UAL Bagsmasher
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Posts: 1839
Joined: Wed Sep 08, 1999 12:52 pm

CRJ-200 NWS Problem

Sun Apr 08, 2007 8:55 am

Ok all you CRJ-200 mechs, time to pick your brains. We have a CRJ-200 that pulls to the right when taxiing. No steering inop EICAS messages have ever been shown. Nothing is flagged in the ECU. The RVDT's are in rig. The aircraft has been jacked and the brakes aren't dragging. The Steering manifold and EHSV have been R&R'd with no luck. The R/H RVDT has been R&R'd with no luck. A new ECU has been slaved in with no luck. A new Tiller has been slaved in with no luck. Both engines have been tested for Accel/Decel rates and have passed. The NWS harness has been ohmed out and Megged, both while being shaken, and it has passed. Both NLG tires have been R&R'd with no luck. As of right now, the SSV is being changed, followed by both actuators. What the heck else is left in the system that would cause the aircraft to veer to the right(only) while taxiing? The drift is not violent, but it is noticeable and unacceptable. Every other time I've seen this problem, it ended up being an EHSV or RVDT at fault. We're sick of looking at this lawn ornament. Maybe it's time to call our friends over the border for an action plan...Any ideas?

[Edited 2007-04-08 02:07:59]
 
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HAWK21M
Posts: 29867
Joined: Fri Jan 05, 2001 10:05 pm

RE: CRJ-200 NWS Problem

Sun Apr 08, 2007 11:06 am

Tire Pressure.
Oleo Extensions.
Rigging.
What does the Isolation manual state.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
radialman
Posts: 32
Joined: Sat Aug 11, 2001 3:39 pm

RE: CRJ-200 NWS Problem

Sun Apr 08, 2007 12:20 pm

Is there any difference with the steering switched off while doing a taxi test.
What are the codes from the ECU.- AMM Task 32-50-00-740-801 and AMM Task 32-51-10-700-801.
 
UAL Bagsmasher
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Joined: Wed Sep 08, 1999 12:52 pm

RE: CRJ-200 NWS Problem

Mon Apr 09, 2007 9:17 am

Update. The SSV was changed last night and was a no fix. First thing this morning we consulted Bombardier and requested an Action Plan. They recommended changing the NWS harness, as they have seen this exact symptom before as a result of a faulty harness (even though it had ohmed and megged good). So we change the harness. Next thing you know, the LFT RVDT won't hold a steady rigging. As we examined the LFT RVDT, we wiggled the braided cable hooked to it. The torque links start moving on their own. Bad from stock NWS harness. What a waste of time changing that was. So, another day later, she still sits. Gotta love it. I'm glad I'm off the next few days. Hopefully it will be gone by the time I get back to work. Wink
 
Arrow
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RE: CRJ-200 NWS Problem

Tue Apr 10, 2007 2:27 am

Check the political credentials of your pilots. Are they all Republicans?  Smile
Never let the facts get in the way of a good story.
 
UAL Bagsmasher
Topic Author
Posts: 1839
Joined: Wed Sep 08, 1999 12:52 pm

RE: CRJ-200 NWS Problem

Tue Apr 10, 2007 3:05 am

LOL...Good in theory, but I drove it around the airport myself, and it pulled me to the right too Wink
 
RJwrench85
Posts: 117
Joined: Sat Sep 16, 2006 6:36 am

RE: CRJ-200 NWS Problem

Wed Apr 11, 2007 1:12 pm

Did you guys run through SL RJ-SL-32-039
ATA: 3250
DATE: 25 Aug 03
SUBJECT: Lateral Deviation Customer Questionnaire
MODEL: CL-600-2B19
APPLICABILITY: ALL CRJ100/200/440
PURPOSE:
In order to gather data to address the concerns raised in references with the above subject
Bombardier Aerospace In-Service Engineering needs more specific information from the
operators experiencing occurrences related to erratic directional control experienced during
ground maneuvers.


Edited to correct SL #

[Edited 2007-04-11 06:15:54]
"Improvise, Adapt, Overcome"
 
aogdesk
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RE: CRJ-200 NWS Problem

Wed Apr 11, 2007 11:25 pm

Bagsmasher, do you know how many days or hours were spent doing all the troubleshooting before Bombardier suggested focusing on that wiring harness? I can't believe how far some issues go before someone pops up and says "Oh, we've seen that exact problem before".
 
miamiair
Posts: 4249
Joined: Thu Jul 15, 2004 9:42 pm

RE: CRJ-200 NWS Problem

Thu Apr 12, 2007 12:29 am

What about the trunnion/attach point being off the centerline?

Doesn't take much, but then again I am familiar with Boeing/MD products.
Molon Labe - Proud member of SMASH
 
UAL Bagsmasher
Topic Author
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Joined: Wed Sep 08, 1999 12:52 pm

RE: CRJ-200 NWS Problem

Thu Apr 12, 2007 6:40 am

Well, the verdict is in. They changed the NWS harness a second time with a GOOD part from stock, and she finally flew the coup. Good bye and good riddance:P
 
CF188A
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RE: CRJ-200 NWS Problem

Thu Apr 12, 2007 11:22 am

pray to God that the wind shifts  Wink
Dream as if you'll live forever. Live as if you'll die tomorrow~ RIP ... LJFM

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