14. Propulsion - Q&A
25 questions found
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A compressor shaft rotates on
- sintered bearings
- ball and roller bearings
- plain bearings
What about Needle Roller bearings, those are not balls?
Ratiometer pointer movement is achieved by
- one coil providing a torque against a permanent magnet
- two opposing coils providing a torque in a varying magnetic field
- two opposing coils providing a torque in a permanent magnetic field
Do this means ratiometer in permanent magnetic field as in DC?
If AC ratiometer will be in a varying magnetic field?
What is the pressure increase over one stage of a centrifugal compressor?
- 5:1
- 1.2:1
- 8:1
i think the answer should be 8:1
In a FADEC system, active control switchover occurs
- on shutdown.
- when channels A and B are healthy.
- on engine startup only.
I think the correct answer is ON SHUTDOWN.
I found the below explanation from a different site.
On the CF6 FADEC, each startup uses an alternative channel.But the switch-over occurs on shutdown of the previous run.The reason for this is that the switch-over at start up might interrupt the start-up sequence.
What is the pressure increase over one stage of a centrifugal compressor?
- 5:1
- 1.2:1
- 8:1
I think the answer is 8:1 because Jeppesen Gas Turbine Powerplant quotes the latest modern centrifugal compressor as having a pressure ratio of 10:1
A fuel flow transmitter requires a motor or a synchronous motor to have a
- constant voltage within small tolerances
- constant frequency within small tolerances
- low EMF as it is immersed in fuel
Can someone please explain.
An increase in fuel flow through the impeller type fuel flow transmitter is measured by
- drum lags impeller
- impeller lags turbine
- decreasing angle between the two
Can someone please explain.
An aircraft flying at 800mph would typically use
- turbojet
- turbofan
- turboprop
it could be turbofan too
A thermocouple indication is taken from the
- hot junction
- cold junction
- difference between the hot junction and the cold junction
Cant understand this answer, it is suppose to be difference b/w hot and cold.please explain why only cold junction.
An EPR system reads slightly over 1, this would mean
- the transmitter datum point has moved and needs replacing
- no action required this is normal
- the indicator needs re-calibrating back to 1
EPR should read 1, is there any tolerance in EPR ????????
Propeller torque is analogous to
- engine RPM
- shaft horsepower
- propeller RPM
not much collection of questions in this module....???/
The variable bleed valves on a engine at start up is
- open
- closed
- modulating
bleed valve of the engine remain open during the starting of the engine???????????????????
The fuel metering unit has direct inputs via
- only the EEC
- the EEC and the fire control handle
- the EEC, fire control handle and the engine master switch
EEC directly controls FMV, fire handle and master s/w is directly connected to SOV.
When using a test set to test an EGT thermocouple circuit
- no compensation for ambient temperature is required
- only consider ambient temperature compensation if the ambient temperature is over 20oC
- always compensate for ambient temperature
WRONG AGAIN!!!!
EPR is a ratio of
- P1 to P4
- P1 to Pfan
- P1 to P6
WRONG ANSWER!!!!!!
in a flow type fuel system, fuel shutoff is done by
- mechanical ball valve
- fcu torque motor
- l.p fuel cock
Help..need some reference!!
How is fuel flow varied in a variable displacement pressure type pump?
- Alter the camplate angle
- Remote servo pressure
- Direct cable to camplate
how many types of pumps are there? and what about camplate angle?
A short circuit in a d.c ratiometer will give
- max scale reading
- zero scale reading
- min scale reading
how??
Propeller speed is measured from
- a slip ring pulse probe
- a tachometer on the LP turbine shaft
- a pulse probe at the engine side of the reduction gear
can somebody give me a reference with explanation plz.
How are the combustion chambers cooled?
- By l.p compressor air
- By h.p compressor air
- By fan pressure air
how??
Oil systems consists of
- 2 systems
- 3 systems
- 4 systems
Dose 3 system mean to be 'wet sump','dry sump' & 'full flow', then what about, 'pressure relief valve' & ' total loss system' please give some reference authentic enough to justify your answer. :)
The inlet of a turbo fan is
- divergent
- convergent
- convergent-divergent
How come?
Manifold pressure is measured
- at inlet port above and below ambient conditions
- at inlet port above and below standard atmosphere at sea level
- at inlet port indicating boost pressure
at inlet port above and below standard atmosphere at sea level....
If a manifold pressure gauge is measuring in a supercharged engine it will measure above 29.92 in Hg.If the supercharge is not use it will measure below that figure. EHJ Pallett Integrated Instruments Page-355
When using a test set to test an EGT thermocouple circuit
- no compensation for ambient temperature is required
- only consider ambient temperature compensation if the ambient temperature is over 20oC
- always compensate for ambient temperature
Always compensate for ambient temperature....
To test the system the test set has to be trimmed for ambient temperature,as the system when in operation is adjusted for ambient temperature by the compensating resistor.This is stated in B 737 AMM.
The inlet of a turbo fan is
- divergent
- convergent
- convergent-divergent
the area of turbofan engine is like a convergent type na?
more area in intake and decreasing the area while going inside na??
please clarify me