South Asia and Far East WannabesA forum for those applying to Cathay Pacific, Dragonair or any other Hong Kong-based airline or operator. Use this area for both Direct Entry Pilot and Cadet-scheme queries.
When accelerating on a westerly heading in the NH, the compass card of a direct reading compass will turn: a.Clockwise giving an apparent turn towards south b.Clockwise giving an apparent turn towards north c.Anticlockwise giving an apparent turn towards south d.Anticlockwise giving an apparent turn towards north
I opted option b but apparently, its D. I'm guessing the logic here would be just figure out which direction the compass would turn (ie., accelerate west , northern hemisphere compass appears to turn clockwise and read higher than actual) and then reverse the answer for the compass card. Any inputs?
This question is concerned with the effects of acceleration on a direct reading magnetic compass. These effects depend upon the magnetic latitude, the direction of flight and the acceleration rate.
The lines of force produced by the earths magnetic field flow vertically upwards, out of the ground at the magnetic south pole and vertically into the ground at the magnetic north pole. The degree to which they are inclined vertically at all other points on the earth is determined by the magnetic latitude. At the magnetic equator they are horizontal or parallel with the surface. As magnetic latitudes increase towards the magnetic poles the degree of inclination also increases. The inclination of the lines of force causes the magnets in compasses to dip below the horizontal, thereby reducing their accuracy.
In order to minimise this problem, compasses are typically suspended such that their C of G is lower than their pivot. In this way the weight of the magnet is made to oppose the dipping caused by the lines of magnetic force. This is termed pendulous suspension. Although this reduces compass dip, it does not entirely eliminate it. This means that the C of G of the compass magnet will be off-set to one side of the pivot such that the C of G moves away from the nearest pole. This means that the suspension point is between the nearest pole and the C of G of the magnet.
Whenever an aircraft accelerates or decelerates on heading other than due north or due south, the lateral displacement of the C of G and the inertia its compass magnet, causes the magnet to rotate. The magnitude and direction of this rotation is determined by the aircraft heading, the hemisphere and the acceleration or deceleration rate.
This question specifies acceleration on a westerly heading in the northern hemisphere. This will cause the compass magnet to rotate anti-clockwise. The compass magnet is fixed to the compass card, so the compass indication will increase. This will indicate a turn to the north. This answer illustrates the more general result that accelerations cause an apparent turn towards the nearest pole. Decelerations will have the opposite effect, producing an apparent turn away from the nearest pole.
yes,the answer is D.Because, in the NH when the a/c accelerates it Over reads i.e. it will read more than 270degrees and the compass card moves in anticlockwise direction.So, Anticlockwise and apparent turn towards NORTH make sense.
@KW - true, i remember reading this in oxford/gsp.. however, there's no mention of the magnetic card moving in the dir opp to the compass. ie., if as you say, the compass is fixed to the compass card, doesnt that make my answer correct (b) rather than (d)?
The card has the 360 degrees marked on it. This is connected to the compass magnet, such that under steady state conditions the 360/000 mark aligns with magnetic north.
The kind of compass that we are talking about does not have a moving needle. Instead it has a fixed mark that is aligned with the nose of the aircraft.
So if the card moves anticlockwise the indication increases.
In this question the aircraft is heading west so the needle is intially pointing at 270.
When the card rotates anticlockise this increases the degree markings that line up with the needle. In reality the needle and the aircraft nose are still pointing to the west, but the heading indication has increased. So it looks like heading is increasing towards the north.
Last edited by keith williams; 7th Aug 2012 at 22:49.
The link below covers the subject of direct reading magnetic compasses and compass errors.
But take care in using it.....it was written in Australia so it is for the southern hemisphere. The effects are all reversed in the northern hemisphere.
CompassesThe north magnetic pole is situated in Northern Canada, and the south magnetic pole in Victorialand, in Antarctica. Direct Reading Compass. Fig 1. Fig 2. avfacts.com.au/sample/navinst2a.PDF - related
I have a Indian DGCA CPL License with a Multi Endorsement. I had converted my FAA CPL to an Indian DGCA CPL. I am NOT working with any airline currently.
