No landing gear drag

[camg]

I have noticed that on a couple of add-on A/C (Beech Queen Air and Cessna P210) there is no airspeed reduction when the landing gear is lowered.

I checked both the .cfg and .air files. In the .air file 1101 Primary aerodynamics there is a value for gear drag. In the .cfg file there is a "gear system type" shown of either "0" or "1" (for electric or hydraulic).

I notice some .air files (like the P210 Duke B60 add-ons) also have a section 1004 in the .air file with values for "gear type" and "cycle time". But other aircraft .air files do not.

Any ideas on what needs to be changed or added to either file to get the modeling to show an airspeed decay when the gear is lowered?

Regards, Cam

[Tom Goodrick]

This is definitely a problem for some downloads. The cause is that the air file is based on an original aircraft that had fixed gear. There are details hidden within the air file that we do not have access to with any of the air file editors. Remember, all these editors were made by trial and error in dissassembly of the air file code. That is an imperfect process with something as complex as this simulator. It would be different if the original designers of FS would create a proper air file editor. Curiously, they (Bruce Artwick Associates) did have a good air file editor and Microsoft bought the rights to it but then dumped it. Microsoft does not know all the answers. They bought rights to the program from Bruce Artwick but he did not bother to point out all the details for them. They made their own editor using the aircraft.cfg files.

The only fix is to dump the air file and substitute an airfile for an appropriate "trusted" aircraft with retractable gear. Remember, the aircraft.cfg file supercedes the .air file in most respects where the two cover the same items. So most of the flight properties you have now with those aircraft will remain intact after the switch. But you can then adjust the drag coefficient and pitching moment coefficient in the .air file and then see the effects in slowing the aircraft and changing its trim slightly.

But, remember when editing either the air file or the aircraft.cfg file, you must swap out the aircraft for another and swap back again before you look for changes in flight.

The only items not covered by the aircraft.cfg file are the gear pitch and drag and the spoiler pitch, lift and drag. Actual coefficent increments in pitch, drag and lift for the flaps are presented only in the air file but are modified with scalars in the aircraft.cfg file.

[camg]

Thanks, Tom for the explanation.

The best match for an original .air file would be the FS2002 C-182RG--it's single-engine, high wing and retactable.

But I forgot if I can just load an FS2002 aircraft into FS2004. I seem to remember seeing a conversion file that would enable the C-182RG to be loaded in FS2004.

Will copying the 182RG directly into FS2004 work successfully?

Cam

[Tom Goodrick]

No. You will have a lot of work to do to get the C182RG flying right in FS2004. Use the Mooney for the single-engine aircraft and the Baron for the twin engine aircraft.

Guess what? I checked my Queen Air and it also had no gear drag! I thought I had checked that out some time ago but on that aircraft you put the flaps down first to slow to gear speed so I didn't notice the lack of gear drag because the flaps have plenty of drag. But I substituted the Baron's air file and it flew fine - after a little tweaking. I had to reduce the gear drag in the airfile, add some nose-down pitch and reset all the "tuning scalars" to 1.0 and then begin to readjust them. I found I also had the CG too far aft. My empty CG was at -0.5. When I loaded all the seats to get close to max gross, it sat on its tail with a CG at 38%. I moved the empty CG to 0 and it stayed flat on the gear but would not hold speed when I dropped the gear.

In this aircraft, the gear can come down only below 140 KIAS. The aircraft has enough angle of attack at that speed to have some induced drag. I already had flaps down to 15 degrees to hold 137 KIAS with some power. Lowering the gear, even with reduced gear drag from the original Baron's value, caused the trim to ride up to the max (using the autopilot to hold altitude). I had to move the empty CG to 0.2 in order to get fair speed stability with some power (nearly 50%). (Loaded CG moves back to about 29.5%.)

These adjustments typically take days to complete. I'll have to check cruise speed. In past cases I have not had much trouble switching .air files. But if the old airfile was heavily compensated by scalars, all bets are off. You have to go through each one.

I have piles of old aviation magazines around my desk and on book shelves and in boxes. I used to have an article on the Queen Air handy as were magazines for several recently acquired aircraft like Stone's models when he quit the business. But my wife suddenly had an attack of orderliness and revised the room. Now I can't find anything without considerable effort.

So it goes.

[camg]

You're right: the C182RG .air file doesn't work. I loaded James Joblon's C-182RG FS2002-to-FS2004 conversion files from Simviation. And while the C182RG seems alright, I get a aircraft loading failure on the P210 after I copy and rename the C182RG .air file to c210P and replace the original one with it in the P210 AC folder.

I don't know why the "converted" C182RG .air file will fly OK in FS2004, but it can't be copied and used in another FS2004 aircraft. On the way to an answer to one question comes 3-4 new questions!!

So will try the Mooney .air file next; thanks for the suggestion.

