Does the engine fails as a result of complete electrical failure

11 Answers

1. 
   

   
   

   Aaron on Nov 05, 2013

   nope. engine systems are completely independent of the electrical system, outside of the starter and it’s a darn good thing they are too! think about the consequences of a dead battery or a dead alternator. you wouldn’t want that to bring you out of the sky. check your POH for the specifics of the system. engine systems use magnetos to power the spark plugs. The magnetos are basically giant electromagnets that beverage a current with a wire coil and a magnet. it uses the engine’s mechanical energy to turn and produce current fir the spark plugs. in this sense, once the engine is running, you’ll have power until the magnetos fail or you run her out of gas. It’s usually the latter 😉

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2. 
   

   
   

   Mark Kolber on Nov 05, 2013

   I had a student who was convinced that the prop was a “fan” that turned electrically and we would fall out of the sky if the electricals failed. So, one day in the practice area, I turned off the master/alternator switch.

   Lion, you want an reference? Try the POH. It’s basic to how the magneto system works (does you lawnmover need a battery)? You might look at any reference that discusses magneto-based powerplant systems including AC 65-12A, the Airframe and Powerplant Mechanics Powerplant Handbook or a lawnmower repair manual 😀

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3. 
   

   
   

   Lion on Nov 05, 2013

   Not only me 🙂

   This question is among the questions of India DGCA for PPL written test.

   The answers above would be wrong because the question says COMPLETE electrical failure not complete electrical SYSTEM failure. Technically, the magnetos are electricity generating source but they operate independent of the electrical SYSTEM failure.

   When we say “electrical SYSTEM”, we mean battery, alternator, buses, CB…etc. but when we say electrical without the word “system”, we mean ANYTHING installed in the airplane that generate useful electricity. This question is just another question of those tricky ones written by the many international civil aviation authorities. The odd is that they take many FAA questions and they twist them around and that’s what makes many applicants with FAA licenses fail the first foreign pilot written test attempt.

   -2 Votes 0 Votes  2 Votes

4. 
   

   
   

   Lion on Nov 05, 2013

   Not only me 🙂

   This question is among the questions of India DGCA for PPL written test.

   The answers above would be wrong because the question says COMPLETE electrical failure not complete electrical SYSTEM failure. Technically, the magnetos are electricity generating source but they operate independent of the electrical SYSTEM.

   When we say “electrical SYSTEM”, we mean battery, alternator, buses, CB…etc. but when we say electrical without the word “system”, we mean ANYTHING installed in the airplane that generate useful electricity. This question is just another question of those tricky ones written by many international civil aviation authorities. The odd is that they take many FAA questions and they just twist them around and that’s what makes many applicants with FAA pilot licenses fail the first foreign pilot written test attempt.

   0 Votes 1 Votes  1 Votes

5. 
   

   
   

   Mark Kolber on Nov 05, 2013

   Well, if they want to use a trick question to get people to fail, rather than test knowledge, not much can be done other than look for the answer they want and play the game.

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6. 
   

   
   

   Mark Kolber on Nov 05, 2013

   OTOH, your question specifically stated “complete electrical failure (no alternator and no battery)” so the answers given were correct.

   0 Votes 1 Votes  1 Votes

7. 
   

   
   

   Lion on Nov 06, 2013

   Mark,
   “OTOH, your question specifically stated “complete electrical failure (no alternator and no battery)” so the answers given were correct.”

   No Mark, the question center around the engine failure or not. the answers above say that the engine still will operate in case of a COMPLETE electrical failure which is not accurate answers. The engine will not be affected if the electrical SYSTEM ONLY failed but not if a COMPLETE electrical failure takes place.

   Here are some more questions but from the JAA:

   1. In a fused circuit the fuse is:

   a) in parallel with the load.
   b) in series with the load.
   c) in the conductor between generator and regulator.
   d) only fitted when loads are in series.

   2. Overloading an electrical circuit causes the fuse to ‘Blow’. This:

   a) increases the weight of the insulation.
   b) fractures the fuse case.
   c) disconnects the fuse from its holder.
   d) melts the fuse wire.

   3. What must be checked before replacing a fuse:

   a) the ohms of the circuit.
   b) the amps being used in the circuit.
   c) the amps capacity of the consuming device in the circuit.
   d) the correct fuse volt or watts rating.

   4. The size of fuse required for an electrical circuit whose power is 72 watts and whose voltage is 24 volts is:

   a) 24 amps
   b) 10 amps
   c) 5 amps
   d) 15 amps

   +2 Votes 3 Votes  1 Votes

8. 
   

   
   

   Lion on Nov 06, 2013

   5. To prevent circulating currents when more than one generator is being connected to the same bus bar:

   a) reverse current relays are fitted.
   b) the generators are connected in series.
   c) rectifiers are fitted.
   d) differential cut-outs are used.

   6. A generator cut-out is fitted:
   a) in series with the generator output.
   b) in the diode circuit.
   c) in parallel with the generator output.
   d) in the field circuit.

   7. On a 28 volt system with a 24 volt battery the cut-out contacts close at approximately:
   a) 36 volts.
   b) 24 volts.
   c) 28 volts.
   d) 26 volts.

   8. A component whose job is similar to a generator cut out is:
   a) a rectifier.
   b) a converter.
   c) an inverter.
   d) a reverse current relay.

   9. If the cut-out is open, the battery is feeding the loads which are:
   a) in series with the battery.
   b) in parallel with the battery.
   c) in sequence with the cut-out.
   d) cross coupled.

   10. A voltage regulator is fitted to:
   a) prevent high circulating currents.
   b) prevent backlash.
   c) to ensure correct voltage output to battery.
   d) to prevent battery feedback to the generator.

   11. If an aircraft electrical system is quoted as 24 volts DC the output of the generator is:
   a) 12 volts with the generators connected in series.
   b) 28 volts with the generators connected in parallel.
   c) 36 volts with the generators connected in series/parallel.
   d) 42 volts.

   12. If a circuit is designed for 12 volts – the generator will:
   a) give parallelled output only.
   b) give controlled 14 volts.
   c) 14 volts wild DC.
   d) give controlled 12 volts.

   13. The aircraft electrical generator output is controlled in flight by:
   a) sensing the generator output pressure.
   b) ram air.
   c) a resistance in the generator output circuit.
   d) the resistance of the armature circuit.

   14. In a generator control circuit the strength of the magnetic field is controlled by:
   a) the commutator.
   b) the voltage regulator
   c) the reverse current contactor.
   d) the output C/B.

   +1 Votes 2 Votes  1 Votes

9. 
   

   
   

   Mark Kolber on Nov 06, 2013

   Read your question, Lion.

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10. 
    

    
    

    Bob Watson on Nov 06, 2013

    I always thought the ELECTRICAL system was all the things that were, in one way or another, connected to the (a) battery. The IGNITION system was what sparked the engine to life. While the ignition system uses electricity, I don’t think that makes it part of the electrical system. Of course, some of the new engines with electronic ignition and other computerized engine controls blur this line, perhaps to the point that losing power on the electrical system could cause engine failure (didn’t that happen on the Diamond twin a while back?)

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11. 
    

    
    

    Brian on Nov 07, 2013

    Mark, “Read your question, Lion.”

    Read? Hah. This is a joke right? Reading is what you pay lawyers unlawful amounts of money to do for you. 😉

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