CRJ-200 Flight Tests - Report

[Guest]

[/p] [h2]CRJ-200 Flight Tests - Report[/h2]prepared by: Gregory Abbey 11-13-02 [/p] [/p] [/p] Thanks to everyone for the `real world' inputs. This jet is especially fun to sim-fly once you get it to behave [to your liking].. or should I say.. like it should..!! [/p] FedEx CRJ-200 feederhttp://www.edwinn.com/flightsim/FedEx_CRJ200.jpg [/p] [/p] [/p] CRJ-200 Virtual Cockpit[/font size] [/p] http://www.edwinn.com/flightsim/CRJ200_VC.jpghttp://www.edwinn.com/flightsim/CRJ200_VC-II.jpg [/p] [/p] [/p] Static pitch[/font size] On closer observation, the static pitch from the `port' side looks POSITIVE, and what happens inside is interesting as well. The nose tilts DOWN when takeoff thrust is applied..!!http://www.edwinn.com/flightsim/static_pitch_pos.jpghttp://www.edwinn.com/flightsim/static_pitch.jpgIn position and holdhttp://www.edwinn.com/flightsim/static_0kts.jpgTakeoff run - applying thrust pushes nose downhttp://www.edwinn.com/flightsim/static_135kts.jpg [/p] [/p] [/p]Forward view alignment[/font size] Here is an issue that is troublesome. If the panel direction values are boresighted (0, 0, 0) and the static pitch is NEGATIVE.. then how come the boresight 'v' pointer is above the horizon?? Could it be in the model itself?? panel.cfg[views]view_forward_windows=main_panelview_forward_zoom = 1.0view_forward_dir = 0.0, 0.0, 0.0 aircraft.cfg[contact_points]static_pitch = -0.750static_cg_height = 6.410 [/p] [/p] Boresight pointer should indicate below horizon - perhaps??http://www.edwinn.com/flightsim/alignment.jpg Default LearJet panel.. sender can't figure out why pointer isn't looking at runway..[/font size] [/p] [/p] [/p]Squirrely on ground[/font size] Have done some `hard steering limit' maneuvers on the field to check gear-strut compression. The model does `lean' and possibly the struts are working..!!http://www.edwinn.com/flightsim/cornering-01.jpghttp://www.edwinn.com/flightsim/cornering-02.jpghttp://www.edwinn.com/flightsim/cornering-03.jpg [/p] [/p] [/p]Aft starboard exhaust port[/font size] Is this the APU exhaust?http://www.edwinn.com/flightsim/APU_exhaust.jpg [/p] [/p] [/p]Climbout animation[/font size] (410k)http://www.edwinn.com/flightsim/CRL200_flyby.gif [/p] [/p] [/p]Changed the wing_pos_apex_lon distance[/font size] This was a lesson learned for the Lufthansa configuration of the HJG 707 study, setting the wing_pos_apex_lon distance as opposed to changing the cruise_lift_scalar. Sender has observed the following pitch angles with: wing_pos_apex_lon = 3.75[/font color] [/p] [/p] [/p] Results - Cruise Pitch[/font size] 250 kts at 11,000 fthttp://www.edwinn.com/flightsim/CRJ200_pitch_250kt.jpg 290 kts at 11,000 fthttp://www.edwinn.com/flightsim/CRJ200_pitch_290kt.jpg 330 kts at 11,000 fthttp://www.edwinn.com/flightsim/CRJ200_pitch_330kt.jpg [/p] [/p] [/p] Scaling the bird[/font size]Analysis to find wing location and angle.. and hence the lift centroid.http://www.edwinn.com/flightsim/CRJ-200_top.gif Note: vertex_lon and apex_lon used interchangeably..