Questions tagged [electrical-system]

The parts of an aircraft that produce electrical power (such as generators/alternators, batteries, and ram air turbines) and distribute it to the aircraft's systems.

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6
votes
1answer
230 views

Do I need a ferry permit for an alternator repair ferry flight within a mode C veil?

My Cessna 172 SP's alternator died while stationed at a class D airport, less than 10 miles from my home field (another class D). Both airports are within the mode C veil of a nearby B airport. ...
10
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2answers
1k views

What are the advantages of using DC electric power over AC, as e.g. done in the EMB 135/145?

In this question I can see the advantages of using AC electric power over DC in large aircraft. However, Embraer decided to produce a "DC aircraft": the ERJ 135/145. What are the advantages ...
3
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4answers
2k views

What component of an aircraft generates its electric power?

What component of an aircraft generates the electric power to start the aircraft's engine? For a Rotax 912 engine, I think the magneto generates the electricity, but I'm not sure; I also think about ...
-1
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3answers
186 views

What amount of electricity could we get from the Seebeck effect on a kerosene turbofan?

Edit: I rewrote my post. To downvoters, can you comment on your reasons? As a kind reminder: Downvote questions that don't show any research effort or don't contain enough information to be clear and ...
4
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2answers
258 views

Why is the alternator connected only to one electrical bus in the C152?

I am a noob in electrics so pardon my ignorance. What I see from an electrical system of C152 (pasted below): there are two busses, connected to each other, but alternator is fed only to the first bus....
5
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1answer
719 views

Why battery voltage is lower than system/alternator voltage

I’m a noob in electricity so pardon for my ignorance. Why the battery voltage is always lower than whole system and alternator voltage (considering light aircraft electrical system). E.g. In Cessna ...
6
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1answer
283 views

Can I do an alternator check at idle in a C152?

I have one question about alternator check in Cessna 152. During engine run-up we should check whether alternator is working or not, so we switch it off and then the warning light should illuminate. ...
0
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1answer
185 views

Where can I find maintenance manuals for the A380?

My friend recently acquired an external green light from an A380. They are the only details i have from him. I tried hunting the internet for maintenance manuals, technical details, schematics, ...
5
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2answers
2k views

Why is the battery turned off for checking the voltage on the A320?

Preliminary cockpit preparation section requires BAT check for 25.5V with BAT off (The beginning step). Since BAT indicator always show respective voltage, why they must be switched off?
19
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3answers
4k views

Can a completely drained battery be recharged via ground power on an airliner like the B737?

When accidentally leaving the battery switch or something powered by the hot battery bus on over night, an aircraft's battery could completely discharge. Normal startup, where the battery is switched ...
29
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8answers
7k views

Why do we still need ammeters?

I just received my private pilot's certificate 2 weeks ago, yay! Earlier today, a fellow at work who has 700ish hours walked in and asked my office-mate-electrical-engineer "why do we still need ...
2
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2answers
145 views

Can I safely plug something that draws 6 amps into the cigar lighter (power port) in my Piper Archer lll?

Can I safely plug something that draws 6 amps into the cigar lighter (power port) in my Piper Archer lll ?
1
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1answer
176 views

Will reducing the electricity power in an aircraft save fuel?

I was wondering if I reduce the power consumed by the aircraft, would the generator produce less power and if that would save some fuel.
1
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1answer
455 views

Why are these steps performed on the A330 emergency electrical checklist?

For an Airbus A330 in emergency electrical configuration with both generators and APU FAIL (both engines working), why does the checklist ask you to select RAT MAN ON before slat extension and then ...
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6answers
310 views

Would a piston or turbine engine be best suited for a small UAV flying 8000miles?

I am trying to devise a concept that would airdrop medical supplies around remote regions of Africa: vaccines, medicine, blood... etc. I image the payload would be anywhere between 1-2 ton. I think a ...
2
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0answers
102 views

How many smoke detectors does the A340 cargo deck have, and how are they wired?

I am a student of Aerospace Engineering, currently I am one year away from completing my degree. For my Electric Routing class I was asked to recreate in Catia the fire system in the cargo bay of an ...
2
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0answers
121 views

What is the cost of electricity generated in the E175-E1?

