40 Questions
What is the likely cause of increasing RGB oil pressure?
Debris lodged in the oil galleries
Where does the oil mist come from to lubricate the accessory drive train?
Main scavenge pump
How is the RGB scavenge system divided?
By a bearing diaphragm
What are the two pumps used to effectively scavenge the RGB?
Nose scavenge pump and main scavenge pump
At what pressure does the system pressure relief valve begin to open?
250 PSI
What is the purpose of the check valve in the RGB oil system?
Prevent oil tank drainage into the RGB during engine shutdown
How is the oil returned to the accessory gearbox after being removed by the breather?
Through the uppermost vertical strut of the air inlet housing
In what scenario would the filter bypass in the RGB pump and filter assembly open?
When filter outlet pressure reaches 300 PSI
What ensures that oil does not drain into the RGB from the oil tank when the engine is not running?
The check valve in the filter assembly
How is the RGB (Reduction Gearbox Assembly) pump pressure typically regulated?
By restrictions in the oil galleries within the RGB
What is the function of the nose scavenge pump?
Scavenges oil from the propeller shaft bearings
Where is the main scavenge pump located?
Inside the reduction gear assembly
What does the pressure relief valve in the scavenge system do?
Relieves pressure at 250 PSI
When is the nose scavenge pump particularly active in scavenging oil?
When the aircraft is in a nose down attitude
Where does the scavenged oil from the power section and RGB systems pass before combining?
Magnetic chip detectors
What is the purpose of the external scavenge oil filter in the RGB and power section?
To prevent contamination of the power section oil system components.
What is the function of the bypass valve in the external scavenge oil filter?
Operates when the filter becomes blocked to allow oil flow.
How does the fuel cooled oil cooler contribute to preventing ice crystals from entering the fuel system components?
By providing a means to transfer waste heat from scavenged oil to incoming fuel.
What is the range within which the bypass valve in the external scavenge oil filter operates?
30 PSID and 50 PSID
Why is an air cooled oil cooler used after the fuel cooled oil cooler in the oil return path?
To cool down the scavenged oil before it enters the oil tank.
What is the main function of a cyclonic breather?
Create a cyclonic flow pattern to separate oil from air
How does a cyclonic breather separate oil from air?
By creating a swirling flow pattern
What is the role of a temperature transmitter in an oil system?
Sense oil temperature and transmit a signal
Which component accurately senses oil temperature?
Temperature transmitter
What happens to oil in a cyclonic breather after separation from air?
It settles at the bottom of the separator cylinder for drainage
What is the purpose of the delivery element in the power section oil pump?
To pump oil through passages in the accessory gearbox
What is the function of the bypass valve in the oil system?
To allow oil to bypass the filter if it becomes blocked
When does the check valve open in the system?
Within the range of 6–10 PSI
Which component prevents excessive back-pressure at the power section oil pump outlet?
Bypass valve
Where does the oil enter after passing through the filter assembly in the oil flow path?
Annular ring formed by the air inlet housing and the compressor extension shaft housing
What is the purpose of a system pressure relief valve in an aircraft engine?
To prevent excessive pressure build-up in the lubrication system
How does a direct lubrication oil jet system differ from a mist and vapour lubrication oil jet system?
The mist and vapour system covers a wider lubrication area compared to the direct system
What is the main function of breathers in an engine's oil scavenge system?
To prevent excess air pressure build-up in the oil scavenge system
In what way does an under race lubrication jet system improve cooling?
By routing oil through rotor shafts and bearing journals before reaching the bearings
What role do compressor bleed air play in some engines' lubrication systems?
Delivering a mist and vapour lubrication oil spray through a mist and vapour lubrication oil jet
How are slot acting oil jets utilized in bearing inner races different from conventional spray jet lubrication?
They provide a mist and vapour lubrication instead of direct spraying
Why is a wider area of lubrication preferred in some large engines?
To enhance cooling efficiency during high mechanical loads
What could be a consequence of an undesirable build-up of air pressure in an engine's oil scavenge system?
Insufficient lubrication of moving parts, causing premature wear
What is the primary benefit of using compressor bleed air for some engines' lubrication systems?
To deliver air/oil mist spray for wider area lubrication
What differentiates a direct lubrication oil jet system from an under race lubrication jet system?
The under race system routes oil through rotor shafts before reaching bearings
Learn about increasing RGB oil pressure, likely causes, and the system pressure relief valve's function in maintaining oil pressure. Understand how the system pressure relief valve operates to prevent damage due to excessive oil pressure.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