[/font size] [/p] This is a scaled `screen cap' as viewed from directly above, so it may be slightly different from the real plane. From this analysis comes: * Root_chord -- 14.43 ft * Apex_lon -- 5.88 ft * Wing_sweep -- 27.11 deg [/p] [/p] [/p] Approach angle[/font size] Approach angle indicates between -2.0 and -2.5 degrees, however the boresight pointer appears to be only a fraction of a degree negative. It would seem [that] the pitch angle is added to the descent angle (have not confirmed).http://www.edwinn.com/flightsim/approach_nonums.jpg [/p] [/p] [/p] Great virtual cockpit[/font size]This model has the best and most useable virtual cockpit that sender has ever seen. Normally, one would wish there was none, some of them are so badhttp://www.edwinn.com/flightsim/CRJ200_virtual-I.jpghttp://www.edwinn.com/flightsim/CRJ200_virtual-II.jpg [/p] [/p] [/p] Summary[/font size] The final aircraft.cfg entries after fight-test runs which confirm the new values `did work'. Here are the critical sections of the configuration:[flight_tuning]cruise_lift_scalar = 1.00 // 0.93 // 1.191 // 1.211 // 1.0parasite_drag_scalar = 1.00 // 0.977 // 0.953 // 0.91 // 1.0induced_drag_scalar = 1.0elevator_effectiveness = 1.0aileron_effectiveness = 1.50rudder_effectiveness = 1.0pitch_stability = 1.200 // 1.400 // 1.0roll_stability = 1.0yaw_stability = 1.0elevator_trim_effectiveness = 1.0aileron_trim_effectiveness = 1.0rudder_trim_effectiveness = 1.0[airplane_geometry]wing_area = 625.00wing_span = 75.00wing_root_chord = 14.43 // 8.85wing_pos_apex_lon = 5.88 // 2.75 // 0.00wing_pos_apex_vert = 0.00wing_sweep = 27.11 // 24.76wing_dihedral = 2.33wing_incidence = 0.50 // 1.00 // 0.50 // 0.000wing_twist = -1.00 // 1.000oswald_efficiency_factor = 0.82 // 0.80 // 2.500[weight_and_balance]reference_datum_position= 0.000, 0.000, 0.000empty_weight_CG_position= 0.000, 0.000, 0.000max_gross_weight = 51250.0empty_weight = 30900.0//empty_weight = 39000.0 // LR//empty_weight = 44000.0 // ERstation_load.0 = 1200.0, 12.000, 0.000, 2.000station_load.1 = 1200.0, 6.000, 0.000, 2.000station_load.2 = 1200.0, 0.000, 0.000, 2.000station_load.3 = 1200.0, -6.000, 0.000, 2.000station_load.4 = 1200.0, -12.000, 0.000, 2.000[jet_engine]thrust_scalar = 1.1625 // 1.00 // 1.1625[autopilot]autopilot_available = 1flight_director_available = 1autothrottle_available = 1autothrottle_arming_required = 0autothrottle_takeoff_ga = 1autothrottle_max_rpm = 104.0 // 102.0 // 105.0 // 95.0 // 105.0pitch_takeoff_ga = 8.0default_vertical_speed = 800.0use_no_default_pitch = 1 // 0use_no_default_bank = 1 // 0 [/p] [/p] [/p] Reset to 1.1625x thrust[/font size]Also went back to 1.000 for parasitic and induced drag scalars. So here is some Flight Level 33,000 engine data at various cruising speeds with 9,000 lbs payload and 45% takeoff fuel at 1.1625x thrust. Mach pitch N1 ITT N2 FF EPR EGT 0.74 1.25 91 668 90 1164 0.97 318.7 0.76 1.07 92 677 91 1230 1.02 324.2 0.78 0.89 95 690 92 1300 1.09 331.9 0.80 0.76 98 734 95 1382 1.16 339.0 [/p] [/p] [/p] Note: please reply with improvements or if this configuration is not working well. Content is for development purposes and subject to change.[/font size] [/p] Gregory Abbey - Edwinnengineering[/font size]

