15.19 Flashcards
What is the name of the fairing the engine is housed in?
Nacelle
What type of aerodynamic smoothness must parts of the engine cowling have?
Class 1, maximum smoothness
What is the other class of smoothness required on some parts of the engine cowling?
Class 2
What does the acoustic lining do on engine cowlings?
Helps reduce noise
What are the two angles you can latch a cowling open at?
40 or 55 degrees
What does the fan reverse cowling do to airflow?
Directs it in the opposite direction
Is the fan reverse cowling heavy or light?
Heavy
What is the reverse cowling opened with assistance of?
Hydraulic pressure from hand pump
What problems so reverse cowlings face with aerodynamics when shut?
They don’t line up and put high loads on engine inlet.
What does high aerodynamic load on a cowling and deformation cause?
Tip rub with uneven clearances on both sides
How to you prevent aerodynamic problems with the reverse cowling?
Use a stiff case
What fire protection does the fan thrust reverse cowling have?
Fire protective coating, fire seal
What engine section does the core cowling cover?
Hot section
With acoustic panels what materials are used in low and high temperature areas?
Composites in low temp areas and fibrous metallics in high temp areas
How is the pressure relief valve held in the closed position?
By a spring
What are the names of the two mounts that connect the engine to the wing?
Aft and fwd mount
What engine mount is engine thrust transferred through?
Fwd mount
What do the engine attachment bolts carry? Load wise
All vertical loads
Is the forward engine mount fail safe?
Yes
What loads does the aft mount transfer?
Vertical and side loads
How is the engine secured to the aircraft upper nacelle?
Resilient rubber mounts and links, and reduce vibration
If there is pitting or cracking in the mount what happens?
Has to be replaced
Connectors on modern aircraft have how many threads?
3 separate threads
What are the 3 methods for lifting an engine?
Bootstrap, overhead crane, uplift loader
