Date: 201809
Aircraft: B737 Next Generation Undifferentiated
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Parked
Aircraft component: Nose Gear Wheel
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Communication Breakdown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Pre-flight
Result: General Maintenance Action
Contributing factors: Procedure; Human Factors; Company Policy; Aircraft
Primary problem: Procedure

Narrative: Aircraft X came to the gate with an open log write up that read: NOSE WHEEL VIBRATES AT TAKE OFF MX (maintenance) CHECKED THE NOSE TIRES FOR US. RUMBLE DURING TAXI. VIBRATION ABOVE 120 KT ON TAKEOFFAfter following FIM (Fault Isolation Manual) task 32-51-00-810-804 it was determined that with the lack of history and the condition of the tires that that both NLG (Nose Landing Gear) tires would require replacement on the gate. In order to ensure the safety of the aircraft; maintenance and ground personnel the first item in the flight deck is the maintenance safety [tag]. The page prominently displayed on the center pedestal read as follows: AC MX work in progress WARNING: DO NOT TOUCH OR OPERATE ANY SWITCH OR CONTROL WITHOUT FIRST CHECKING WITH THE AIRCRAFT LEAD OR SUPERVISOR!AT THIS TIME the Aircraft had a BROKEN MRD (Maintenance Release Document). The aircraft was not released from maintenance. Maintenance personnel were preparing the aircraft for a dual NLG tire change IAW (In Accordance With) AMM (Aircraft Maintenance Manual) 32-45-21-400-801. 3 each Downlock devices where installed IAW GMM (General Maintenance Manual). [Work orders] were generated to document the replacement of the NLG tires. While beginning the jack the nose of the aircraft the flight crew entered the flight compartment; and began to prepare the aircraft for a departure. The jacking of the NLG stopped and I returned the flight compartment to find the First Officer inputting his flight plan and beginning his pre-departure check. The maintenance safety [manual] was still displayed on the center pedestal. I then asked the crew what was going on and why they by-passed the maintenance [manual] and they stated that they are allowed to still use the aircraft MCDU (Mulitpurpose Control Display Unit). At that point I asked the Captain and First Officer to leave the flight deck because of the NLG tire changes and that for my safety they are not to press ANY switch or button. The Captain insisted that they are allowed. I returned downstairs and a coworker also working the NLG tire change then went upstairs and asked them to completely leave the aircraft for our safety and the Captain said he would make a PA announcement and everyone would leave.We continued working when the Captain came down to the ramp area where we were working and began asking what is the correlation between the MCDU and the AC nose tires. I then explained it does not matter and that no button or switch should be pushed and that it is endangering the aircraft and the ground personnel that if hydraulics were to come on or the tiller moved the AC could come off the nose jack. By BYPASSING the maintenance safety [manual] the Captain and the First Officer put not only the AC in immediate danger but all maintenance personnel and ground personnel in the area in danger. The Captain's complete arrogance and anger towards the fact that he was not allowed in the flight compartment angered him to the point of swearing at me and my co-workers. At this point I radioed to my direct supervisor. The Captain returned upstairs. And the Tech Operations maintenance supervisor conferenced with the Captain and returned to speak with us saying that he was not sure of the rules and that if the [manual] does indeed mean the NO SWITCH can be pushed and that the MCDU is okay to be used. He then asked me [to] send him the reference material so that he can read it for himself because he was unsure. I then explained that he is the supervisor and HE should know the GMM and that it is unacceptable for the crew to do what they did. He said he took note of the Captains name so he could send him the appropriate GMM for the Captain to read because the Captain and the supervisor were unaware of the company policy related to Lock out tag out [per] GMM. The Captain made it clear to us that it was HIS aircraft and they will do as they wish and that we 'think' that they are stupid; this is clearly not the case that these procedures are there for everyone's safety. This showed a large lack of respect for maintenance personnel's safety. After the supervisor conference with the crew they returned to the flight deck with the [maintenance manual] in place and continued their pre-departure process.The crew seemed to be unaware of the magnitude and danger that was created in this event and did not take my warnings or upset seriously. This is the THIRD [report] I have filed regarding BYPASSING OF LOTO (Lock-Out Tag-Out) DEVICES AND THE MAINTENANCE [Manual] in THREE MONTHS. It seems that only aircraft damage or loss of life will bring this to the company's attention. The aircraft was later released without further incidence.




Synopsis: B737 Maintenance Technician reported that the flight crew ignored the safety requirement while maintenance was working on the aircraft.