12.40.8(a) . explain the basic principle of a rate gyroscope;
Turn Indicator
– indication is by deflection of the needle – towards direction of turn
– indicates rate of turn
Turn Co-ordinator
– indication is by the tilting of the aircraft symbol – towards direction of turn
– indicates rate of turn
– indicates roll rate
– dies not indicate pitch even though looks like artifical horizon
12.40.8. With respect to the turn indicator/coordinator:
12.40.6(b) . precession.
All rotating masses possess the two characteristics :-
Rigidity
– or gyroscopic inertia – come from the high mass and high speed of rotation of the instrument
– helps them maintain their alignment in space
Precession
– when a side force is applied at some point around the rim of a spinning gyro rotor, it will tilt the rotor as if the force wasw applied at 90 degrees further on in the directin of rotation
12.40.6(a) . rigidity;
All rotating masses possess the two characteristics :-
Rigidity
– or gyroscopic inertia – come from the high mass and high speed of rotation of the instrument
– helps them maintain their alignment in space
Precession
– when a side force is applied at some point around the rim of a spinning gyro rotor, it will tilt the rotor as if the force wasw applied at 90 degrees further on in the directin of rotation
12.40.6. Describe the gyroscopic properties of:
12.40.4. State the likely effects of reduced or nil suction in the vacuum system.
12.40.2. Outline the basic principle of operation of the vacuum system.
The rotors of the gyroscopes in aircraft insturments are driven by air passing through a vacuum system or elecrically
Main component is the engine-driven vacuum pump that sucks air from within the cases of the gyroscopic instruments
Replacement air is drawn through a fine mesh filter and the enters the cases of the instruments through nozzles which direct a high speed flow of air at the grooves cut into the periphery of the gyro rotators
If suctin drops below 4.5Hg the the gyro speed will be reduced and the instruments can slow down become sluggish and behave erratically or stop functioning
12.38. Magnetic Instruments
12.38.10. State the compass pre-flight serviceability checks, and the precautions whencarrying magnetic items in an aircraft. Sub Topic Syllabus Item
Check the compass is securely installed and can be easily read
Check the liquid is free of bubbles and is not discoloured
Check the glass is not broken, cracked or discoloured
Check compass is horizontal in its mounting
Check location of the compass deviatoin card in the cockpit
Check that compass indication is apporximately correct – with the alignment of the runway and that when taxiing out turn aircraft to L and R to check operation of the turn co-ordinator
If carrying electrical or metal goods check they are located as far away as possible from the compass
12.38.8(b) . turning error.
In a turn the plane of rotation of the magnet system and compass card become tilted with respect to the horizontal
When the aircraft turns through N or S headings a component of dip now acts in the plane of rotation
This causes the compass to turn away from its proper orientation
When turning through E or W dip acts directly toward or away from the pivot and there is no turning effect on the system
In medium bank turns turning error is significant – of the order of 30 degrees