European safety specialists are proposing a check on fan blades on CFM International CFM56 engines fitted to Boeing 737s.

The checks follow an incident in which a blade failed on a CFM56-7B powerplant, the result of a fracture in the fan-blade dovetail.

Although the released blade was initially contained by the engine case, says the European Aviation Safety Agency, there was uncontained forward release of debris and the inlet cowl separated.

CFM issued service bulletins in the wake of the event.

EASA says it is proposing a revised airworthiness directive covering a one-time inspection of certain blades, involving an ultrasonic inspection of each one affected, within nine months.

It says any blade on which a discrepancy is detected should be replaced, before release to service or the next flight. EASA says the proposed directive is an interim action and further measures could follow.

While EASA has not specified the incident which led to the proposed directive, a Southwest Airlines Boeing 737-700 suffered an inlet cowl separation as a result of a cracked blade in August 2016.

Source: Cirium Dashboard