Widerøe had an incident that sounds similar to me, back in 2006. Found a preliminary report at the Norwegian NTSB, it only contains a short summary (roughly translated with Google translate):
"Serious aircraft incident with Wideroe LN-WIE. Early during the approach to Sorkjosen the plane came into strong turbulence. The right propeller experienced uncontrolled overspeed so that the engine had to be shut down. The aircraft banked heavy to the right and lost approx. 1000 ft. The approach was aborted and the aircraft returned to Tromsø. Major damage to the right engine / propeller. Available information indicates that when the aircraft was slowed down because of turbulence, the power levers accidentally came into the area for reversing the propellers. It is considered that the power levers should be modified. In the meantime, the company has implemented measures to prevent recurrence. Immediate recommendation sent to the Canadian Aviation Authorities February 2007. It is advised that the power levers are improved and that all operators are cautioned against the danger of inadvertent reversal in the air. The case is still under investigation."
The report in Norwegian can be found here:
06/120 | sht
Widerøe's internal investigation report (in Norwegian):
Widerøe: Widerøes granskningskommisjon: Ingen feil på Wid...
Norwegian newspapers reported on the incident, and my summary is as follows:
The internal investigation carried out by Widerøe, says that the autopilot was turned off because of strong turbulence. The plane was at 9000 feet. The passengers disputes this, saying that before the landing there was calm, no turbulence. There was a sudden "revving" of the engine. The plane lost 300 meters, it banked 60 degrees to the right, and 17 degrees nose down (obviously this information was provided by Widerøe, who was in contact with the passengers on the results of their internal investigation). The RPMs of the propellers was so high that the sound barrier was broken, and the bang could be heard in several places in the North of Troms (the county). There was smoke in the cabin. When the plane landed there was oil spill and visible damage to the engine:
NRK.no - Troms
Scary incident, no doubt. Is this what happende with the Airlines PNG Dash 8? Only with both engines?