Mesa Airlines E175 Systems Study Guide
questions with correct answers
How many engine driven generators? Rating? CORRECT ANSWER-2 IDGs
(Integrated Drive Generators)
115VAC, 400Hz, 40KVA
What kind of APU? Rating? CORRECT ANSWER-Sundstrand APS 2300
115VAC, 400Hz, 40KVA
What is the RAT rated at? CORRECT ANSWER-115VAC, 400Hz, 15KVA
What is the Normal AC Electrical Priority? CORRECT ANSWER-- Onside (IDG)
- Inside (APU)
- Outside (GPU)
- Cross-side (Opposite IDG)
When does the RAT automatically deploy? CORRECT ANSWER-Loss of all AC
power in flight (electrical emergency)
What are SPDAs and what do they do? CORRECT ANSWER-(Secondary Power
Distribution Assemblies)
- 2 Total
- Electrical load management unit
- Receives power from ICCs
- Distributes power according to system logic
,What are ICCs and what do they do? CORRECT ANSWER-(Integrated Control
Center)
- 4 Total
- Collects & confirms power is safe
- Sends power to SPDAs
What's on DC HOT BUS 1? CORRECT ANSWER-- Engine 1A/2A Fire
Extinguisher
- Engine Fuel Shutoff Valve 1
- Hydraulic Shutoff Valve 1
- Engine 1 oil level indication
- Courtesy/Service Lights
- DC Ceiling Lights
What's on DC HOT BUS 2? CORRECT ANSWER-- Engine 1B/2B Fire
Extinguisher
- Engine Fuel Shutoff Valve 2
- Hydraulic Shutoff Valve 2
- Engine 2 oil level indication
- CMC (Central Maintenance Computer)
- Panel Refuel
- Water & Waste System
How many networks make up the electrical system on the airplane? Why?
CORRECT ANSWER-- 2 independent networks
- Redundancy and fault isolation
, What happens if a power generating source fails? CORRECT ANSWER-Bus ties
automatically connect to provide no system degradation
What components power the AC system? CORRECT ANSWER-- 2 Integrated
Drive Generators (IDG)
- Auxilliary Power Unit (APU)
- Ram Air Turbine (RAT)
- AC GPU receptacle
- Inverter
What components power the DC system? CORRECT ANSWER-- 2 NiCad
batteries
- 3 Transformer Rectifier Units (TRU)
- DC GPU receptacle
How does the IDG maintain a stable power output? CORRECT ANSWER-A
Constant Speed Drive (CSD) attaches the IDG to the Accessory Gear Box (AGB)
What monitors and controls the IDGs? CORRECT ANSWER-Each IDG has a
Generator Control Unit (GCU)
Can one IDG supply the entire electrical system? CORRECT ANSWER-Yes
What will cause the amber IDG light on the electrical overhead panel to
illuminate? CORRECT ANSWER-- High oil temperature
- Low oil pressure
questions with correct answers
How many engine driven generators? Rating? CORRECT ANSWER-2 IDGs
(Integrated Drive Generators)
115VAC, 400Hz, 40KVA
What kind of APU? Rating? CORRECT ANSWER-Sundstrand APS 2300
115VAC, 400Hz, 40KVA
What is the RAT rated at? CORRECT ANSWER-115VAC, 400Hz, 15KVA
What is the Normal AC Electrical Priority? CORRECT ANSWER-- Onside (IDG)
- Inside (APU)
- Outside (GPU)
- Cross-side (Opposite IDG)
When does the RAT automatically deploy? CORRECT ANSWER-Loss of all AC
power in flight (electrical emergency)
What are SPDAs and what do they do? CORRECT ANSWER-(Secondary Power
Distribution Assemblies)
- 2 Total
- Electrical load management unit
- Receives power from ICCs
- Distributes power according to system logic
,What are ICCs and what do they do? CORRECT ANSWER-(Integrated Control
Center)
- 4 Total
- Collects & confirms power is safe
- Sends power to SPDAs
What's on DC HOT BUS 1? CORRECT ANSWER-- Engine 1A/2A Fire
Extinguisher
- Engine Fuel Shutoff Valve 1
- Hydraulic Shutoff Valve 1
- Engine 1 oil level indication
- Courtesy/Service Lights
- DC Ceiling Lights
What's on DC HOT BUS 2? CORRECT ANSWER-- Engine 1B/2B Fire
Extinguisher
- Engine Fuel Shutoff Valve 2
- Hydraulic Shutoff Valve 2
- Engine 2 oil level indication
- CMC (Central Maintenance Computer)
- Panel Refuel
- Water & Waste System
How many networks make up the electrical system on the airplane? Why?
CORRECT ANSWER-- 2 independent networks
- Redundancy and fault isolation
, What happens if a power generating source fails? CORRECT ANSWER-Bus ties
automatically connect to provide no system degradation
What components power the AC system? CORRECT ANSWER-- 2 Integrated
Drive Generators (IDG)
- Auxilliary Power Unit (APU)
- Ram Air Turbine (RAT)
- AC GPU receptacle
- Inverter
What components power the DC system? CORRECT ANSWER-- 2 NiCad
batteries
- 3 Transformer Rectifier Units (TRU)
- DC GPU receptacle
How does the IDG maintain a stable power output? CORRECT ANSWER-A
Constant Speed Drive (CSD) attaches the IDG to the Accessory Gear Box (AGB)
What monitors and controls the IDGs? CORRECT ANSWER-Each IDG has a
Generator Control Unit (GCU)
Can one IDG supply the entire electrical system? CORRECT ANSWER-Yes
What will cause the amber IDG light on the electrical overhead panel to
illuminate? CORRECT ANSWER-- High oil temperature
- Low oil pressure
