A Nordwind Airbus A321-200, registration VP-BGH performing flight N4-1606 from Heraklion (Greece) to Moscow Sheremetyevo (Russia), was climbing through FL250 out of Heraklion when the crew initiated an emergency descent to FL070 due to problem with the cabin pressure, the passenger oxygen masks were not released. The aircraft returned to Heraklion for a safe landing about 40 minutes after departure.
A passenger reported children on board felt pressure on their ears while the aircraft was rapidly descending, the oxygen masks did not deploy. The passengers were rebooked onto other flights.
The occurrence aircraft is still on the ground in Heraklion about 14 hours after landing back.
On May 11th 2017 the Greek AAIASB reported the aircraft had been dispatched under minimum equipment list requirements with the #1 bleed air system inoperative. While climbing through FL180 the #2 bleed air system failed prompting the crew to declare Mayday and descend the aircraft to FL100. The aircraft returned to Heraklion. The occurrence was rated a serious incident and is being investigated.