B-52s Sink into the ramp Tail First

[John Young]

I got there in my 18 Sep post. The centre of gravity is probably in the wrong place for a user flyable aircraft. What happens if you move it as suggested?

John

[wbunnell]

All My MAIW Aircraft Are downloaded into a file “MAIW files opened”, on my desktop in their original format. I then Change the, JMAI headings to USAF. If there is a problem like the way I’m having now, I reload the original aircraft in the “MAIW files opened” folder.
Like I said in my last post, All the B-52s from JMAI fall tail first through the ramp” even after I replaced them with original files.
If as for me being the only one that has that has a problem, I guess I’m blessed.
Why would all of the B-52s made by JMAI have the same problem, yet the KC-135s don’t? Maybe I should quit doing what I have been doing for about 14 years or longer, and just except no one knows how to correct the problem.
Other people probably, know how to correct the problem, I don’t!

OK lets move all those B52 folders that you have installed to another part of your PC, so that FS can't see them.
Now extract one of Mike's packages to your manual folder. There is nothing wrong with that, I always prefer to do manual installations.
Now lets leave any alteration of Mike's original files for the moment, this is only to eliminate any possibility of problems at all.
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So which pack are you installing and which base are looking at the aircraft on the ground when they fall through the ramp? I want to do a check myself to see what I get.

I am using a modified KELY. Its modified to include a large ramp opposite runway from control tower view location.

I use this airfield to size my aircraft, and see what an aircraft looks like.

I have been using this airfield for 10 or more years, with no issues.


As for the aircraft in question, they are all of the aircraft from the JMAI B-52 traffic files. They are kept in a separate file on my desktop
All the MAIW_JMAI KC-135 files work with no Problems.

[wbunnell]

I got there in my 18 Sep post. The centre of gravity is probably in the wrong place for a user flyable aircraft. What happens if you move it as suggested?

John

I have changed the cg, from 21 to -21 to +85, still getting same results.

[Firebird]

Does this happen when you select the plane to fly it, or when you just select the base and go there, or both?

[John Young]

Moving the CG to +110ft will put the aircraft level on the runway. The screen shot below has the aircraft set up as a flyable aircraft and it's stable:



However, trying to fly it from there is a no go. The aircraft stays level for the take-off run, but then pitches backwards after rotation. Further movement of the CG can't correct that.

As we've said before, the FDE is set up for an AI aircraft and that's radically different from what's needed for a user-flyable aircraft. In some cases, the FDE can be re-worked if you know what you are doing and my next step would be to recalculate the Moments of Inertia for a flyable aircraft. However, the FDE is so way out for that purpose, "Airwrench", the tool I use for FDE work, won't even allow me to open the .air file. It just reports "an invalid argument was encountered".

So, changing the CG to +110ft will put the aircraft level for "user-flyable" ground test purposes, but forget about trying to fly it. This will wreck the AI performance of course, so remember to restore the CG to +21ft for that purpose.

John

[wbunnell]

Does this happen when you select the plane to fly it, or when you just select the base and go there, or both?

I don’t want to Fly these aircraft, I use them more to Select correct aircraft for missions.

[campbeme]

Select aircraft for missions but not flying? I'm more confused, than before now sorry.

[wbunnell]

Moving the CG to +110ft will put the aircraft level on the runway. The screen shot below has the aircraft set up as a flyable aircraft and it's stable:



However, trying to fly it from there is a no go. The aircraft stays level for the take-off run, but then pitches backwards after rotation. Further movement of the CG can't correct that.

As we've said before, the FDE is set up for an AI aircraft and that's radically different from what's needed for a user-flyable aircraft. In some cases, the FDE can be re-worked if you know what you are doing and my next step would be to recalculate the Moments of Inertia for a flyable aircraft. However, the FDE is so way out for that purpose, "Airwrench", the tool I use for FDE work, won't even allow me to open the .air file. It just reports "an invalid argument was encountered".

So, changing the CG to +110ft will put the aircraft level for "user-flyable" ground test purposes, but forget about trying to fly it. This will wreck the AI performance of course, so remember to restore the CG to +21ft for that purpose.

John

I guess I didn’t go far enough forward with the cg, 85 didn’t even indicate any movement of the backward move slower.
I thank you, and everyone else that tried to correct this problem.

[John Young]

Yes I was surprised at the amount of shift in the CG required, even though the aircraft is 159 ft long. Then I realised that the brake chute is also probably taken into consideration too. That extends back another 90ft or so.

John

[wbunnell]

When trying to use aircraft for ai, after moving CG at 110 to get visual view B-52 aircraft from JMAI, will cause the aircraft to fall through the ramp.

[John Young]

You're still not grasping the problem. So I'll reiterate the key point.

The required FDE set up for this AI aircraft is different for a user-flyable aircraft. That's often the case.

Moving the AI CG by +110ft is necessary to give you a balanced "flyable" aircraft with selection through the FS9 aircraft menu if you have enabled aircraft type to "0" in the .air file. However, as I said before, that will wreck the AI FDE.

To use the aircraft as AI again, you must shift the CG back again.

If you want both the "flyable" and the AI aircraft available at the same time in FS9, you must set up the "flyable" aircraft in a separate folder with it's own FDE (CG shift), with a different aircraft identity.

You have to weigh up the hassle you are creating for yourself in order to use the aircraft in a way the author never intended it to be used.

John

[Garysb]

Apart from that is he on FSX?

[wbunnell]

When trying to use aircraft for ai, after moving CG at 110 to get visual view B-52 aircraft from JMAI, will cause the aircraft to fall through the ramp.

This a FYI, specifying for people who want to have aircraft to be visiable!!!

[John Young]

Didn't I effectively say the same thing 3 days ago ?

"This will wreck the AI performance of course, so remember to restore the CG to +21ft for that purpose"

Time we dropped this one I think.

John

[VulcanDriver]

When trying to use aircraft for ai, after moving CG at 110 to get visual view B-52 aircraft from JMAI, will cause the aircraft to fall through the ramp.

This a FYI, specifying for people who want to have aircraft to be visiable!!!

In that case you need to use AI Hide (bbqhideai.zip on AVSIM) that can make AI aircraft visible in the menu without the need to edit any files yourself. I use it to hide AI aircraft so FS loads faster.