By Chris Liddell
I would like to begin this article by making it clear that this series is in no way intended as instructional material. The intention is to give a (hopefully) interesting account of my instrument training experience. I am not an instructor, and have done my best to give accurate information on the topics covered. If there are any errors I apologise!
Having decided to train for an instrument rating, I have a couple of options open to me. Outside the UK the only option (as far as I am aware) is to train for a full ICAO Instrument rating. In the UK however there is also the IMC rating. IMC stands for 'instrument meteorological conditions' - the opposite of VMC 'visual meteorological conditions'. This rating is now officially known as the IR(r) or restricted instrument rating, but for the purposes of this article will be referred to as the IMC rating!
A full IR requires a minimum 50-55 hours training (depending on whether it is a single or multi engine rating) of which 20-25 can be logged in an approved simulator.
The IMC rating requires a minimum 15 hours of training of which 2 can be logged in an approved simulator. Both ratings have a theory component with written exams plus flight test.
Obviously if you have the ambition to become a commercial pilot, or own a capable touring aircraft which will be used to fly on business, and other long trips flown under Instrument Flight Rules, then the full IR is the obvious choice.
As a leisure pilot, who hires from a flying club, the IMC rating makes the most sense. Given the sort of flying I do and the large cost to do a full IR, the IMC rating will serve my purposes well.
'Jim' who will instruct me through this course (see part one of this series) is well qualified with single/multi engine, instrument and seaplane instructor privileges, as well as being a CAA examiner. I arrange to begin my training, and with a sense of excitement go to Glasgow International Airport to begin the IMC course!
To quote the introduction of the IR(r) syllabus:
'The aim of the Instrument Rating (restricted) course is to teach the student basic and applied instrument flying as set down in CAA Standards Document 25(A). It will give the student a sound knowledge of aeroplane single pilot IFR operations in UK airspace. The course is designed to meet the requirements of Part 2, Chapter 1, Section 2 of the UK ANO, specifically: to entitle the holder of the licence to act as pilot in command or co-pilot of an aeroplane flying under the Instrument Flight Rules except (a) in Class A airspace; or (b) when the aeroplane is taking off or landing at any place if the flight visibility below cloud is less than 1,500 metres.'
It should be noted that the IMC rating is a UK only rating, and has some limitations on it (hence the 'restricted' bit) - these will be clarified later in this series.
We begin every lesson with a thorough briefing, including a detailed weather assessment which includes checking the freezing level, cloud bases/types, MSA (minimum safe altitude) for our route, alternate airports, and a discussion about the content of that particular flight.
The first part of the course is attitude flying, and basic instrument flying.
Instrument training requires the student to have their vision of the outside world limited to simulate flying in cloud and there are three options here - screens, foggles, or hood. Not many light aircraft have screens fitted, and I wear glasses which makes foggles a bit awkward, so I opt for the hood.
Glasgow Airport is a bit of a culture shock for me! - you may recall from my 'Going Solo' articles that my training was done at Cumbernauld Airport, which is in uncontrolled airspace, and uses an A/G (air to ground) radio which is the most basic ATC service available in the UK. Flying in and out of an International Airport requires copying ATIS, communicating with ground, tower, and approach controllers, and departure clearances - all within class D airspace. Sequencing between commercial flights (anything from light twins up to and including A380s) and wake turbulence adds to the fun!
Pre flight and ground checks are similar to my normal visual flying, but with added emphasis on equipment vital to IFR flight, such as the vacuum pump and pitot heater, and checking for the correct operation of the directional gyro, turn co-ordinator and attitude indicator during taxiing.
At the heart of instrument flying lies the ability to fly headings and altitudes accurately, and the first part of the course addresses this.
Basically it's like learning to fly all over again, as I work through all the basic VFR manoeuvrers but this time without being able to see outside! Straight and level, turns, climbs and descents are covered, and it's challenging to begin with. I am taught instrument scans, and how to use the AI (attitude indicator), ASI (airspeed indicator), DG (directional gyro/compass) turn coordinator, altimeter, and VSI (vertical speed indicator) to cross check and verify how the aircraft is flying. I also revise how these instruments work, particularly in relation to possible failures and limitations of use. The vast horizon of visual flying is now condensed into the small AI and it's amazing how subtle adjustments can make significant changes to the flight path. The dot which separates the upper and lower halves of the AI is small but sometimes it's necessary to raise or lower the nose of the aircraft by half of that dot!
Smooth accurate flying is the aim, and all heading changes have to be achieved through rate one turns.
