NATOPS Chapter 2 Engine Oil, Start, Parameter sensing HSM-50 Flashcards
The engine oil system is
Self-contained, pressurized, recirculating dry sump system
A malfunctioning starter may be overridden by _____________
Manually holding in the starter until NG reaches 52 to 65% NG
Two ways to get pneumatic power for engine starts
APU
Engine crossbleed
What are the 3 ways to anti-ice the engine?
1) vent bleed air into the engine swirl vanes and inlet guide vanes by the ENG ANTI-ICE/START BLEED VALVE.
2) vent bleed air into the airframe engine inlet by the ENGINE INLET ANTI - ICE VALVE
3) Continuously pump engine oil through the SCROLL VANES
ENGINE ANTI-ICE/START BLEED VALVE uses what type of air?
5th stage bleed air
ENGINE ANTI ICE START BLEED VALVE malfunction is indicated by:
- Appearance or disappearance of ENG ANTI ICE ON advisory outside of specified range (somewhere between 80.5 and 96.5 deg is the transition range. Off above this range, on below this range) (at OAT of 20C, transition range is 85.5 to 90.5)
- NO illumination when the switch is ON.
- NO rise in TGT when switch is on.
With Eng anti ice on max TQ is reduced by
18%
INLET ANTI-ICE operates as follows:
Less than 4 OAT, the valve is open and the advisory comes on when inlet temp hits 93 C.
Between 4 and 13 OAT, The valve is controlled buy by a Freon Bellows begins closing at 4° and is completely closed at 13.
Above 13 OAT the valve is closed.
The two NP sensors send information to?
- The left sensor provides an Np signal to the DECU and the VIDS
- The right sensor feeds the torque computation circuit and the Np overspeed protection system
NG is sensed by?
The alternator sending a signal to the vertical instruments
TGT sensing
Thermocouple harness of 7 thermo couples that are averaged together and sent to the vertical instruments.
If DECU is not powered by either the ALTERNATOR or the backup 400 hz through ENG OVSP circuit the DECU will_______.
Indicate 71° higher than expected
How many main sump bearings are there in the Oil system?
6
How does the engine provide redundancy if a malfunction or damage totally interrupts the normal supply of oil?
The engine has 2 sets of oil jets to provide each main bearing with oil
What causes the #1/#2 OIL FLTR BYPASS caution to illuminate?
The oil filter bypass sensor switch
When does the thermal lockout for the oil PDI work?
What is it for?
below 38 C
to prevent the pdi from popping during cold-weather starts
How is oil cooled?
The fuel/oil cooler and the air/oil cooler (Scroll vanes)
Does the Engine Chip Detector have a burnoff feature?
no
What does the APU provide during engine start?
bleed air and electrical power
What position does the AIR SOURCE ECS/START switch need to be in for the APU to provide pneumatic power?
Doesn’t matter, APU will provide pneumatic power regardless of the switch position
For a crossbleed start, what must Ng be for the receiving engine?
What does this require the donor engine Ng to be?
Shall be a minimum of 24%
90-94%
With a faulty engine inlet anti-ice modulating valve, you could lose ___ power.
49%
When DE-ICE MASTER switch is on, and Ice is detected, what turns on?
- ENG ANTI-ICE
- WINDSHIELD ANTI-ICE
- BLADE DEICE POWER
How is Np sensed?
The power turbine has 2 sets of teeth that induce electrical pulses in the Np sensors. These teeth permit measurement of the torsion or twist of the shaft which is proportional to torque output