PAD Saab 340

[aeromed202]

I have been talking with the folks at PAD about this aircraft. I noticed that although the flaps are animated, they have no effect on lift or drag. In fact they seem to work more like weak air brakes or spoilers. They even sent modified air and cfg files but nothing changed. Has anyone else had this happen?

[Willy]

Had a propliner once that when you hit the flaps would start to lose altitude until you raised them. The more you lowered the flaps the worse it was. There was eventually an updated flight model that fixed it.

[adhockey]

Had a propliner once that when you hit the flaps would start to lose altitude until you raised them. The more you lowered the flaps the worse it was. There was eventually an updated flight model that fixed it.

Isn't that the idea... flaps help you get your aircraft down? :redface:

[srgalahad]

Isn't that the idea... flaps help you get your aircraft down? :redface:

Flaps, although they sometimes do add lift (Fowler flaps in particular, by increasing wing area), are intended to increase drag. So, for any given power setting they reduce speed which allows for a lower approach and landing speed and/or steeper descent -for a given speed- WHEN you choose to go down.

USE OF FLAPS
The lift/drag factors may also be varied by the pilot to adjust the descent through the use of landing flaps.
[Figures 8-3 and 8-4] Flap extension during landings provides several advantages by:
• Producing greater lift and permitting lower landing speed.
• Producing greater drag, permitting a steep descent angle without airspeed increase.
• Reducing the length of the landing roll.
http://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/airplane_handbook/

This text (with pictures even) should be read by anyone who wants to master even the basics of flight. Of course, since it may point out many common misconceptions, those who only want to point-and-shoot should avoid this document.

[Sundog]

Flaps, although they sometimes do add lift (Fowler flaps in particular, by increasing wing area), are intended to increase drag. So, for any given power setting they reduce speed which allows for a lower approach and landing speed and/or steeper descent -for a given speed- WHEN you choose to go down.

USE OF FLAPS
The lift/drag factors may also be varied by the pilot to adjust the descent through the use of landing flaps.
[Figures 8-3 and 8-4] Flap extension during landings provides several advantages by:
• Producing greater lift and permitting lower landing speed.
• Producing greater drag, permitting a steep descent angle without airspeed increase.
• Reducing the length of the landing roll.
http://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/airplane_handbook/

This text (with pictures even) should be read by anyone who wants to master even the basics of flight. Of course, since it may point out many common misconceptions, those who only want to point-and-shoot should avoid this document.

Thanks for the reference. Downloading now.

Although, with regard to flaps, simple flaps add lift as well as they increase the camber of the airfoil. Witness "maneuvering" flaps on high performance aircraft. Of course, if you increase lift, you increase induced drag. It actually gets somewhat complex in designing aircraft as we typically optimize the airfoil for cruise, yet we wish to maximize L/D for take off (Take-Off flaps setting) and maximize lift (slow speed - Landing Flaps setting) on landing.

If anyone here is looking at learning some basic fundamentals with regards to doing some basic calculations, etc., I can't recommend this book enough; Aircraft Design: A Conceptual Process (http://www.aircraftdesign.com/book.html). I only wish he had published the first edition while I was in school. Much of it is very basic, so you don't need to know calculus to understand most of it. There's plenty of other great references at his website as well.

As for the flap aerodynamics in FS, you should be able to adjust those values in the config file. In fact, I need to do that on another aircraft I have, where, with full power and full flaps, the aircraft is unflyable due to it's excessive descent rate that develops as a result of all of the drag generated by full flaps.

[aeromed202]

I'm with everyone above. Flaps produce extra lift at the cost of increased drag, and enable slow flight. When flying straight and level at say 100kts, if one applies a notch of flaps, two things should happen. One-the aircraft should balloon a little, and two-airspeed should start to fall off.
With this particular model what happens is a simple pitch down effect. No ballooning to say extra lift has been applied, and no drop in airspeed to say drag has also been applied. I tried adjusting the flap values all over the place without any change in outcome. It will stall at the same airspeed, clean or full flaps. So I don't know what the deal is. Has anyone else seen this in this aircraft? I've gotten some CFS2 and 2002 aircraft to fly properly by grafting similar installers from newer planes. So where flaps didn't work before they do now sort of thing. I'll be trying some of those now.


So I tried using a negative cfg value for the lift_scalar and voila, I now have lift! I presume I can get the pitch and drag to behave by doing something similar to those numbers too. I'll be e-mailing this to PAD to see how they want to fix this little snafu.