Seminole Systems Flashcards
Ignition system?
Impulse coupling- provides rotation for hot spark (450rpm).
High pitch, low rpm?
Nitrogen, spring, counter weights.
Unfeathering accumulator?
Stores engine oil under pressure.
Brings the prop out of the feathered position and reduces wear and tear on the starter.
Feathering time?
10-17 sec.
Anti-feathering pins?
Prevents the prop from feathering during shutdown. Doesn’t allow below 950 rpm.
Semi ailerons?
Differential frise- reduces adverse yaw, adds drag (parasite).
23 degrees up and 17 degrees down.
Describe the landing gear system?
Hydraulically operated, electrically powered, tricycle landing gear.
12 volt reversible pump.
What limitations are associated with the landing gear?
Vle- gear extended speed (140)
Vlo- gear operation speed (140)
Vret- gear retract speed (109)
Where is the hydraulic fluid stored for the landing gear?
Baggage
Do the brakes and gear use the same hydraulic fluid? Are they taken from the same place?
Yes. No, brakes is located in the nose.
What holds the landing gear up?
Hydraulic pressure - below 1300 psi the pump goes on again.
What turns off the gear hydraulic pump during retraction?
Pressure switch at 1800 psi.
What turns the 3 green indicators?
Down limit switches.
What keeps the gear down and locked?
Downlock hooks and springs.
What causes the gear unsafe light to illuminate?
- gear not full up or down
- MAP below 14” with the gear up
- flaps more than 2nd or 3rd notch
How long does it take for the gear to be retracted or extended?
6-7 seconds.
Why is there a thermal relief valve?
Protects it from temperature and pressure changes (3000 psi) by releasing excess pressure as the airplane climbs or descends.
Alternators?
Two 14 volt 70 ampere.
Battery?
12 volt 35 ampere-hour
Overheat switch?
Approx 450 degrees (+/- 80)
Where does the combustion heater take fuel from and how much?
Left fuel selector, 1/2 gal/hr.
What are the limitations of the AP?
- 185 kts max
- 80 kts min
- no more 25 degrees flaps
- prohibited TO/LND
- missed appch and go around
- CAT I only
- no SE appch
- 200 ft below
- manual must be on board
What type of engine Seminole has?
2 engines: 180 HP 2700 RPM O-360-A1H6 (LO- right) 4 cylinder Direct drive Full feathered Air cooled Horizontally opposed Carbureted
What type of oil?
MIL-L-22851 Ashless Dispersant
What type of prop?
2 blade hartzell Constant speed Hydraulically actuated Full feathering 72-74"
Low pitch, high rpm?
Oil and aerodynamic twisting force
Unfeathering time?
8-12 seconds
Why is the landing gear retraction speed slower then the extension speed?
Because the nose wheel will unlock and ram air will push the nose wheel back into the wheel well.
What does the left squat switch do?
Prevents accidental gear retraction on the ground.
What does the right squat switch do?
Activates the stall warning.
Starts the MX Hobbs time.
What does the up-limit switch on the nose gear do?
Turns off the heater blower.
Brakes systems?
Two single-disc, double-puck brake assemblies.
Electrical system?
Negative-ground, dual-fed, split-bus system.
What does the ACU (alternator control unit) do?
It uses a voltage regulator and a overvoltage relay.
Regulators- maintain 14 volts between the two (load sharing).
Relay- will take the alternator offline if exceeds 17 volts.
Six bus bars which distribute electricity?
- Battery bus (clock, flight times)
- Avionics bus #1 (comm nav 1, xponder, pitch trim)
- Tie bus
- Main bus (lights, pumps, starter, pitot heat)
- Avionics bus #2 (comm nav 2)
- Non-essential bus (cabin heater, vent, blower)
