M15.10 Lubrication System

Oil pressure and scavenge pumps are usually:

• Diaphragm pumps

• Multi-plunger pumps

• Spur gear pumps

A spur gear type pump draws oil in and

• Carries it through the intermeshing gears

• Carries it around between the gear teeth and the casing

• Carries the volume around between the teeth and then pressurizes it in the mesh

The purpose of the pressure filter in a Lubrication System is to:

• Protect the oil jets

• Protect the pressure pump

• Protect the scavenge pumps

The 'Last Chance' thread filters in the oil distribution system are examined:

• During routine line maintenance

• During fault diagnosis

• During engine overhaul

The chip detectors are:

• Coarse wire mesh filters positioned in the scavenge return lines

• Magnetic plugs positioned in the scavenge return lines

• Perforated strainers in the oil tank

Turbine engine oil is normally cooled by:

• Ram air

• Fuel

• Bleed air

The oil system pressure relief valve is usually positioned

• Between the pressure pump and the pressure filter

• Between the pressure filter and the oil cooler

• Between the oil tank and the pressure pump

The oil scavenge pumps have a greater capacity than the pressure pump because

• The oil has to be forced back in to the tank

• The oil is hot

• The oil is hot and aerated

The air that accumulates in the oil tank is

• Dumped overboard through a gearbox driven centrifugal breather

• Passed back to the bearing chambers and dumped out through the air seals

• Dumped overboard through an open vent in the oil tank

The oil pressure in the cooler is

• same as the fuel pressure

• lower than the fuel pressure

• higher than the fuel pressure