Elevator Lock up?

[Piglet]

Hi All,
I'm trying to make an airfile for my latest project. I want to give it a F-5E type flight permormance and dynamics. Problem is the elevators lock up after breaking 500-550 knots. Still have roll control,tho.
I'm using Flight Workbook version V2005.10, from Jerry Beckwith
Hopefully, the solution will be not too hard!:jump:

[Wozza]

Hi Mate
Section 517 is prob. rolling off a tad to soon (elevater ver dynamic pressure or something like that)
X is speed Y is elevator movment In laymens terms,Im sure the boffins have a more tech name for em :)

cheers
Wozza

[fliger747]

Piglet:

I have had a similar RUDDER problem using the workbook and Airwrench. It was not an airspeed problem, but a mach response problem. I (finally) went and stole a table out of a plane that did work at higher Mach numbers.

Check and see if the behavior is different at low altitude and high altitude! I use the ASFD instrumtation to check at what speeds/Mach I was losing control response (went to zero).

Good Luck!

[Piglet]

I went back to Workbook Version 3.00.09. It seems to behave better than the last versions. Still get elevator lock-up, but not as bad. I also used it for the Mohawks. It might just be me, but I seem to have too much trouble with the latest FDWB releases. This is also strange, in that I used an earlier version for my X-24A, and that had no lock-up problems. Ummmm.....

[fliger747]

It would appear that some of the formula used for calculating the tables may be optimized for subsonic aircraft with non powered or non irreversable powerd flight controls. In transonic and supersonic capable aircraft with augmented flight control setups, another approach may be necessary.

Not an area of MSFS flight dynamics with which I am very familiar. Still struggling along with some transonic problem of my own!

Keep us posted as to your progress!

[Farmboy]

Hi All,
I'm trying to make an airfile for my latest project. I want to give it a F-5E type flight permormance and dynamics. Problem is the elevators lock up after breaking 500-550 knots. Still have roll control,tho.
I'm using Flight Workbook version V2005.10, from Jerry Beckwith
Hopefully, the solution will be not too hard!:jump:

When you say "lock up" do you mean that at that airspeed, the elevators no longer have any effect? If that is the case, most likely it is as stated earlier, Section 517 rolls off too quickly. What you've got there is a lookup table that reduces control authority with dynamic pressure, and if you can figure out what that value is at the highest possible IAS for your plane you can probably come up with something that will work. If you look at Section 517, you will find five entries in an X/Y table. The X value is Q (dynamic pressure) and the Y value is a unitless number that represents that table's effect on the control authority specified in Section 1101 for elevator authority. Set all Y values to "1" and see if you get any better control. If not then you will need to start looking at the Mach # lookup tables, which gets more complicated as there are several of these that can affect elevator authority with aircraft speed.

You can safely delete many of these lookup tables and the sim will then use calculated default curves, which often work quite well. Try deleting Sections 517, 518, and 519 and see what happens. Also review Sections 410, 412, 420, and 422, all of which affect elevator authority and pitch stability vs. Mach #, and be prepared to spend many, many hours testing at both high and low altitudes.

Unfortunately, I must warn you and anyone else involved in this hobby that it can take a serious toll on your health. After years of spending many hours on end manipulating a mouse and joystick, I've developed "Golfer's Elbow" (tendinitis) in my right arm. Not a good thing, it can take months to heal and really tends to cramp your style in a lot of other areas of life. Taking a lot of breaks and keeping the arm in motion by flexing it can help a lot. Being young doesn't hurt, either, but it's no guarantee you won't develop the problem.