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CRJ700 nose down fix


Double J

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If you want to experiment, try changing the values here:

 

;Moments of Inertia

empty_weight_pitch_MOI = 413776

empty_weight_roll_MOI = 188879

empty_weight_yaw_MOI = 578254

empty_weight_coupled_MOI = 0.0

Still thinking about a new flightsim only computer!  ✈️

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I beg to differ. The default FSX CRJ-700 does NOT fly 'nose down' (so it doesn't need 'fixing'). Here is pic showing it in flight.

Chuck B

Napamule

FSX CRJ_Nose Pitch.jpg

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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I beg to differ. The default FSX CRJ-700 does NOT fly 'nose down' (so it doesn't need 'fixing'). Here is pic showing it in flight.

Chuck B

Napamule

 

You can beg all you want. My eyes work fine and compared to the other default AC in my FSX ..it does. Empty or full, fast or slow.

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Well, either you 'messed' with the aircraft cfg, or you are flying it at either 100% power or at 10% power, or you are flying it over Australia (just kidding). Let's see a screen shot of the CRJ in profile (AP alt hold on, 65% N1, at 4,500 ft). Standing by...

Chuck B

Napamule

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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If you want to experiment, try changing the values here:

 

;Moments of Inertia

empty_weight_pitch_MOI = 413776

empty_weight_roll_MOI = 188879

empty_weight_yaw_MOI = 578254

empty_weight_coupled_MOI = 0.0

 

I tried 350000 and 450000 , no diff.

 

It does look level at 7000 ft but who cruises at 7000? Up at 35000 doing 250KIAS it's definitely nose down.

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Sorry, that adjustment didn't help....just my best guess.

 

I did a test flight from KLAX to KLAS with a cruise altitude of 30,000 and a speed of MACH .68 or 260 KIAS.

 

This is at cruise altitude.

 

CRJ at cruise.JPG

Still thinking about a new flightsim only computer!  ✈️

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Why did you change it to that paint job? Looking to spice things up on the topic? ;)

 

CRJ at cruise-2.jpg

 

Me, when I have doubts and see drooping noses I do the vertical line against the engine cowling to check. Where did I get that? No clue now. My German (AZ) is gaining on me probably.

 

Unfortunately, this can only be fixed on the aircraft verboten (ops!) forbidden files. OP should try another manufacturer and compare.

 

Cheers,

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Changing MOIs will just change the amount of force required to move the aircraft in a particular axis.

 

To quick fix an aircraft cruise attitude, to whatever makes you happy, can be achieved by changing the following in the aircraft.cfg file (make backups...yada...yada).

 

[flight_tuning]

cruise_lift_scalar = 1.0

 

If you lower that value by a small amount, the aircraft will have to be more nose up to achieve the same amount of lift (effectively giving it a more nose-up attitude at cruise). If you raise that value, the aircraft will cruise more nose down. Adjust it to suit your taste.

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Double J,

Ok, you were right. It does cruise nose down. So I made changes. Took Jordan Moore's advice. Made cruise lift=0.8. But that alone only helped a little. So I also changed the 'htail incidence' from '4.0' to '-0.395' (in airplane geometry) AND changed engine vertical position from '2.1' to '-1.0'. That did the trick. And (my pet peeve) the pitch trim on cruise is not '-1.2' anymore, but '0.0' (ha). Here are BEFORE and AFTER pics.

Chuck B

Napamule

FSX CRJ_Nose Pitch 1.jpg

FSX CRJ_Nose Pitch_Level.jpg

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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Double J,

Ok, you were right. It does cruise nose down. So I made changes. Took Jordan Moore's advice. Made cruise lift=0.8. But that alone only helped a little. So I also changed the 'htail incidence' from '4.0' to '-0.395' (in airplane geometry) AND changed engine vertical position from '2.1' to '-1.0'. That did the trick. And (my pet peeve) the pitch trim on cruise is not '-1.2' anymore, but '0.0' (ha). Here are BEFORE and AFTER pics.

Chuck B

Napamule

 

that works good.

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maybe,

You do realize that this is the FSX default CRJ-700 and that it is messed up don't you? At 37500 ft you will get porpoise (bad). So what's the use. Right? Right! But, butt, cigerette butt... I worked on it and I FIXED IT. Flys level and smooth as silk, even at 41500 ft.

 

Yesterday was 'payday' (and 'paybills' day) so was busy. But I worked on it last night and a couple of hours this morning. It's 99.999%. The lines I made on pic are LEVEL. I used Photo Suite program feature. Here is pic.