I'm comparing two types of cabin illumination, and I'm having a difficult time to estimate the cost that will be saved by utilizing lights with a lower power consumption. What are the costs of ...
5
votes
1answer
318 views

Why can APU supply both bleed air and electrical power up to 10.000 feet but bleed air alone up to 17000?

I am reading my company's FCOM and I saw there the following information. APU Bleed + Electrical Load: Max Alt 10000 ft. APU Bleed: Max Alt 17000 ft. APU Electrical Load: Max Alt 41000 ft. If APU ...
10
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3answers
3k views

What happens with the avionics if in midair there is loss of power or fuel flow interrupted? [duplicate]

What happens if in midair there is loss of power, how will the avionics perform in such a situation (cockpit display, flight plan)?
6
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1answer
714 views

Why are the 737's variable-speed generator drives so unreliable?

The 737 Classic has two different possible styles of engine-driven generators, distinguished by the generator's drive mechanism: the constant-speed drive (CSD) and the variable-speed constant-...
2
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2answers
487 views

Are the A320's A and B electrical buses both energized all of the time during flight?

I'm a novice reading a quick study guide. For electric power, I notice that the A320 has two buses: A and B. Are they both energized all of the time during flight? If not, is there a way to switch ...
4
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1answer
1k views

If an A320 loses an engine why does the landing category go to CAT3 single?

Following an A320 engine failure, why does the the landing category go to CAT3 single even if the APU has been started and is powering the AC bus that was lost by the failed engine?
3
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2answers
274 views

Why do the DC-9’s three-phase electrical systems use separate, unconnected breakers for each phase?

Aircraft electrical systems use two types of electricity: Direct current (DC),1 which always travels in the same direction (can be supplied directly from the aircraft’s battery, if necessary, but ...
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4answers
526 views

Is it possible to reload Electric Aircraft in mid-air from a tanker aircraft?

Can this be done military style refueling but with an electric wire boom supplying current from tanker aircraft to electric aircraft mid air in flight? Electricity from the tanker craft can be ...
5
votes
1answer
216 views

Where is the control loop of the actuator closed?

When electro-hydraulic servo-actuators are used for the actuation of control surfaces in aircraft, linear variable differential transformers (LVDTs) are used for position or velocity feedback. There ...
1
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1answer
752 views

How much power does the APU generate in a Boeing 737-300?

I have just watched Mayday episode 11, season 11, "Nowhere to Land" about TACA Flight 110 incident and I was more than surprised to learn that: APU must be turned on, APU needs about 5-10 minutes to ...
34
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4answers
16k views

What does "28 volts DC" mean, really?

The common battery voltage on aircraft is commonly referred to as "28 volts". What does that really mean in terms of a lead-acid battery? In many uses, such as cars ("12V"), trucks ("24V") ...
39
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7answers
8k views

What prevents a commercial jet from electronically "resetting" the way a computer sometimes does?

I've had a fear of flying for the past several years and one of the ways this irrational phobia manifests is concern over the airplane power-cycling in mid-air: engines cutting out, control equipment ...
6
votes
1answer
463 views

What is the battery voltage for a Supermarine Spitfire?

I am used to modern aircraft being 28V systems. I found an article saying that a trolley AC plug in battery used to start WWII aircraft was 12V. I'm trying to confirm or disprove this.
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2answers
1k views

How does the battery master switch activate the battery contactor in Cessna 152?

I have trouble understanding how the battery master switch activates the battery contactor in this schematic from the Cessna 152 manual. This is the model from 1979 or later with an Alternator Control ...
6
votes
3answers
2k views

Why does the low voltage warning light not illuminate when the alt switch is on, but the engine is off?

As part of the pre-flight inspection, one of the checks is to verify that the low voltage light is illuminated when switching just the battery on. This makes sense; there's a low voltage and the ...
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2answers
499 views

Where to find general A320 E&E Compartment Information?

I'm student in electrical engineering and write my thesis on some topic of the e&e compartment. The main focus is on the computers of the A320 flightcraft, actually called E&E Compartment. ...
3
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0answers
101 views

Why was the Tu-104 so prone to navball-disabling electrical power failures?

Of the (rather numerous) accidents involving the Tu-104, several were either caused or aggravated by major electrical failures, which disabled the aircraft's navballs, which caused the pilots to ...
14
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1answer
545 views

What's the plug used on airliners for ground power?

