Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

#B787 Electrical, Engines, Fire protection (ultimate) > Ch. 6 Electrical > Flashcards

Ch. 6 Electrical Flashcards

1
Q

The bus power control units provide electrical load management when the aircraft is operating on:

A

Any available electrical power source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

if the permanent magnet generators are not available, the flight control electronics receive power from the:

A

28v DC system and main battery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the minimum number of external power sources required for an external power ONLY engine start?

A

Two (L fwd, R fwd)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the ground handling mode is powered when ____ if no other power sources source is available.

A

either FWD external power is connected (avail)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the generator drive may disconnect automatically ____

A

depending on the fault condition detected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how can the flight crew determine circuit breaker status?

A

check the CBIC display

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the purpose of the permanent magnet generators (PMGs)

A

powers the flight control electronics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Towing power panel

when pressing the towing battery test switch, what do the following “battery state of charge indicators” mean?

high
medium
low

A

high: a minimum of 60 min remaining before battery charge is depleted
medium: a minimum of 30 min
low: 15 min

  • minimum times assume steady state towing (no braking) before batteries are depleted. if heavy breaking occurs, actual time remaining may fall below the minimum times listed.

AOM 6.10.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does the b-787 electrical system power?

A 
engine start
pressurization
wing ice protection
stabilizer trim
wheel brake systems

AOM 6.20.1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the electrical power sources?

A

4 variable frequency engine starter/generators
2 variable frequency APU starter/generators
3 external AC power receptacles
1 RAT
1 main battery
1 APU battery
3 flight control permanent magnet generators (PMG)
2 EEC permanent magnet alternators (PMA)

AOM 6.20.1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

electrical power for APU start can be provided by…?

A

FWD external power
APU battery
engine generated power

  • for APU starts with the APU battery as the power source, the right starter/generator is always used. either a left or right is for APU start when an engine is running or the FWD external power is selected ON.

AOM 6.20.2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When does the RAT deploy?

A

Both engines have failed
All 3 hydraulic system pressures are low
Loss of all electrical power to captain’s and first officer’s flight instruments
Loss of all 4 EMPs and faults in the flight control system occur on approach

AOM 6.20.3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens when the main and/or APU battery experiences a severe failure and overheats?

A

A sealed enclosure ensures the resulting heat and gases are contained so they pose no hazard to the airplane and it’s occupants.

if the heat and gases reach a level normally associated with a cell failure, a burst disk on the enclosure activates, venting gases directly overboard through a vent tube opening in the fuselage.

the main battery vent is located aft of the FWD E/E door, near the airplane centerline. A brief odor may be present in the flight deck just prior to the main battery disk activation.

The APU battery vent is located AFT E/E compartment.

AOM 6.20.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the permanent magnet generators used for?

A

Primary source of power for the flight control electronics.

These power sources are independent from the main airplane electrical system, and are also independent from each other.

AOM 6.20.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What’s the secondary source for flight controls?

A

The airplane’s 28 Vdc bus distribution system
Main battery
Dedicated batteries to assure positive flight control operation during temporary power interruptions

AOM 6.20.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What do the Permanent Magnet Alternators power? (1 per engine)

A

Primary source of power for the EEC

AOM 6.20.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What’s the secondary source of power for the EECs?

A

Secondary source of power is provided by the airplane’s 115v AC bus distribution system.

AOM 6.20.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are RPDU’s and how many does the B-787 have?

A

Remote power distribution units (the lower amperage (10 amps or less) loads are distributed by the RPDUs)
17

AOM 6.20.6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens when there is 1 FWD external power connected and you start the APU or an engine?

(concerning the 235 Vac 4 main buses)

A

The APU or engine automatically powers the 4 main 235 Vac buses, and external power transitions from ON to AVAIL

AOM 6.20.8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What powers the brakes?

A

the brakes are powered by 4 electrical power supply units.
they are powered by two separate 28Vdc inputs, 1 from the 28Vdc bus system, 1 from the main battery.

28Vdc bus system is primary
main battery is backup

AOM 6.20.9

21
Q

what are PECS and when are they energized?

