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annita
8th Dec 2009, 10:14
Hi guys,
a few questions came up today that have not seen before and thought to share them with you and if you could shine some light.

1.Fuel float gage is affected by?
attitude,acceleration,pressure.

I know the first two affect it but I thought the third will also as reducing the pressure will expand the fluid and the float measures volume.
Could not find anything in my books.
Opinions?

2.Gymbal errors on gyros is caused by?
I would expect that the answer would be excessive banking but the answers given were:
a. Apparent weight and acceleration
b. Slow prece. on the horizontal axis
Cant remember the other two but went for b.

3.TCAS II mearuses:
a. Mode C height
b. Altidute from the transponder.
c.Ground station data.
d..........

Went for b but found the wording a bit strange as some questions in the bank talk about height and others about altidute.

4.Autopilot inputs:
ADC,INS,Mode control panel,ILS
You had to choose and htought that ADC has no input as it feeds the INS which then feed the AP so I went for :INS,MCP,ILS.

As I said , have not seen them before.
Hope you could help a bit.

punk666
8th Dec 2009, 11:19
Hi,
its been a year or so since I did these exams and have gone a bit rusty on my theory but I guess not having a job gives me the time to revise right?

Gymbal errors on gyros is caused by?

Not knowing the other options its a bit hard to answer but Acceleration would cause an error in the gymbals the reason I say this is because ANDS (Accelerate North Decelerate South).

Precession also causes gymbal errors, hence every 15mins you have to correct your DI

4.Autopilot inputs:

Modern jets now use ADIRU (Air data inertial reference units) which combines ADC and IRS. Im not really sure what the answer would be so I cant really help you but I would of put all of them.
My reasons, if you loose your ADC you will loose your instruments hence you wont be able to use your A/P, MCP is what controls the A/P modes, ILS is the navigation side of A/P and so is the IRS.

Correct me if Im wrong in thinking that.

Nearly There
8th Dec 2009, 11:54
Punk666, ANDS refers to the magnetic compass.

annita
8th Dec 2009, 11:59
Correct, ANDS is not for gyros so Ibelieve the slow precession on the horizontal axis was correct.
Regarding the ADC, it feed the inertial unit and that was one of the answers there so I believe it was a trick question to see if you do understand that ADC outputs feed the AP but not directly.

punk666
8th Dec 2009, 14:36
Guys you are right ANDS does refer to the compass my bad. I look like a dick now haha. Precession on the other hand does cause gymbal error.

when you do a 180 turn you will notice that the attitude indicator will pitch up and if i remember correctly turn in the opposite way.

Sjclarke
8th Dec 2009, 15:03
Hi


I had the same exam questions today and the above questions got me aswell.

I have had a quick look through my book and as far as i can see the the ADC does have an input into the Autopilot

Anyway i hope we have both passed...

annita
8th Dec 2009, 15:05
Hope you did well also.

User_Irish88
8th Dec 2009, 16:17
Hey also finished the instruments exam today, and came accross some questions that i have not seen before, the first as mentioned before was to do with the gimballing error which i selected the answer with imperfections in the building of the gyro. also another one which i didn't come across before was when turning from south west to south east, what heading shall you roll out on? i selected 115 degrees for this one. other than that i think all the other questions were the same as in the databases.

annita
8th Dec 2009, 16:50
The 115 is correct I believe as you are turning away from the closest pole so its lively.
Regarding the other answer you went for,it went through my mind but then I thought that the imperfections would be considered a real wander where the gymbaling problem is cause by the gymbal axis been at 90 degrees from each other in a bank and thought that been at 90 degrees out from each other , would cause the horizontal axis, after been located at the vertical due to the bank, to precess slower.
Correct me if I am wrong.

Any comments regarding the fuel float question?