Chuck B

Napamule

FSX CRJ_Nose Pitch_FL375.jpg

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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It is mabe,

 

I didn't imply anything except cruising at 15,000 wasn't telling much. Normally cruising with this type of planes is in the upper 30,000's or at the very least least upper 25,000's. I don't complain much about MS-FSX default planes as much as I do with others very well known that I just can't stand even though they are gorgeously looking ones standing on the tarmac. Just don't try to taxi/fly them.

 

As for the porpoise effect, I use FSX-Dlx+Sp1+Sp2 rather than FSXA. I own them both BTW but I went back to FSX-DLX to avoid the dreadful effect as much as possible and easily. For long haul flights I use x16 and the porpoise effect is not acceptable.

 

Thanks for the picture and I will give your fix a try next time I stop in the CRJ-700 again. It might also fix a group of old DC-10's which I always thought they were too much nose up while cruising in the upper layers. Now, I am having fun with the Sukhoi S100 and the venerable B757.

 

Cheers,

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Ok, mabe,

Well, the 'fix' was only for the 'nose down' problem and did nothing to fix the porpoise effect at FL375. The fix for THAT involves a lot of changes to cfg and air file. Not done with it yet. Have a Auto Throttle 'problem', a flaps 'problem', it's TOO fast (goes Mach 1.15) and it TOO sensitive as far as trim pitch and elevators is concerned (that results in impossiblility to do ILS landings). No bueno. So it's more like 90.9%. News at 11.

Chuck B

Napamule

i7 2600K @ 3.4 Ghz (Turbo-Boost to 3.877 Ghz), Asus P8H67 Pro, Super Talent 8 Gb DDR3/1333 Dual Channel, XFX Radeon R7-360B 2Gb DDR5, Corsair 650 W PSU, Dell 23 in (2048x1152), Windows7 Pro 64 bit, MS Sidewinder Precision 2 Joy, Logitech K-360 wireless KB & Mouse, Targus PAUK10U USB Keypad for Throttle (F1 to F4)/Spoiler/Tailhook/Wing Fold/Pitch Trim/Parking Brake/Snap to 2D Panel/View Change. Installed on 250 Gb (D:). FS9 and FSX Acceleration (locked at 30 FPS).
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Dunno.. I just tried it out here being curious, and I don't see a pitch down at normal

cruise speed. It's a tad more level than I would normally expect, but judging from the

upper roofline vs the horizon, it's not pitch down. At FL390 at mach .79, I'm actually

a teeny bit pitch up. Just barely though. No porpoising here at all. So they may be due

to the changes made, along with it seeming to be overpowered. It may be a tad

overpowered, but I'm not sure what the real plane would see at that level and speed.

I'm doing N1 of around 74.5 for mach .79 at FL390. Which is lower than the 737 would be,

but being I don't know anything about the CRJ should be doing in such a case.. ???

 

Also, wonder about the speeds.. Normal cruise in the upper flight levels would be about

the same as a 737.. IE: mach .78-.79, and max cruise is mach .825.

Mach .90 is way over speed, and that could cause a slight pitch down vs normal speeds.

Also a IAS of 330 is very hot at the lower altitudes. And that could cause an abnormal

pitch down vs more normal speeds.

This is the pitch I'm showing at FL390 at mach .79, which would be a fairly normal alt and

speed. I noticed the "MACH" setting on the PFD and AP setting does not work properly,

and does not show the set mach speed.. I can only get it to show the set IAS even if

MACH is selected on the MCP. Which is irregular and doesn't seem right.. :(

But about semi typical for a default FSX jet and autopilot.. :p

 

crj700.jpg

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Double J,

Ok, you were right. It does cruise nose down. So I made changes. Took Jordan Moore's advice. Made cruise lift=0.8. But that alone only helped a little. So I also changed the 'htail incidence' from '4.0' to '-0.395' (in airplane geometry) AND changed engine vertical position from '2.1' to '-1.0'. That did the trick. And (my pet peeve) the pitch trim on cruise is not '-1.2' anymore, but '0.0' (ha). Here are BEFORE and AFTER pics.

Chuck B

Napamule

 

 

Did you happen to try taking off with the plane after you made the adjustments..LOL took off at 50knts went straight up.

 

This plane is AI and nothing more.

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don't see any issue.

All level flight. Default aircraft, no edits.

 

25.000 M0.71

[ATTACH=CONFIG]177223[/ATTACH]

 

[ATTACH=CONFIG]177224[/ATTACH]

 

31.000 ft, M0.79

[ATTACH=CONFIG]177225[/ATTACH]

 

[ATTACH=CONFIG]177226[/ATTACH]

 

39.000ft, M0.83

[ATTACH=CONFIG]177227[/ATTACH]

 

[ATTACH=CONFIG]177228[/ATTACH]

 

 

Sure hope you don't build houses for a living.

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