Jeppesen Oral- Chapter 11 (Aircraft Instrument Systems ) Flashcards
(46 cards)
What instruments in an aircraft are connected to the static system?
instruments in an aircraft are connected to the static system?
The airspeed indicator, the vertical speed indicator, and the altimeter
What types of repairs or alterations can a certificated A&P mechanic make to aircraft instruments
None. All repairs and alterations must be made by the instrument manufacturer or by an FAA-approved repair station certificated for the particular instrumen
WHat is the significance of a red radial line on the dial of an aircraft instrument?
A red radial line marks a never-exceed conditon.
What is the significance of a yellow arc on the dial of an aircraft instrument?
A yellow arc marks a caution range of operation.
What is the significance of a green arc on the dial of an airspeed indicator?
A green arc indicates the normal range of operation.
What is the significance of a white arc on the dial of an airspeed indicator?
A white arc on an airspeed indicator indicates the airspeed at which the flaps may be lowered.
What is used to warn a mechanic that the glass on an aircraft instrument that contains the range marks has slipped?
A white slippage mark that extends across the lower part of the instrument conver glass and the instrument case bezel shows whether or not the glass has slipped. A slipped glass would put the range marks over the incorrect numbers.
Where can a mechanic find the range markings that are required on the instruments in a particular aircraft?
In the Type Certificate Data Sheets for the aircraft
What check must be made if a mechanic replaces any instrument that is connected to the instrument static system?
The static system must be checked for leaks.
Why are many of the electrical systems mounted in steel cases?
A steel case concentrates the flux produced by magnets in the instrument and keeps it from affecting other nearby instruments.
Why must an aircraft instrument panel be electrically bonded to the primary aircraft structure?
The bonding straps carry the return current from the instruments into the aircraft structure.
What error is corrected when an aircraft compass is swung?
deviation error
What fluid is used in an aircraft magnetic compass?
A special water-clear fluid that is similar to kerosene.
What is the maximum amount of deviation error that is allowed when a magnetic compass is installed in an aircraft?
10 degrees
What is the maximum amount of leakage that is allowed when checking the static system of an aircraft that is operated under Instrument Flight Rules?
For an unpressurized aircraft, the system is checked with a 1,000-foot indication on the altimeter. It must not leak more than 100 feet in one minute. For a pressurized aircraft, the system is checked at the maximum certificated pressure differential of the cabin. It must not leak, in one minute, more than 2% of the equivalent altitude of the maximum differential pressure or 100 feet,whichever is greater.
Why must the length of the thermocouple leads not be altered when installing a cylinder head temperature indicator?
An instrument operated by a thermocouple is a current-measuring device. The resistance of the thermocouple and its leads must be kept at the value specified for the indicator.
What should a manifold pressure gauge read when the engine is not operating?
It should read the existing barometric pressure.
What is the difference between a two-minute and a four-minute turn and slip indicator?
A two-minute turn indicator gives a one-needle-width deflection for a standard rate of turn (three degrees per second). A four-minute turn indicator gives a one-needle-width deflection for a half-standard rate of turn (1-1/2 degrees per second). A four-minute turn indicator has doghouse shaped marks located two needle widths away from the center mark. When the needle is lined up with a doghouse, the aircraft is making a standard rate turn.
What is the difference between a turn and slip indicator and a turn coordinator?
A turn and slip indicator is sensitive about only the yaw (vertical) axis of the aircraft. A turn coordinator uses a canted gyro which makes it sensitive about both the roll and yaw axes.
What is used as the sensor in the fuel tank for an electric-type fuel quantity indicating system?
Tubular capacitors which extend across the fuel tank from top to bottom.
Why is a dual tachometer used on a single-engine helicopter?
One needle indicates the speed of the engine, and the other indicates the speed of the main rotor. When the needles are married, the clutch is not slipping and the rotor is solidly engaged to the engine.
In what units is the tachometer used on a turbine engine calibrated.
In percentage of the takeoff RPM
What kind of system is used to measure the exhaust gas temperature of a turbine engine?
An averaging system made up of a series of thermocouples arranged around the inside duct of the engine.
What would likely cause the needle of an electrical oil temperature gauge to peg on the high side of the instrument dial?
There is probably an open in the bulb circuit that is causing the instrument to see an infinite resistance. The higher the resistance of the bulb circuit, the further the needle moves across the dial.