What's the plug pair called? What's the ISO/whatever standard involved? What do they look like close-up? Is it pretty standard today worldwide? Is the plug identical for the hugest airliners as for ...
14
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3answers
4k views

What powers an aircraft prior to the APU being switched on?

I know that APUs are power plants for non-propulsion related purposes and that they are turned on before takeoff. What powers an airplane prior to the APU being turned on?
6
votes
1answer
500 views

Why does the B737NG need electrical power for aircraft towing?

I have read the AMM for towing and one of the mentioned steps is to supply electrical power. Is it because you need power to turn on the hydraulics in order to pressurize your brakes? For B737NG
0
votes
1answer
222 views

Where can I find electrical pinout of C152 microphone jack and DC bias?

Would anyone have the pinout and/or specs of the C152 passenger/pilot microphone jack? I'd also like to know what DC bias voltage, if any, the plane provides to the microphone. Here's what I have so ...
5
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1answer
297 views

What is the source of emergency power for a 727?

I've found a couple of sources that state the 727's APU cannot be started while flying, as it draws air from the wheel well. It drew air from inside the wheel well, so it was only for use on the ...
5
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1answer
614 views

Why is the generator turned back off for starting the second engine on a King Air?

The engine start procedure for the Beechcraft King Air B200 says (emphasis mine): Right Ignition and Engine Start Switch – ON [R FUEL PRESS] annunciator – OFF Right Condition Lever – LOW IDLE (...
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0answers
329 views

What is the working principle of VFG [duplicate]

How does the VFG make various frequencies? And while it makes the other value of frequency, how the generator apply consistent 400Hz to the other component?
16
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1answer
3k views

What happens to Cessna electric flaps that are moving when power is lost?

On final in a C182T you move the flap control arm from 20 to FULL, and when halfway there, the breaker pops (or BUS1 fails, a wire falls off, etc.) Does the flap stay where it is, slide back to 20°, ...
6
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1answer
879 views

How can the F-16 remain stable when there is a loss of hydraulic power?

Edit for justification: This question is different from If the EPU (Emergency Power Unit) on a modern fighter jet fails, will the aircraft drop out of the sky? for the following reasons: The ...
8
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5answers
6k views

Has there ever been an airliner design involving reducing generator load by installing solar panels? [duplicate]

Has there ever been a trial/project/design, in which solar panels were incorporated in the design of a commerical airliner (e.g. on the wings), with the aim to reduce fuel consumption by lowering the ...
23
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2answers
3k views

Is aluminum electrical wire used on aircraft?

Aluminum electrical wire got a bit of a bad reputation in household wiring due to reacting badly with terminals not properly rated for aluminum. Properly handled, it works fine, but it's so ...
9
votes
1answer
953 views

What are possible causes for the flaps not deploying on a Cessna 172?

I would like to seek some expert opinion on why my flaps failed to deploy when I took it to Flaps 20. I was turning from Downwind to Base when I took flaps 20 and noticed that my speed was creeping ...
0
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0answers
70 views

Are there required standards for gate power cable maintenance?

I am looking for reference(s) addressing gate power cable maintenance, for both 28V DC and 400Hz. Do the FAA or any manufacturers have standards for measuring the connector pins to determine wear?
4
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0answers
219 views

Ground Power KVA when on stand

How much power from a GPU would a jet, say a Boeing 737, require when boarding passengers or just sat idle on the air bridge? I’m guessing the Aircraft would only consume the full 90kVA ground power ...
2
votes
3answers
626 views

Does the 2020 ADS-B -Out requirement apply to aircraft with only a wind-driven generator (electrical system)?

Since my J3 Cub was was not originally certificated with an engine-driven electrical system it's clear the 2020 ADS-B-Out mandate (U.S.) does not apply (except where specifically noted in FAR part 91)....
5
votes
2answers
543 views

What is the "off-side engine generator" on an A320?

For the A320 family, is the "off-side engine generator" the same as the "emergency generator driven by the RAT"? I can't find the location of the "off-side engine generator" on the A320.
4
votes
3answers
1k views

Why does load shedding still occur in jetliners (e.g., 787) when there is so much power available?

I had a few questions about how electrical generator works on an aircraft, the 787 to be specific although I know it is similar for all aircraft. So the 787 engines have 2 VFSG each which are rated ...