A

Power electronics cooling system

Energized when:

1 or both engines are running
APU running
FWD ext power is connected and selected on

AOM 6.20.9

22
Q

The B-787 has several Electrical load management modes, what are they?

A

Towing power mode:

active when TOWING POWER switch is selected ON (with the main battery switch OFF)
Main and APU battery energize only the equipment essential for towing ops.
radio comes are not energized in towing mode.

On-ground battery mode only:

Battery switch connected ON and no other power sources connected.
this mode is to support the airplane power-up sequence.

Ground handling mode:

Active when first FWD ext power is connected but not selected ON.
Ground handling mode has priority over On-ground battery only mode, and initialized regardless of BATT switch position.

Ground service mode:

is active when the GROUND SERVICE switch on the master attendant switch panel is selected ON while in ground handling mode.
powers cabin systems and lighting etc.

External power on mode:

active when at least 1 FWD external power receptacle is connected and selected ON with the APU and engine GENs off.
more loads are energized when’s 2 FWD ext power sources are connected.
*packs and cargo heat are inop in this mode

In air RAT only mode (standby power)

active when all electrical power is lost to both captain’s and FO’s flight instruments. energizes captains flight instruments and other essential equipment.

In air battery only mode:

same as in air rat mode with the exception of center pitot heat.

AOM 6.20.13

23
Q

The bus power control units provide electrical load management when the aircraft is operating on:

A

any available electrical power source.

24
Q

If the permanent magnet generators are not available, the flight control electronics receive power from the:

A

28v DC system and main battery.

25
Q

What is the minimum number of external power sources required for an external power ONLY engine start?

A

Two (L&R Fwd)

26
Q

The ground handling mode is powered when _____ if no other power source is available.

A

either FWD external power is connected (AVAIL)

27
Q

The generator drive may disconnect automatically _____.

A

depending on the fault condition detected

28
Q

How can the flight crew determine circuit breaker status?

A

Check the CBIC display.

29
Q

What is the purpose of the permanent magnet generators (PMGs)?

A

Powers the flight control electronics.

30
Q

The main battery power to the following:

A

A. electric breaking (as backup source).
B. The Captains Flight instrument bus until RAT deployment
C. Towing and refueling operations

31
Q

If a loss of all electrical power to Capt’s and FO’s flight instrument occurs in flight, the _____ provides Standby Power until RAT deployment.

A

Main battery

32
Q

How can crew members differentiate between an open Electronic circuit breaker (ECB) and an open Thermal circuit breaker (TCB)?

A

Open TCB’s are shown using a crosshatched diplay while ECB’s are solid white.

33
Q

If any engine generator fails, how is power provided to it’s associated main AC bus?

A

The lost main AC bus is now powered be another main AC bus.

34
Q

The Large Motor Power Distribution System (LMPS) powers _____.

A

A. CAC’s
B. Hydraulic pumps
C. power for APU and Engine starting

35
Q

During an autoland approach with LAND 3 annunciated below 200ft, the R1 starter/generator fails. What does the ASA show?

A

The ASA continues to display LAND 3.

36
Q

After landing, PECS cooldown begins when ____?

A

Packs AND hydraulic EMPS’s are shutdown

37
Q

The standby electrical system consists of:

A

The Main battery and the RAT generator.

38
Q

Primary and backup power for the brake system is provided by:

A

28vdc power for the primary system and the main battery for the backup source.

39
Q

What is the difference of electrical system between B8 and B6?