A rate one turn is 3 degrees/second and will change the heading by 180 degrees every minute, so two minutes at rate one will achieve 360 degrees etc. Turning too steeply in non visual conditions is a sure way to lose control of the aircraft, so subtle, gentle changes are the best way. A rate one turn is judged either by using the 'rate one' mark on the turn coordinator, or using a specific bank angle - calculated using the true airspeed of the aircraft being used (about 17 degrees on most light aircraft) The first couple of lessons are spent working on attitude flying, following heading and altitude changes as per my instructor's direction. Much of this can be achieved by knowing your aircraft - the mantra is 'power plus attitude = performance' - in other words when using a particular power setting combined with a predetermined attitude (nose up/down, bank angle), you will always get a consistent result.
As well as doing this, I still have to keep up with all the normal checks of visual flying, such as FREDA checks (fuel, radios, engine instruments, directional gyro alignment, and altimeters) plus ATC interactions, and after take off/before landing checks. It's so easy to lose track of your assigned altitude/heading when doing additional tasks, and on most flights, by the time I get 30/40 minutes in, I become totally maxed out. It's an old joke, but it's very true to say that if at a certain point, ATC asked for your name, you would have to reply 'standby...'!
The basics are coming together, and I soon start to work on unusual attitude recoveries.
Yet again these are basically the same as taught for visual flight, but still of course in simulated IMC. Recovery from a steep descending turn, and from a steep climbing turn are covered, before moving onto the next part of the syllabus which is limited panel work. Two of the primary instruments used in non visual flying are the attitude indicator and directional gyro. Both these instruments are powered by the vacuum pump, and the suction created by this pump is displayed in the cockpit on the relevant gauge.
Should this pump fail in IMC it is considered an event which requires a pan-pan call to be made. Both AI and DG will stop working, and the other remaining instruments will need to be used to control the aircraft's flight path. The scan changes to take in the turn coordinator, airspeed indicator, altimeter, and vertical speed indicator. With this limitation, I have to learn to perform straight and level, climbs and descents, and turns onto given headings. The directional gyro is normally used to verify heading, but of course this is now not available, so the compass has to be used. I am shown the limitations of the magnetic compass, and it's really complicated. The compass is only reliable in stable straight and level flight, because during any manoeuvres it jiggles and jumps about and depending on the direction of the turns it will over/undershoot, and is also affected by acceleration/deceleration. This is a complicated subject, with 13 pages of information devoted to it in one of my text books!
Thankfully there is an easier method to be used and it is the 'timed turn'. You will recall that instrument flying makes use of the rate one turn. As this equals three degrees/second, this can be used to work out how long you need to be in a turn to achieve a specific heading. If we are on a heading of say 060 degrees, and are asked to turn to 180 degrees that is a difference of 120 degrees. 120 divided by 3 is 40 - so we do a rate one turn (to the right!) for 40 seconds and should find that we roll out onto our new heading.
In case you are wondering how the vacuum pump failure is simulated - well it is achieved by the high tech 'bit of paper' which is used to cover up the AI and DG!
The final part of my limited panel work is more unusual attitudes, and this is tricky as the working instruments are few, and learn to deal with recovering from a sustained 45 degree banked turn, a steep descending turn (the infamous spiral dive/graveyard spiral), and recovery from the approach to stall. This is about as hard as it gets, and taxes what limited brain power I have! Limited panel is a very serious situation, and a former work colleague lost a close friend in an accident, which was caused by a pilot losing control in cloud, due to a vacuum pump failure which caused the loss of the attitude indicator.
Having now covered all the syllabus for attitude/instrument flying in about five hours tuition, Jim my instructor draws the initial phase to a close, by having me performing the SRA, as a practical demonstration of basic instrument flying skills.
SRA stands for 'surveillance radar approach' and is the classic ATC 'talk down' procedure.
We position about 10 miles from Glasgow, and ask the radar controller for the SRA procedure. Most ATC units are happy to accommodate this (workload permitting) as they need to keep in currency with this procedure themselves.
I am given a series of vectors (headings and altitudes) and by following them I end up with a large runway ahead of me and go on to make a visual landing! I have to say that even if I had stopped my IMC training at this point, I would have already succeeded in gaining a life saving skill. The SRA has saved more than a few pilots who have declared a mayday, and have been guided down to the runway. In theory any PPL should be able to do this, but given the limited amount of instrument flying given during the PPL course it would be difficult, so I am happy that I have already upped my game as far as my ability to fly using instruments alone.
The SRA feels very real (well - it is the real thing!) as I am being given all my instructions via ATC rather than my instructor who is sitting beside me, so at the end of this flight I really feel I have achieved a milestone in my instrument flying journey!
The next part of the course will be moving onto 'applied instrument flying' which includes radio navigation - the first topic on the list being the VOR.
My next article will describe my continued progress through the IMC course.
Watch this space - happy simming!
There are no comments to display.
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!Register a new account
Already have an account? Sign in here.Sign In Now