[John_Cillis 2,406]

One question... Why the "//" in the aircraft.cfg entries? Normally they denote comments...Can't wait to try this later on...-John

[Guest]

>One question... Why the "//" in the aircraft.cfg entries? >Normally they denote comments... >>Can't wait to try this later on... >>-John [h3]the '//'s[/h3]I think you mean the //'s in between the data .. that is whenever you go to validate a different number .. you shift the others to the right to retain you `tuning history'. Is this what you were asking??Gregory Abbey - Edwinnengineering

[John_Cillis 2,406]

Yep...I've always been a sloppy tuner... I'd make the changes, and hoped they'd work without my having to remember what I'd done.Then again, when I code, I'm terrible about including comments as well :)

[Guest Shane Strong CYHZ]

so me being a little slow here what should we change to get the better preformence

[Guest]

>so me being a little slow here what should we change to get >the better preformence Hi Shane..What to change[/font size]I was not going to get into advising on this .. in that you all could look it over and decide. But since you asked .. here goes:1) First thing are the wings. I do not believe the wing_twist is in reality positive (UP at tips) with a 0-deg root angle (no manuals or drawings however). It is now +0.5 deg UP at the root with a -1.0 deg NEG twist so the tips are DOWN slightly..!!2) Unless I'm missing this one badly .. the wing efficienct range is from 0.0 - 1.0 and I assume anything over 1.0 is simply 1.0 (again no docs). The wing efficiency is now 0.8203) Now that the mean lift vector is twisted forward (by twisting the tips down) and the lift is cut slightly (less efficient) .. the lift centriod is moved forward based on `scaleing the bird' (see drawing). The wing_ apex_lon is now 5.88 ft instead of 2.75 ft ahead of the 1/4 root chord location. The root chord is set to 14.43 instead of 8.85 (distance where wings join fuselage). [/p]Summary thus farWings twisted down and lift vector rotates towards nose. Lift cut slightly by reducing efficiency from 100%. Wing lift centriod move forward along the fuselage and root chord increased (longer - where wing meets fuselage). Now if you wish to change cruise pitch, edit cruise_lift_scalar. NEG means `higher nose' and increasing POS means nose `pitches over'.4) Wing_sweep increased to 27.11 degrees based on `scaling the bird' (see drawing) for an increased angle aft (it's the mean angle).5) Pitch_stability increased slightly to 1.200 to keep pitch from `hunting' and damp undulations such as when reaching cruise altitude.6) Finally, the correct empty_weight of 30,900 lbs. substituted and some station loads added (distributed in longitude - no drawings) to represent somewhat correct passenger and baggage load (ZFW). Also affects lon_MOI.Note: no data on fuel usage or range. [/p]After all this .. the model seems to fly with the correct cruise pitch now.(see FedEx pitch angle in pic at top of report..) [/p] [/p]That about does it, but the thrust_scalar still bothers me. It cannot `fly high' with correct engine thrust (scalar = 1.0) and this may make it `too hot' off the runway (cannot confirm - only speculation). [/p] [/p]DisclaimerSender is not a pilot and has no CRJ manuals - content is not necessarily tuning advise and user makes changes at own risk. CFG settings are NOT official or certified as correct or accurate and are for development purposes and sim-flight tuning studies only..!! [/p] [/p]Enjoy.. and let us know it you found better settings..!! [/p] [/p]Gregory Abbey - Edwinnengineering

[Guest]

Does anyone else think that the control columns and the seats are way too far back from the panel? It looks like you'd have to have some very long legs to reach the pedals! Just trying to make a good plane better.

[Guest]

I just put the falcon50 airfile in it. Flies great. Just needs some trim up for takeoff.

[Guest Shane Strong CYHZ]

why dont you open your own fourm on air craft flight dynamics and editing i am sure we could use one here shane

[Guest P3_Super_Bee]

You know what, I never post these threads, but just have to on this one after the about the 3/4th one like this. If you are such an aircraft design expert, let me ask this...How many FS aircraft have you designed?How many Fs aircraft that you have designed have been downloaded?Didn't waste my time in doing any searches but I'm bettin' my answer is correct, my appologies if wrong. answer to question 1 = ZEROanswer to question 2 = ZEROIf youyur such the expert I'm also willing to bet you shelled out the bucks for the FS2KS "Professional" (since this seems to be what you think you are) Here's a little tip. FS2K2 came with a little program called GMAX. How about Shuttin' up and start puttin' out.This is why these threads get deleted Ole Mister "I know better than all" comes in tells these guys (not just Posky all designers) you all screwed up do it this way, do it that way, that rivet is out of place, if that were a real plane, that rivet placement there wouldn't cause that there dirt mark you've painted it fix it yesterday.From what I've seen when someone comes in and asks questions nicely not in the "I'm the God knowing all" tone. Most developers if not all answer and try to fix flaws as TIME permits.:-outtahttp://publish.hometown.aol.com/p3superb/images/675-2fs.jpg

[John_Tavendale 453]

For anyone who is trying these new 'tweaks' let me advise you Don't come moaning to us if you stuff something up

[SAS263 1]

Jeff and John: Why the hostility? I suspect that I

[Guest]

So what if the guy doesnt design aircraft. Do you? I have never seen anything from you Mr. Frey, accept for your two splash screen entries. WOW! Your attack on Gregory is unfounded. What is your basis for your attack? The only thing Gregory has done is figure out that some things are a little askew with the POSKY CRJ and provided that information to the rest of the simming community.Some of you think you are "The almighty", and you are not.And before you ask, no I have not designed any aircraft, and I dont want to design aircraft, and I have made no contributions to the simming community, and I have yet to see anything from you, other than posts and splash screen...be still my beating heart.

[Tom Allensworth 1,532]

Okay, this has gone south and is now locked.