Russian aviation authorities have grounded the country's fleet of its newest civilian airliner, the Sukhoi Superjet 100.
The ruling by Russian regulator Rosaviatsia comes after metal fatigue was discovered in the tail section of a new Sukhoi plane.
That is a problem usually associated with older airplanes.
Sukhoi said in a statement that it was inspecting the entire fleet "to support the airworthiness of the civilian Sukhoi planes."
It said the defect "of one element of the tail portion" could not cause a crash, but that "airlines must check this model of aircraft."
As a result of the ruling, Russia’s national airline Aeroflot on December 24 grounded 21 Sukhoi Superjet 100 that were scheduled to fly on Russian routes during the holiday season.
The grounding is the latest setback for Sukhoi, which has already had several problems trying to introduce the new civilian passenger plane.
The plane is made in a joint venture with European aerospace suppliers like the French firm Thales and the French engine maker Safran.