Narrative:

Aircraft came to hangar for nose landing gear check. Myself and person #2 were assigned to accomplish this maintenance. Upon arrival; the nosewheel steering control cable was inspected and determined to be worn out of limits by quality assurance. The aircraft was then jacked and we started the nose landing gear check maintenance. I worked the nosewheel steering cable replacement and focused on the right&right of nose landing gear check components. We were at the point to cycle the nosewheel steering 25 cycles after double tension on nosewheel steering cable. We cycled the nosewheel steering approximately 3-4 times when we noticed that we had not disconnected the scissors links from each other. The aircraft was still jacked. We then lowered the aircraft all the way down and completed our 25 cycles. We then went to lunch. After lowering the aircraft; there was no leakage noted as we thought might happen with operating the nosewheel steering in the air. We also did not notice or hear any unusual sounds or unusual system operation when we operated nosewheel steering when we completed the 25 cycles on ground. After lunch; the aircraft was jacked again and I proceeded with the final rig on the nosewheel steering cables. The nosewheels appeared to be centered and the metering pin rig pin was a drop fit with 0 cable tension. The metering valve input rod end bolt was also drop fit. I rigged the nosewheel steering cables to the required tension per temperature and maintenance manual but could not get a drop fit on the bell crane in left upper nose wheel well when tension was dead-on each cable. I continued to rig the cables but could not get all rig pins to drop fit. At this time I was getting tired and sore due to the tight work area to rig/adjust cables and never experienced that much trouble rigging nosewheel steering cables before. Another co-worker came over to see how we were doing. We told him our situation with the rig and also wondered if operating the nosewheel steering in the air had something to do with our problem. With his experience; he said yes. He shook the nose gear at the tires and the nose gear found a new center off a few degrees. He also stated that we needed to do a strut repack as seals could be damaged or damage to centering cams. At this point it was also noted that fluid/foam was seeping out of one area of the nose gear lower gland nut thread area. At this point; we stopped the rig and started to disassemble the nose gear for a strut repack. The gland nut had no initial torque when we removed the lock and started to loosen it. After a few turns; it took a lot of torque all the way until the nut was removed. After the inter cylinder was removed; damage was noted on the lower bearing lock tabs which were worn on upper part of tabs. Damage was also noted on the nose gear outer cylinder where gland nut screws on. This damage was flaring. No noticeable damage was found on the upper or lower centering cams or keep shear pins. It was determined that a new strut assembly would be required. We then completed the necessary maintenance paperwork to document findings and open issues. After cleaning up the work area; we clocked out. At no time did we try to 'cover' this up as has been perceived. Yes we did not disconnect the scissors links and yes we did operate the nosewheel steering with aircraft in air. I take full responsibility for my actions or lack of; but it was not intentional. Out of all the nose landing gear checks I've done; I'm not sure why it happened -- we always disconnected the links. As I have never experienced what can happen with operating the nosewheel steering in the air; I 'assumed' there would be heavy/moderate leakage from seals and/or experience some noise or abnormal operation. As stated; none of this occurred until seepage was noted at the gland nut thread later on in the morning. As I take full responsibility for my actions; I do not have the experience or knowledge enough to fully know to what full ex

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Original NASA ASRS Text

Title: Two Mechanics report on the problems encountered during a nose landing gear (NLG) check; when they failed to disconnect the steering links (scissors links) on a B737-300.

Narrative: Aircraft came to hangar for nose landing gear check. Myself and Person #2 were assigned to accomplish this maintenance. Upon arrival; the nosewheel steering control cable was inspected and determined to be worn out of limits by Quality Assurance. The aircraft was then jacked and we started the Nose Landing Gear check maintenance. I worked the nosewheel steering cable replacement and focused on the R&R of nose landing gear check components. We were at the point to cycle the nosewheel steering 25 cycles after double tension on nosewheel steering cable. We cycled the nosewheel steering approximately 3-4 times when we noticed that we had not disconnected the scissors links from each other. The aircraft was still jacked. We then lowered the aircraft all the way down and completed our 25 cycles. We then went to lunch. After lowering the aircraft; there was no leakage noted as we thought might happen with operating the nosewheel steering in the air. We also did not notice or hear any unusual sounds or unusual system operation when we operated nosewheel steering when we completed the 25 cycles on ground. After lunch; the aircraft was jacked again and I proceeded with the final rig on the nosewheel steering cables. The nosewheels appeared to be centered and the metering pin rig pin was a drop fit with 0 cable tension. The metering valve input rod end bolt was also drop fit. I rigged the nosewheel steering cables to the required tension per temperature and Maintenance Manual but could not get a drop fit on the bell crane in left upper nose wheel well when tension was dead-on each cable. I continued to rig the cables but could not get all rig pins to drop fit. At this time I was getting tired and sore due to the tight work area to rig/adjust cables and never experienced that much trouble rigging nosewheel steering cables before. Another co-worker came over to see how we were doing. We told him our situation with the rig and also wondered if operating the nosewheel steering in the air had something to do with our problem. With his experience; he said yes. He shook the nose gear at the tires and the nose gear found a new center off a few degrees. He also stated that we needed to do a strut repack as seals could be damaged or damage to centering cams. At this point it was also noted that fluid/foam was seeping out of one area of the nose gear lower gland nut thread area. At this point; we stopped the rig and started to disassemble the nose gear for a strut repack. The gland nut had no initial torque when we removed the lock and started to loosen it. After a few turns; it took a lot of torque all the way until the nut was removed. After the inter cylinder was removed; damage was noted on the lower bearing lock tabs which were worn on upper part of tabs. Damage was also noted on the nose gear outer cylinder where gland nut screws on. This damage was flaring. No noticeable damage was found on the upper or lower centering cams or keep shear pins. It was determined that a new strut assembly would be required. We then completed the necessary maintenance paperwork to document findings and open issues. After cleaning up the work area; we clocked out. At no time did we try to 'cover' this up as has been perceived. Yes we did not disconnect the scissors links and yes we did operate the nosewheel steering with aircraft in air. I take full responsibility for my actions or lack of; but it was not intentional. Out of all the nose landing gear checks I've done; I'm not sure why it happened -- we always disconnected the links. As I have never experienced what can happen with operating the nosewheel steering in the air; I 'assumed' there would be heavy/moderate leakage from seals and/or experience some noise or abnormal operation. As stated; none of this occurred until seepage was noted at the gland nut thread later on in the morning. As I take full responsibility for my actions; I do not have the experience or knowledge enough to fully know to what full ex

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.