<< >> NASA ASRS Report 1257463, April 2015

A lead aircraft maintenance technician (amt) reports about a potential fire hazard that could develop in the lower lobe forward cargo compartment outboard sidewall on md-11 aircraft. Reporter found a deferred potable water system pressurization air compressor pump and cannon plug very hot to touch during removal/replacement (right/right) of the deferred pump. MEL does not require a circuit breaker (C/B) pulled or cannon plug be disconnected for the deferral.

Attributes
ACN	1257463
Time
Date	201504
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Potable Water Storage control indication
Person 1
Function	Lead Technician
Qualification	Maintenance Airframe Maintenance Powerplant
Experience	Maintenance Lead Technician 2 Maintenance Technician 18
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

We had a potable water system pressurization air compressor on MEL. During removal/replacement (right/right); found [air] pump and cannon plug very hot to touch. MEL does not require a circuit breaker (C/B) to be pulled or the cannon plug to be removed. I think this creates a fire hazard. If pump is seized; as this one was; an overheat condition is possible. This is much more likely on the ground as the pump is only powered when the APU and engines are 'off'; but if the timing was right; a fire could start and remain undetected until after take off.

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Original NASA ASRS Text

Title: A Lead Aircraft Maintenance Technician (AMT) reports about a potential fire hazard that could develop in the Lower Lobe Forward Cargo compartment outboard sidewall on MD-11 aircraft. Reporter found a deferred Potable Water System Pressurization Air Compressor pump and Cannon plug very hot to touch during Removal/Replacement (R/R) of the deferred pump. MEL does not require a Circuit Breaker (C/B) pulled or Cannon plug be disconnected for the deferral.

Narrative: We had a Potable Water System Pressurization Air Compressor on MEL. During Removal/Replacement (R/R); found [Air] Pump and Cannon plug very hot to touch. MEL does not require a Circuit Breaker (C/B) to be pulled or the Cannon plug to be removed. I think this creates a fire hazard. If pump is seized; as this one was; an overheat condition is possible. This is much more likely on the ground as the pump is only powered when the APU and engines are 'Off'; but if the timing was right; a fire could start and remain undetected until after take off.

Data retrieved from NASA's ASRS site 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.