Seminole Systems

Question 1

Which engine?

Answer 1

reciprocating engine - converts chemical to mechanical energy
lycoming
direct drive
4 cylinder
horizontally opposed
propeller produces thrust
2700RPM at sea level 2 props
180 HP per engine
counterrotating (left clockwise, right counterclockwise)

Question 2

turbojet/turbofan vs reciprocate/turbopros

Answer 2

turbojet/fans increase air velocity thru engine increases thrust

Question 3

abnormal combustion definition and causes

Answer 3

• uncontrolled explsoive ignition of fuel-air mixture within combustion chamber
• can lead to piston, cylinder or valve failure if not corrected
• engine overheating, roughness, loss of power

causes:
- burning lower fuel grade
- high manifold pressures with low rpm
- high power setting, lean mixture
- extended ground operations
- steep climbs

Question 4

whats preignition

Answer 4

fuel-air mixture ignites before normal igntion, caused by residual hot spot (small carbon deposit, cracked spark plu insulator; other damage inside cylinder) in combistion chamber

Question 5

fine vs coarse vs feathering

Answer 5

more oil pressure as prop going fwd, higher RPM

fine pitch - climb
coarse - cruise
feathering - least drag

Question 6

what is the counterweight, spinner dome, low pitch stop in the nose

Question 7

prop governor functions (2) and how

Answer 7

regulates oil into and out of prop
- change prop blade angle
- maintain constant RPM as air load on the properller changes

speeder spring, pilot valve, fly weight

Question 8

Propellor pitch is affected by five factors for high/low pitch

low pitch - take off and clilmb

Answer 8

high pitch/low rpm:
nitrogen gas
feathering spring
counterweights

low pitch/high rpm:
oil pressure
propellor blade aerodynamic twisting foce

Question 9

underspeed vs overspeed

Question 10

windmilling

Answer 10

causes drag, relative wind strikes face of prop

Question 11

feathering and feathering lock

Answer 11

nitrogen, feathering spring and flyweights are used to feather the lock

feathering lock
- for engine start and shutdown
- easy start
- cannot be feathered anytime prop rpm below 950

Question 12

accumulator

Answer 12

sends oil thru prop governor
after engine restarts, oil pressure, nitrogen recompresses the accumulator

Question 13

landing gear uplock vs downlock

Question 14

landing gear pump

Answer 14

electrically powered bidirectional (reversible)hydaurlic pump

Question 15

landig gear schematic (4)

Answer 15

thermal relief: relieves pressure above 3000PSI caused by temp changes
shuttle valve: moes hydaruliic fluid to move actuators up/down
pressure switch: at 1800psi this switch shuts off hydraulic pump
restrictor: slows nose gear during retraction

Question 16

gear retraction

Answer 16

held in place by hydraulic pressure

Question 17

downloack siwtch

Answer 17

3 greens when down and locekd

Question 18

how many landing gear switches

Answer 18

right squat switch - prevents stall horn and maintenance hobbs metar op
left squat switch - prevents landing gear retraction
up limit switch - uplimit travel for nose wheel
down lock switch - deactivates pump when gear is flly extended
hydraulic pressure switch - deactivates pump when landing gear is retracted

Question 19

priming

Answer 19

can overprime engine
cylinder 3 is not primed
electric fuel pumps must be on to operate the electric fuel primers

Question 20

crossfeed

Answer 20

allows fuel to flow from opposite side to operating engine
select OFF on failed engine
contaminated fuel, engine failture

do not takeoff or land with fuel selector on xfeed

Question 21

PAST

Answer 21

P p factor (assymetrical thrust due to ascending/descending blade, slower more prominent)
A accelerated slipstream (airflow from thrust directly over the inboard portion of wing, lack of lift from the dead engine prop)
S spiraling slipstream (spinning air twisting around plane, lack of wind that hits rudder)
T torque (propeller turns right, airplane wants to roll left, high rpm)

Question 22

blue sky black earth

Answer 22

climb move blue
descend move black

Question 23

service ceiling vs single engine service ceiling

Answer 23

100fpm max density altitude where best rate of climb airspeed

single engine
50gpm altitude a twin engine airplane can no longer climb at a rate greater than 50rpm

Question 24

single engine performance considerations

Answer 24

critical engine vs non critical engine
extended flaps or landing gear
aircraft weight
Cg location

Question 25

what is a slip

Answer 25

a slip occurs when an airplane does not travel in the direction the nose is pointed

moves sideways than straight ahead

produces a large amount of drag

• want zero sideslip