• IFR Training Part 4

    IFR Training Part 4

    By Chris Liddell

    As I signed off at the end of my last article you may recall that I was sitting on the flight deck of a British Airways Embraer jet at London City Airport!

    Getting back to my instrument training, I had relocated to Prestwick, and had begun to get my ILS approaches up to some sort of acceptable level. Just to complicate my life, my instructor introduced me to the NDB. One of the earliest forms of radio navigation the Non Directional Beacon (NDB) is a ground based radio beacon which emits a signal in all directions. The signal is shown in the aircraft on the automatic direction finder (ADF). It operates on low/medium frequency bands, and can be subject to various possible issues such as turning error, costal/mountain effect, night effect, and thunderstorm effect. In the most simple terms, the ADF needle always points towards the NDB, but in practical usage it's not always as easy as that...

    My flight simming experience had in some ways prepared me for VOR/ILS work, but I really hadn't given much thought to using the NDB, and found this part of the course to be quite challenging. My ground school book devotes 77 pages to the NDB and associated issues!

    In Scotland there are still quite a lot of NDB approaches, and ILS approaches which come off holds based on NDBs, so it's a subject that is still very relevant, despite the introduction of GPS based navigation. At Prestwick, there is an on field NDB, which is factored into a number of instrument procedures. Up to this point we had either got radar vectors, or self vectored onto the ILS approach, but we now switched to doing the whole procedure properly which involves NDB tracking.


    Flying overhead the NDB at 4000 feet, we fly outbound on a track of 117 degrees for a distance of 12.1 miles, descending 500 feet, before turning base to intercept the localiser, and continuing on to do the ILS.

    There are a couple of different ways to track NDBs, depending on your instructor's preferred method, and indeed the equipment which you have access to in the cockpit. Although you can get fixed card ADFs, they are very rare (thankfully!) Most light aircraft I have been in have rotating card ADFs.

    IFR Training
    Rotatable card ADF

    If you are really lucky - you may find an RMI (radio magnetic indicator) in your cockpit (this is like a rotating card which automatically aligns itself with the heading of the aircraft). If you use a fixed card ADF, North will always be showing at the 12 o'clock position, and in order to work out what track or bearing you are on, various mental maths is required. Indeed some people who have rotating card ADFs just set the dial as just described, and leave it there. My instructor has me use the rotating card, requiring me to keep it aligned with the DG (directional gyro) after every change of heading, so when I am intercepting a track, I have to align the ADF with the DG, then see where the head/tail of the needle sits, allowing me see what actual track I am on. Although it requires more work, the benefit is that you don't need the mental maths! 'Push the head and pull the tail' is the formula here, and it takes a while to get this into my head! What this means is, that if you are tracking towards the NDB (with the head of the needle pointing up) and you want the head to move to the right to get on the desired track, you need to turn left to 'push' it over. If you are tracking outbound from the NDB (head of the needle pointing down) and you want to move the tail of the needle to the right, you have to turn right to 'pull' it over.

    Sounds confusing? - well it is, although once you get into the air and actually do it, it makes a lot more sense! As mentioned before - these articles are not instructional in nature, and given that the NDB and its use is complicated, I would recommend you make use of the many excellent 'how to' articles and videos available. As you can imagine, my workload in the cockpit is steadily increasing, and I think most would agree that single pilot IFR can be one of the most difficult things to do. Like most skills, you can build your stamina and ability with practice, and I do feel that I am steadily improving. Things are going well, and I am beginning to move towards the end of the course. In order to achieve the IMC rating, as well as the practical test, I need to pass a written test, and the scope of what I can be tested on is pretty large. To quote the syllabus:

    "Theoretical knowledge

    The syllabus should cover the revision or explanation of:
    (1)Physiological Factors, eg 'the leans';
    (2)Flight Instruments (gyroscopic and pressure);
    (3)Aeronautical Information Service -NOTAMS, UK AIP, AICs
    (4)Flight Planning -Meteorology, Altimetry, Terrain clearance, Radio aids, the 'approach ban';(5)Instrument approach plates (Jeppesen and Aerad, as appropriate);
    (6)Radar approach procedures;
    (7)Privileges of the UK IR(r)Rating
    (8) Radio navigation principles;
    (9)Planning and use of safety altitude;
    (10) Danger from icing conditions, avoidance and escape manoeuvres."

    In other words - rather a lot!

    IFR Training
    A little light reading...

    I hit the books, and find a handy phone app which generates sample questions for the test.

    Having said that - the actual information about what the IMC written test contains is quite sketchy, so I have to cover all possible bases, checking various flying forums, and get down to reading a lot of material from the PPL course.

    1. MAD1's Avatar
      MAD1 -
      Whilst I've been focusing on the forums, the articles are excellant. Good 'bedside reading'. Will read all these but am starting at the start, 'because it's a very good place to start', and am now reading 'Going Solo' posted 13 Oct 2010, then will work my way through the series back to this current article.
    1. aikichris's Avatar
      aikichris -
      Thanks very much - I hope you enjoy the series of articles!
      Look out for the final instalment of this series shortly.....
  • Recent Forum Activity


    RAZBAM Metroliner III Causes FSX Crash

    Thread Starter: MetroAir1721

    Hello, I recently bought and installed directly from the RAZBAM website store. I installed it just as I have all my other downloaded airplanes;...

    Last Post By: mrzippy Today, 08:24 AM Go to last post

    problem with taxiing dc-3

    Thread Starter: darrenvox

    Since now i have the dc-3 back, thats great but my other worry is that its almost impossible to taxi in the dc-3. trying to taxi in the dc-3 its very...

    Last Post By: tatest Today, 06:16 AM Go to last post

    Fiat G12 CA

    Thread Starter: ColR1948

    An old bird from Italy, the Fiat GA12 CA, there are more versions to come of the G12, I know Jan already has them so he may post his collection. ...

    Last Post By: Bwoinbeerr Today, 04:43 AM Go to last post

    Out oF Memory surprise

    Thread Starter: hjwalter

    After many years of a smooth running FS9 (Win7 64bit, 2x500Gb SSDs in RAID 0, 32Gb RAM) with very many addons and still counting, I very unexpectedly...

    Last Post By: ColR1948 Today, 03:01 AM Go to last post