EASA today issued an emergency airworthiness directive (AD) calling on operators of ATR 42 and ATR 72 turboprops to inspect or replace within 10 days cockpit forward side windows that have accumulated more than 2,000 flight cycles.
The mandate was issued after the left-hand forward side glass window on an ATR 72-212 "blew out" while ground crews were performing a pressures test, according to EASA.
An investigation of incident aircraft revealed "some anomalies" on both the external and internal sides of the window that were considered to be precursors of the failure.
Operators are to inspect the windows based on service bulletin issued by window maker, PPG Aerospace.
"An in-flight loss of a forward side window could have catastrophic consequences for the aeroplane and/or cause injuries to people on the ground," the EASA writes in the AD, adding, "The loss of the forward side window while the aeroplane is on the ground with a positive differential cabin pressure could also cause injuries to people inside or around the aeroplane."