wcobra Posted November 13, 2010 Report Share Posted November 13, 2010 To answer INS questions you must first understand the actual operation of an Inertial Reference Platform: First, an airplane knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it is not, or where it isn't from where it is (whichever is greater), the aircraft obtains a difference or deviation. The inertial navigation system uses deviation to generate corrective commands to drive the aircraft from a position where it is to a position where it isn't. Arriving at the position where it wasn't, it now is. Consequently, the position where it wasn't is now the position where it is, and it follows that the position where it was is now not the position where it isn't. In the event that the position where it is now is not the position where it wasn't, the system has acquired a variation. Variations are external factors and are beyond the scope of this discussion In simple terms, the variation is the difference between where the aircraft is and where it isn't. If variation is considered a significant factor, it may be corrected by the use of the Doppler system, however for this to work, the aircraft must also know where it was. The "thought process" of the system is as follows: Because a variation has modified some of the information, which the aircraft has obtained, it is not sure where it is. However, it is sure where it isn't (within reason...) and it knows where it was. It now subtracts where it should be from where it wasn't (or vice versa...) and by differentiating this from the algebraic difference between it's deviation and it's variation (which is called error), it computes the correct information to compensate for all factors, thus supplying accurate navigation information. In even simpler terms, the aircraft calculates the difference between where it is, where it was, at least two places where it isn't, and where it should be to determine the path to get where it wants to be. Spoken like a true E guy! Up until now, I thought Avionics was magic. I may have finally got it Quote Link to comment Share on other sites More sharing options...
Phil Croucher Posted November 13, 2010 Report Share Posted November 13, 2010 1.When an inertial platform system is operating on board an aircraft, it is necessary to use a device with the following characteristics, in order to keep the vertical line with a pendulous system: Without giving the game away, bear in mind that JAA questions require attention to detail - i.e they play mind games. Every word is important! There's usually an obvious answer that is not correct! I'm currently doing a book of pilot puzzles - would you guys like to try some? phil Quote Link to comment Share on other sites More sharing options...
Daz Posted November 13, 2010 Report Share Posted November 13, 2010 I'm currently doing a book of pilot puzzles - would you guys like to try some? phil Yes please! :up: Quote Link to comment Share on other sites More sharing options...
splitpin Posted November 13, 2010 Report Share Posted November 13, 2010 Yes please! :up: Right then. First question. WTF makes a Pilot tick??? :up: :up: Just kidding, carry on Phil. Quote Link to comment Share on other sites More sharing options...
FREDDIE Posted November 14, 2010 Report Share Posted November 14, 2010 Answer to what makes a pilot tick. Is seeing a engineer tock. Quote Link to comment Share on other sites More sharing options...
old dog Posted November 14, 2010 Report Share Posted November 14, 2010 Right then. First question. WTF makes a Pilot tick??? :up: :up: Just kidding, carry on Phil. Beer, mostly. Quote Link to comment Share on other sites More sharing options...
pilot5 Posted November 14, 2010 Author Report Share Posted November 14, 2010 Interial Navigation systems operate as was aptly explianed. The pilot enters a reference latitude. The answer to the question is A, with damping and a period of 84 minutes 24. For an aircraft on ground what signal may be used by ATC to mean; return to starting point on the aerodrome? a. continuous green light b. flashes of green light c. continuous white light d. flashes of white light 25. You are landing at an aerodrome where landings are not confined to a runway. One aeroplane has already landed. a. you will land immediately behind the other aeroplane. b. when landing you will leave the other aeroplane clear on your right. c. when landing you will leave the other aeroplane clear on your left. Choose the correct answer. Quote Link to comment Share on other sites More sharing options...
Phil Croucher Posted November 14, 2010 Report Share Posted November 14, 2010 Actually, I believe the answer should be with damping and the period is about 84 minutes - 84 minutes being the Schuler tuning. Which database are you using? Here's a good example of a JAA question. The flux valve of a gyro magnetic compass: a) is pendulously mounted and remains aligned with the earth magnetic field. is fixed to ans turns with the aircraft to create a field which is used to measure the angle between the aircraft and the earth magnetic flux lines. c) is not subject to turning and acceleration error. d) is pendulously suspended and is not affected by the vertical component of the earth magnetic field. They very often require the least wrong answer! Others follow! phil Quote Link to comment Share on other sites More sharing options...
pilot5 Posted November 14, 2010 Author Report Share Posted November 14, 2010 Not sure what data base? but about seems like the right answer. But according to my answer sheet its 84minutes. Hmmmm. It could bee out by .001% and therefor about is a better answer. Thought I'd pick a few easier ones. These questions are for the most part designed to cause a bad wrong answer and the language is sooooo important. Cheers P5 Quote Link to comment Share on other sites More sharing options...
Daz Posted November 14, 2010 Report Share Posted November 14, 2010 24. For an aircraft on ground what signal may be used by ATC to mean; return to starting point on the aerodrome? a. continuous green light b. flashes of green light c. continuous white light d. flashes of white light That's (d.). I've only had one PPC (so far) but the light signals was one of the questions, IIRC. I'm fuzzy on the runway one - I better go learn (or remind myself) the answer as it looks to be a good one to know. Helicopters are often not confined to runways, after all... Cheers, - Darren Quote Link to comment Share on other sites More sharing options...
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