Help adjusting FDE please?

[martinstebbing]

Simple as that. PITCH TRIM. OK? OK!

 

Not really OK, no: "bogus suggestion", in fact - because as the nose lowered with trim, the plane of course lost lift and so immediately went into a stall - that's at 155kts, almost no fuel or cargo and full flaps!

 

With the lift_scalar now set to 1, the plane behaves just fine, as I have said, and I can approach at a proper speed (around 130kts) making the usual small trim adjustments as necessary to maintain a good descent profile.

 

Thanks anyway.

[napamule2]

So now you have TOO MUCH lift and need to 'trim' (probably negative) to maintain profile?

 

I am being sarcasstic. No '0.400' change in 'lift_scalar' will make THAT much difference.

Chuck B

Napamule

[Capt_Flappers]

No '0.400' change in 'lift_scalar' will make THAT much difference.

Chuck B

Napamule

 

in fs9 config files 0.400 is a 40% change

[napamule2]

In FS98, FS2000, FS2002, and FSX cfg files '0.400' is ALSO equal to 40% change. But 40% change of WHAT? And since your flaps's lift, drag and pitch are dependent on what is in the air file, then you can argue all day about '40%'. But you can't leave out the air file ingredient or your calculations won't make any sense. I wish people would stop tweaking the dynamics by using the 'Flight Tuning' and other non relevant sections of cfg while ignoring the air file sections that have a DIRECT, and ABSOLUTE, bearing on results. Just saying.

Chuck B

Napamule

[keefpee]

But then I find using the flight tuning useful for easily adjusting a parameter, but afterwards I then adjust the air file value by the new percentage used in the cfg. ( I do it this way because it saves doing a reload because the cfg file is uploaded to the aircraft in use, so one can just reselect the aircraft, whereas the air file needs to be read from the loading of FS9 or FSX).

Keith

[Capt_Flappers]

you can argue all day about '40%'.

 

I'm not arguing about anything, I'm simply pointing out to folks who may not be familiar with and are trying to learn, what the values mean in the cfg files. .4 or .5 or .6 sound like very small numbers, but it could have a big impact when you realize it is actually 40 or 50 or 60 percent.

[martinstebbing]

I must be missing something - where did 40% come from all of a sudden? Are you referring to the change suggested in pitch_scalar from 1.0 to 0.6? I changed lift_scalar from 0 to 1 and the difference is more than enough to make the a/c fly just fine... A change in pitch_scalar made no appreciable difference.

[Capt_Flappers]

I must be missing something - where did 40% come from all of a sudden? Are you referring to the change suggested in pitch_scalar from 1.0 to 0.6?

yes, I just wanted people to understand, if they didn't already, that the decimal numbers in the .cfg files represent a percentage, with 1.00 being 100% and .6 being 60%, so that would be a change of 40%, which could make an appreciable difference depending on the starting value that is in the .air file.

[napamule2]

Argue? No neeed. Just the facts or the approximate fact? Read on...

 

Flap 'scalar' of 1.0 is NOT 100% of anything. It is the 'default' scalar for modifying what

is in the air file. Is 2.0=200%. NO. It's TWICE the 'scalar' in relation to 1.0.

 

The "lift factor" could be increased, say to 2.0, to give more flaps lift at the same

airspeed to reduce the descent rate.

 

The "drag factor" can be increased to reduce airspeed at a given descent rate

 

The "pitch factor" can be used to increase or decrease the pitch up or down angle

induced by the flaps lowering. Adjusting this can help reduce the amount of manual

or trim pitch you need to apply in landing configuration.

 

For example, a scalar of -0.049 pitch scalar (depending on type of aircraft) will produce a slight negative pitch which is induced linearly from time of start of flap extension and tapering off at the point of full deflection (BUT... it depends on initial pitch, and amount of throttle, which also makes the current speed a factor). In other words if you are at stall speed (cruise or approach) it's too late - nothing will be 'modified'. But if you are coming in too fast (high speed) the scalar will make little or no difference as to what effect flaps will have on that speed/descend rate. Got a headache yet? Sorry.

Chuck B

Napamule

[tgibson_new]

Um, 200% *is* twice as much. Do you not know percentages?

[napamule2]

The point is that 0.60, 1.00 or 2.00 SCALAR (as values) do not produce a linear result or effect. That is the crux of the matter. If they were linear then yes. But they are not, so no.

Chuck B

Napamule

[Capt_Flappers]

cut and paste from FS9 SDK: For example, a value of 1.1 increases the effectiveness by 10 percent. Likewise, a value of 0.9 decreases the effectiveness by 10 percent. A negative number reverses the normal effect of the control. Omission of a parameter results in Flight Simulator defaulting to a value of 1.0