Dash 7

[controller 0]

Hi guys,Recently downloaded the beautiful Dash 7 (d7vcmdla).It is great, particularly the Brymon textures which are promenent where I live.What intrigues me is what are the appendages just outboard of the engines.They look like air refueling housings or missile pods.Anybody have any ideas please ?Thanks a lot,Dave

[kiwiflyer45 123]

I'm sure someone else can give you a more precise answer but I think what you are referring to are the tracks for the Fowler flaps that are housed in a streamlined pod. The pod might also provide some boundary layer control.Fowler flaps are ones that not only move downward to increase lift (and drag) but also extend outwards beyond the trailing edge so they actually increase the wing area and so are more efficient than normal flaps. But extending them out beyond the trailing edge is a tricky business in an aircraft like the DHC-7 as they are very extensive (almost the full span of the wing) and so are going to be subjected to very strong stresses. To make them strong enough to do the job without some form of external strengthening would make them very heavy. So as they extend outwards, it looks to me like there is probably an extra strength track inside that pod to keep the flaps stable. Take a look at them from the outside view as you extend them and I think you will see what I mean.I'm not sure about this but the pod might also reduce the tendency of the of the flow of air under the wing to move toward the wing tips. The flow of air from the top and bottom of the wing trying to move around the wing tip causes a spiral or corkscrew effect called a wing tip vortex and this creates drag. Part of the reason for winglets is to reduce this. Just looking at the fact that the pod runs almost from the leading edge to beyond the trailing edge suggests to me that it might play a role in reducing this by blocking the movement of air under the wing toward the tip.I'm trying to keep this as non technical as I can so don't flame me guys who know a lot more about this than I probably do. Like most pilots, I could explain it much better if I could use my hands to demonstrate it! LOL Hope this helps Dave

[controller 0]

Hello Ian,Thanks for your reply. You are absolutely right about the flap tracks.I went in close and could see their operation.Dave

[kiwiflyer45 123]

Hello Ian,Thanks for your reply. You are absolutely right about the flap tracks.I went in close and could see their operation.Dave

You're welcome Dave. Milton Shupe gave us some great freeware aircraft and the DHC-7 is definitely one of the best. I have the Aerosoft Lukla Mount Everest scenery and one of my most enjoyable (and challenging) flights in FS9 is to fly the Dash-7 in there. It's darn near impossible but if you get everything just right it can be done....Have you checked out Milton's Beech 18? It is an outstanding bit of freewareCheersIan