15.21 Operation And Monitoring Flashcards
When doing a ground run up what should be done
Positioned into wind, chocks, brakes applied
What should be checked to ensure an aircraft can have a test run
Tech log
Who should be informed prior to engine test runs
ATC
What should be positioned in an engine test run
A fire extinguisher (CO2) or a fire tender
What should be used as a datum during an engine run up
The oldest engine
What are the three groups of engine monitoring indications
-performance monitoring
-system monitoring
-condition monitoring
What is measured in performance monitoring
-EPR
-N1
-N2
-Fuel flow
-Exhaust gas temperature
How is EPR measured
Ratio of the jet pipe pressure to the compressor inlet. Gives ratio which is an indication of thrust
How do centrifugal compressor engines measure thrust
Measure relationship between engine Rpm And jet pipe temp
What can’t axial compressors measure the same parameters as a centrifugal compressor engine
Because engine RPM and thrust have no direct relationship
What is measured to indicate power developed on turbo shaft and turbo prop
torque monitoring systems
What is engine torque proportional to
Horsepower
What are the two types of sensing used on turboprop and turbo shaft engines
Hydro-mechanical and electronic
What can accumulation of contaminants on the compressor and turbine section do?
Seriously affect the engines performance
What are the containments on the compressor and what do they do?
The containments on the compressor are mostly salts and pollution and reduces the aerodynamic efficiency of the blade
In the turbine, the contamination takes the form of sulfidation, what does a build up of this cause?
A build-up of sulphur deposits from the burning fuel which destroys the aerodynamic shape of the turbine blades and the nozzle guide vanes. Over time, it will erode their surface finish (hot corrosion)
How do you clean salt out from the engines?
If the major cause of contamination is salt ingestion, a scheduled rinsing of the compressor with fresh water can avoid the harsher chemical treatment which otherwise will be required
How can you carry out this cleaning of salt?
This can be carried out either while motoring the engine over on the starter, or while running the engine at idle speed
What is this cleaning procedure known as?
It is known as desalination wash
What should all engine cleaning be done in accordance with?
Engine manufacturers instructions
What should you use in cold conditions if you need to flush the engine?
Only isopropyl alcohol is used
What is internal FOD?
Damage or hazards caused by foreign objects inside the aircraft
What is tool FOD?
Caused by tools left inside the aircraft following maintenance
What are some examples of FOD?
Aircraft parts, rocks, broken pavement, ramp equipment.
Parts from ground vehicles.
Rubbish left on the ramp and/or runway surfaces.
Ice on the wings, propellers, or engine intakes.
Bird strikes to the engines or other sensitive parts of the aircraft.
Dust or ash clogging the air intakes (sandstorms or volcanic ash).
Tools, bolts, metal shavings, lock wire, etc., left inside the aircraft or on the ramp floor following maintenance.
Why must all manufactured engines pass a stringent test and what is it?
Involves firing a frozen chicken into a running jet engine from a small cannon or simulate flying through a severe rainstorm this helps them know it will hold up fine
What happens if the bird causes a fan to detach?
If the bird strike causes an engine fan blade to detach, the engine fan case must be strong enough to contain the blade and prevent damage or loss of the aircraft
What did the early Boeing 737 have?
Gravel runway kit
What did the Boeing 737 gravel kit include
The aircraft was fitted with gravel deflectors on the landing gear and screens that prevented gravel from entering the open wheel wells when the gear was extended
What did the Boeing 737 gravel kit include
The aircraft was fitted with gravel deflectors on the landing gear and screens that prevented gravel from entering the open wheel wells when the gear was extended