A

Electrical System: (AOM 6.20.1)
System powers engine start, pressurization, wing ice protection, stabilizer trim and wheel brakes.
2x Starter/Generator on each engine and APU giving total of 6.
B787 main buses are 235Vac.
3x independent PMG to power primary flight controls
2x independent PMA to power EEC
3x External Power Receptacles.
Batteries are Lithium

40
Q

Explain about the outline of the battery system?
AOM6.20.4

A 
1 MAIN battery 
1 APU battery 
*8 cells each, 4V output for each cell = 32 V all 8 cells 
MAIN battery provides power for: 
⁃ airplane power-up
⁃ APU start (assists APU battery) 
⁃ Refueling ops 
⁃ Towing ops 
⁃ Electric braking (back up source) 
⁃ Captains flight instruments (power failure, energizes essential instruments until RAT deploys) 
(with no RAT 10 minutes battery power available) 
APU provides power for: 
⁃ APU start 
⁃ Navigation lights (when towing power mode is active)
41
Q

What are the changes after battery accident?
INFORMATION 067A 14 NOV 2013

A

⁃ Elimination of the possibility of short circuits and overheating.
⁃ Improved thermal insulation between cells.
⁃ Improved heat resistance.
⁃ Elimination of the possibility of damage attributable to moisture.
⁃ Improved manufacturing process and quality.
⁃ Seal closures that have venting disks in case of excessive high temps and gases.

42
Q

Where is the battery?

INFORMATION no. 067A issue: NOV 14, 2013

A

MAIN battery: Fwd E/E compartment
APU battery: Aft E/E compartment

43
Q

If the main battery fail in the air, will it affect any system?
INFORMATION no. 067A issue: NOV 14, 2013

A

Since design changes all vapor from a main or APU battery fail are vented
outside the aircraft. There are no smoke detector to detect these vapors.

  • The batteries are physically isolated from the surrounding equipment and cabin
    air system.
  • There will be no oxygen within the enclosure and combustion will not occur.
44
Q

Explain about the outline of the electrical?
AOM 6.20.1

A 
115VAC primary 
28 Vdc primary 
235 Vac - limited systems 
⁃ 4 Engine starter/generators 
⁃ 2 APU starter/generators 
⁃ 3 external AC receptacles 
⁃ 1 RAT 
⁃ 1 MAIN battery 
⁃ 1 APU battery 
⁃ 3 Flight Control PMG’s (Permanent Magnet Generators) 
⁃ 2 EEC PMA’s (Permanent Magnet Alternators)
45
Q

What systems operate by electrical power, previously hydraulic power?

A
  • wheel brakes
46
Q

For what is the AFT EXT PWR used ?

A

The aft external power system can assist the forward system when starting the
right engine first. (AOM6.20.3)

47
Q

Stabilizer runs on Electricity, so any threats?
(AOM 9.20.2)

A

In the unlikely event of the loss of all hydraulic power, the electrically actuated
Stabilizer and the two spoiler pairs allow pilot control of pitch and roll using the
Primary pitch trim switches, alternate pitch trim switches, and the control wheel.
If there is a complete loss of flight control signaling, direct wiring from the flight deck
To the stabilizer and the spoiler pair allow pilot control of pitch using alternate pitch
Trim switches and roll using the control wheel.

48
Q

What runs on Electricity?
(AOM 6.20.1- 6-20-7)

A 
Electrical power sources are: 
 
 *Four variable Frequency engine starter/generators 
 *Two variable Frequency APU starter/generators 
 *Three external AC power receptacles 
 *One Ram Air Turbine (RAT) 
 *One main battery 
 *One APU battery 
 *Three flight control Permanent Magnet Generators 
 *Two EEC Permanent Magnet Alternators 
A. Primary 115 Vac Loads: 
 Cabin Exterior lighting 
 Cabin Systems & IFE 
 Galley Power 
 GPWS, WXR 
 Transponder, TCAS 
 Window HEAT 
 HF-SATCOM 
 Primary 28 Vdc Loads: 
 Ground Operations 
 Common Core System 
 Audio & VHF Com 
 Auto Pilot / Auto Throttle 
Engine Igniters 
 DC Fuel Pump
 Brake Power 
 Secondary FCTL Power 
 Backup FCTL power 
 Standby power 
 Primary 235 Loads: 
 Wing ice protection 
 ECS Recirc fans 
 Main Tank fuel Pumps 
 Cargo Heaters 
 Spoilers 
 Stabilizer 
 Alternate Flaps 
 Equipment cooling 
 Galley Refrigeration 
 Aft Galley complex

#B787 Electrical, Engines, Fire protection (ultimate) (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions