Important maintenance tips for Global 7500 galley appliances

Effectivity: Global 7500 series aircraft

ATA: 25

By: Frédéric Charlebois—Technical Services

Bombardier reminds operators that appliances installed on Global 7500 series aircraft may require more frequent periodic maintenance.

Please pay attention to the maintenance schedule items covered in the Component Maintenance Manual (CMM) and the user guide for each appliance. In some cases, more frequent maintenance intervals may be required, even if appliances are mentioned in the Supplemental Maintenance Manual (SAMP) or Supplemental Time Limit Maintenance Check (STLMC).

This will prevent the unnecessary removal of appliances following a failure caused by clogged components. Flushing or decalcifying the coffee brewer or cleaning the air-chiller air filter are good examples of appliances requiring more frequent maintenance.

For the coffee maker and espresso maker, it is important to descale the unit regularly (every month as described in CMM 25-31-01 and 25-31-04.  

The use of hard water (mineral water or spring water) will leave scale deposits which slowly clog the system. The water hardness degree, mostly expressed as milligrams of calcium per liter (mg/l or PPM) as outlined in the table below, will influence the descale frequency and will affect accuracy of the water level sensor.  

The use of water high in calcium and magnesium salts is responsible for scale deposits, water level sensor misreads and many unscheduled component removals. Water high in calcium and magnesium salts is not recommended.  

Hardness levels in common brands of bottled water: 

A note on TDS labels: Is 1 mg/L equal to 1 ppm?

The short answer is yes. For water, 1 ppm = approximately 1 mg/L (also written as mg/l) of contaminant in water, and 1 ppb = 1 ug/L (also written as ug/l). A measurement of 6 mg/L is the same as 6 ppm.