Porrohman,
It is normal for a DH8D to have the propellers spinning in a crosswind after the engines have been shut down. This is a major issue when boarding or disembarking passengers, as many have a tendency to wander around in the area of the propeller.
However, judging from the evacuation video provided by Flight Mode, and seeing the direction the props are spinning, I am under the distinct impression that it is the downwind leg that collapsed and in fact that was first touched down, not the upwind one.
In the last second of LookingForAJobs video, the collapsed gear is shown. It is remarkable that the rear gear doors appear open; they only open during extension and retraction and, in case of extension, close some seconds after the leg has been locked down. This door should definitely be closed in this flight phase. It is not linked to the landing gear struts in any way (unlike the forward doors that stay open when the gear is extended) but has its own hydraulic cylinder and its movement is sequenced by the PSEU (Proximity Switch Electronic Unit). The only situation I can imagine that leaves the gear door open after an extension is after the execution of the "Alternate Gear Extension" procedure. But this would have left also the door on the L/H MLG open, which is shown closed on several pictures. So why this door is open in this situation is not really clear to me.
The gear in the same video looks to be in an intermediate position between uplock and downlock, i. e. failed in the direction of normal retraction. The correct function of the downlock will therefore likely be of relevance in the investigation.
Last edited by Tu.114; 23rd Feb 2017 at 18:20.