I would like to appear for the Written Exams held for the ATPL in the Oct 2012 session.
I know this question has been asked before, but I would like to be diligent, and confirm - what are the subjects that I should study, for the ATPL exam?
According to the CAR, Date 16th June, 2011 Syllabus for Examination for Issue of Airline Transport Pilot's License - Aeroplanes, the subjects are -
- Air Navigation
- Aviation Meterology
- Radio Aids and Instruments (Avionics)
- Air Regulation
- Aircraft and Engines - Technical General
- Technical Specific Paper
- Techincal Performance Paper
- Radio Telephony
I understand, that the Technical Specific Paper & Technical Performance Paper are probably specific to the plane that I will gain my 1500 hours of experience on. (Not sure, just guessing)
I not too sure what the deal with the Radio Telephony subject is considering I possess the FRTOL license.
Here's were I have my doubt - Do I have to appear for the Air Regulation subject & Aircraft and Engines - Technical General subject examinations?
If not, Why?
Can anyone provide me with this information, and also back up the information with a DGCA website link if possible? I have tried looking for information on the DGCA website, but my efforts were futile.
Also, Is there a phone number of a person in the DGCA I can talk to regarding this information?
Any answers, you could provide will be really helpful. Again I would like to say that I know this question has been asked before, but as you'll know any information regarding the DGCA is so difficult to obtain, & I would just like to be clear.
For the Subjects Air Nav and Radio Aids you have to give and oral . You have to obtain 70% in both the written and oral exam to be considered as passed .
For eg : If you get 90/90 in the written exam and 6/10 in the oral exam for a total of 96/100 you will be considered failed because you need a min 7/10 in the orals .
Once you pass the written exam you will have 3 attempts at passing the oral exam . If you dont pass in 3 attempts you will have to give the written exam allover again .
After you pass the written exam they will automatically schedule you for the oral exam . If you dont appear for it , then they will count that as a failed attempt and subtract it from the 3 attempts for the oral exam .
From then on you can schedule your oral exam anytime you please . But you will have to pass the oral exam within 24 or 30 months ( not sure ) from the date of passing the written exam . Otherwise you will have to give the written exam again .
Last edited by cyrilroy21; 19th Aug 2012 at 09:51.
a reply to all those who pm'd me. If you are in Delhi,for printout at real cheap rates,go to nehru place there is this shop opposite sona sweets,cant remember the name.you will need to search a bit.its a sardar uncles shop.just tell him you need the printouts and bargain a bit ,tell him three of my friends have already come and got the prints.he will reduce the rate.in any case it should not be more than .6 to .7 rs per page.dont remember exactly though.just dont forget to bargain..comes out pretty cheap!
i passed ATPL written + oral exam, i am planing to move out of country for job search. since result card distribution was stopped by DGCA, what document can i carry along as a proof for my ATPL exam result, i believe just result printout will not be enough. on special request will DGCA give any official letter stating my result? any other suggestions are appreciated
Hey guys, i'm new here. Need some help please. For the ATPL Met Paper, are the questions from Oxford Met & IC Joshi books sufficient (approx 1000 qts in total) or are the questions from the Keith Williams CD, subject Met (1600 qts) also required? Anyone already taken the ATPL Met exam please help. Many thanks
yeah so im pretty disappointed, I score 66 today in the met exam.. I did oxford met entirely, cpl notes probably 2-3 questions came from the Oxford back questions. The mistake I did was not study from IC joshi, I have ordered the book now. .. The paper was okay, wasnt easy.. Was definitely a little tricky.
Last edited by AviatorVette; 8th Nov 2012 at 06:17.
@AviatorVette yeah it was definitely a tricky paper. But I would disagree on the Oxford part. I felt that a majority of questions were from the oxford met book. And as for IC Joshi.. there were only 2-3 questions from there. (excluding ones about Indian Climatology. ) In my honest opinion, if I would've studied only IC Joshi and not oxford.. I would've done miserably.