Commercial Fixed Wing
Maintenance Powerplant; Maintenance Airframe
Workload; Time Pressure; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Object
Aircraft Aircraft Damaged; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; Environment - Non Weather Related; Equipment / Tooling; Human Factors; Procedure
Aircraft X required a weight on wheels 'H' check of the NLG (Nose Landing Gear) and right MLG (Main Landing Gear). We centered the ladder in between the NLG doors and I began to install the pressure gauge to the top fitting on the NLG strut. While doing so the ladder must have shifted positions. During this time I never heard any loud hissing to indicate to me that air was being released due to extreme noise from our A/C and other A/C & vehicles in the vicinity. My partner went up to turn off the A/C power due to the noise level. A few minutes after coming down from the ladder I noticed the left NLG door sitting on top of the ladder. I immediately moved the ladder to prevent any further damage. I suspect that air escaped from the t-handle on top of the tooling and due to the noise I wasn't able to hear it. The very slow release of air may have caused us to not notice the plane had shifted.
Aircraft X required a weight on wheels (H) check of the nose and right landing gear struts. We centered a work ladder at the nose landing gear to have clearance for aircraft movement. My work partner attached the tooling pressure gauge to the fitting on top of the strut. I went up inside the aircraft to remove ground power because of the noise and communication issues we were having. After going down the jetway and returning to the work area I noticed that the left nose gear door had settled on the work ladder. The ladder must have been accidentally shifted just enough to have clearance issues with the aircraft and some type of unintended slow pressure release of the company tooling pressure gauge. No one could hear the strut nitrogen leaking because of the flight line noise and slow nature of the depressurize.
Technicians reported aircraft settled on Nose Landing Gear Door during a Strut Height Check.