Regarding the Queen Air, I have a hardcopy of Flying mag's article on the A65 of Feb 1960 and the Queen Air 80 of June (I think) 1962. Also have the Jane's Aircraft specs on the 65, 70 and 80 Queen Airs. Let me know if you are looking for some specific data that I might look up for you.

Regards,
Cam

[Tom Goodrick]

There are several things here but to cut it short, I have FD files (aircraft.cfg and .air files) for the C182RG and for the P210 that work well in FS9. Send me an email and I'll send the two file sets by return email.

But, since you were red flagged for at least one of these, you will never be able to load them until you do some cleanup. That involves searching your system for the file fs9.cfg file that now contains a list of red-flagged or banned aircraft and erasing those entries.

When you try to load an aircraft from an earlier version or one that has had some custom work done on it, you will get a note saying thios is a BAADD file and may cause your system to go berserk. Do you want to avoid loading the trouble-causing files? If you are so unfortunate as to anwer this "yes" then the aircraft is put in the banned list and can never be loaded unless you find and erase the list. The location of that list depends on the version of Windows.

There was a major revision of aircraft modle data between FS2002 and FS2004. One change was wing incidence which no longer has any effect. The effect has to be created by shifting the lift curve (table 404) to the left so each value of lift coefficient occurs at a lower value of angle of attack. The bigest headache is the center of gravity. This has to be refigured for FS9. It is a big headache and involves some trial and error with some very strange results when you are off a little bit. Back when I was doing a lot of conversions, I could do most of the work in a couple hours. But the CG work always took many hours and sometimes a few days with plenty of extreme frustration. I have a CG gauge which helps. But you end up adjusting very slightly between nose buried in concrete and tail buried in concrete.

On the Queen Air 65, I need the stall speed in landing config and the normal cruise speed (giving altitude and power setting). (Which is the eight seat version, the 65?)

[camg]

I checked the fs9.cfg file and found two interesting things:

One is the [FrameCallNoWarn] header that has "Mu02b=0" and "P180 Avanti=0" underneath it.

The only other place in this file that mentions aircraft is the [AIRtoCONTAINER] section. It lists "sim1=Cessna Skylane 182R RG", then sim2 to sim6 for the Lear 45, 2-32 sailplane, Camel, and Extra respectively.

I don't see any AC by name in the rest of the .cfg file.

Does this mean anything to you?

P.S.--I e-mailed you Queen Air specs yesterday.

Regards,
Cam

[Tom Goodrick]

Just erase those lines for the MU2 and the Avanti and you will be able to load them. The "no warn" means those aircraft would not be permitted and you'd receive no warning. I don't know about the others but I'd erase the line mentioning the C182RG.

I have not yet seen the info on the Queen Air but my email has been strange since I started using two computers. I'll check with the other computer. Supposedly they both use the same account.

I'll send FD files for the C182RG and for the CP210.

[ben]

Dont have to change ac:

The 'trick' to not have to change ac is to use the
'Reload user aircraft'
keyboard assignment
-on my computer CTRL + SHIFT + R

This can be found under

Settings
CONTROLS ASSIGNMENTS
Event category
-All commands

Assignment list Keyboard Joystick
..
Reload user aircraft

Usually works :-)

[Tom Goodrick]

Cam I still have not received your email. Did you use the email icon under my photo? That should work. Yesterday something strange happened that caused a loss of several old emails from my system's memory. But I doubt if yours would have been among them.

[camg]

Tom:

I e-mailed you by using your address listed in the members information table. I was out of this forum website when in did it.

I'm at work now and the QA info is at home, so I'll send it again tonight using the e-mail icon here.

Regards,
Cam

[Tom Goodrick]

That is the correct address. The only thing is that clicking on the icon takes out the chance of a typo in the address. Perhaps you spelled hiwaay with one "a" or used .com instead of .net.

[camg]

The address looked OK, but I sent it once again, anyway.

I couldn't copy and paste into the e-mail started by the icon, so I'm pasting ithere as a reply in this string:

Hi, Tom:

The Queen Air 65 and A65 both had the same engines (340 HP), same wingspan and gross weight; the 65 had a straight tail and the A65 had a swept vertical tail.

It had 2 on the flight deck and 4-9 PAX in the cabin.

Clean stall was 82 knots and 70 knots in the landing configuration.

Flying Feb 1960 article for the model 65 noted 175 MPH indicated at 8,500 at 65% power.

Jane's A/C (about 1971) for the A65 listed max cruise of 186 KNOTS at 70% power at 15,200 ft.

Takeoff is at 3400 RPM and 48 in. Hg. and 80% power is 3000 RPM and 40 inches.

Critical altitude for the supercharger was 11,000 ft.

Regards,
Cam

[Tom Goodrick]

I am stumped on the email not showing up. I checked the trash bin for my antispam filter and did not find your email.

Thanks for the info. Is the Queen Air pressurized?

[camg]

Nope, you have to bring your own bottle if you're flying above 12,500 ft.