported to have been caused by rain water.

On September 4, 2020, Transport Canada issued an order to modify drain tubing of A220s following an incident in which rainwater dripped into the avionics bay, tripped a circuit breaker during taxi and caused the engine to shut down.

Transport Canada, the Canadian aviation regulator, explained that the rain water had entered the jet through the main cabin entry door while it was open, causing the drains to overflow and dripping on the forward avionics bay below. The exact date, the company involved or other details of the incident have not been made public. 

According to the regulator, during the investigation it was found that the ingress of water into the forward avionics bay caused a short circuit and a circuit breaker led to the engine shutdown.

“Water ingress into the forward avionics bay could short circuit the equipment in the area and lead to a loss of air data sources resulting in a reduction in functional capabilities, and an increase in crew workload“, in the order stated the regulator.

The Canadian regulator specified what modifications on the A220s must be done in order to avoid similar cases in the future. The airworthiness directives require operators to install blanking plates on certain drains and block off the associated drain tubing to prevent any future water ingress from the forward galley drains into the forward avionics.

Following the directive, modifications of A220s have to be completed within 12 months from September 18, 2020. Otherwise, the carriers will be banned from operating A220s in Canada.

It is not the first directive that concerns safety issues of Airbus A220. Earlier on April 1, 2020, the Federal Aviation Administration issued its own airworthiness directive on A220 following a series of engine failure incidents involving the aircraft in Europe.

In October 2019, a Swiss International Air Lines A220 jet en-route to Geneva from London had to divert to Paris due to an engine failure. During the inspection of the engine casing there were found fragments of torn loose from the engine.

A bit later, in July 2019, another Switzerland flag carrier’s A220 aircraft was flying over Paris when the turbine disintegrating caused an engine shutdown.

Another incident concerning engine failure happened in February 2020, when an airBaltic Airbus A220 en-route from Latvia to Spain diverted to France after encountering an engine problem.

Originally, the A220 was designed by Canadian manufacturer Bombardier Aerospace and initially marketed as the Bombardier CSeries. But in 2018, the airliner program was sold to Airbus Canada for further development. The next year, in January 2020, the newest addition of the Airbus family, the A220 jet, received Transport Canada’s approval for operations in Canadian airspace.