Partnair Flight 394 dives into the North Sea, killing 55 people. The investigation showed that the tail of the plane vibrated loose in flight due to sub-standard connecting bolts that had been fraudulently sold as aircraft-grade.

Partnair Flight 394 was a chartered flight that crashed on 8 September 1989 off the coast of Denmark, 18 kilometres north of Hirtshals. All fifty five souls on board the aircraft died, making this the deadliest disaster in Danish aviation history. The accident was caused by improper maintenance and use of counterfeit aircraft parts.