IMC Rating Theory

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The UK PPL IMC Rating is quite an old qualification, having been introduced sometime around the late 1960’s. Little seems to have changed. It relies on older navigation instruments rather than GPS, but perhaps this is a good thing because GPS can fail. I’ve had this happen a long time ago on a sailing trip across the English Channel, falling back on dead-reckoning and the Mark 1 eyeball to pick out the Isle of Wight in very hazy conditions.

With an intensive practical flying course booked up to begin at Easter, I thought I’d try to make progress on the theory so I’m well prepared. Anything to cut down on wasting precious flying hours usually has a good payback.

IMC Books

The standard reference book seems to be the Trevor Thom Book 5, which covers both Night Flying and IMC. The technique I used for PPL theory was to read through the book front to back first, then read each chapter again but this time testing myself on the Q&A exercises each time. This highlights the areas that have gone in and those needing a bit of refresher/reread. Then I move on to use whatever test questions I can find – for PPL I used the Oxford PPL confuser, a PC based online question bank, together with some of the Great Circle iPhone app.

For IMC theory tests, the The IMC Rating Question and Answer Simplifier (Pilots Guide)"" by Jeremy Pratt and Philip Matthews was still available from Amazon – despite being last updated in 2000 it’s still very much appropriate for the current questions. The book is really just a collection of IMC exam test papers, which you can take to simulate the real exam. I’ll probably be quite informal with the first one, to establish the level and how much further revision is required, then move on to do them more formally to a set time in one session.

Other books I’ve read that have helped include Barry Schiff’s Proficient Pilot,  despite being written from a US viewpoint, it has widely applicable common sense and includes some hints and tips for Instrument Flight. The section on working out how to enter holding patterns seemed particularly relevant.


Many instructors have commented that while flight simulators have a role to play, they don’t really give a true feeling of the control inputs or behaviour of airplanes. This is particularly aimed at those learning towards the basic PPL.

Where they do come into their own is learning instrument flight. They faithfully show exactly what the VOR, ADF and other instruments should indicate as you traverse the sky. They can be used to simulate closely what an instrument approach, cross country navigation or holding pattern looks like – and all at a fraction of the price of real flight. Several pilots have suggested that spending an hour or two getting your head around NDB holds on your computer for example is much cheaper than doing this in the air.

There are two mainstream flight simulators on the market today: Microsoft Flight Simulator (MSFS)and X-Plane. Future development of MSFS has ceased and the team abandoned, but that doesn’t stop the existing released versions from working or being enhanded by third parties. X-Plane runs on both PCs and Macs and makes a big play that their modelling of how wings behave in flight is extremely accurate and realistic.

I already had a copy of MSFS from 2003 and have been impressed with the comprehensive nature of the package. It includes a series of lessons and tutorials featuring reknowned instructors such as Martha King and Rod Machado. These include a section on Instrument Flight, including ILS let down and interpreting charts. Whilst by no means a complete alternative to the formal theory, I found these very helpful in making the step from a textbook to illustrating what it might look or feel like. Rather than just use a joystick, I’ve also bought a Yoke and rudder pedals (they were going cheap on E-Bay at the time), which add some realism and give further controls to use such as flaps and throttle.

I tried X-Plane, which runs natively on my iMac, but frankly didn’t get on with it so well. Although it comes with extensive scenery and aircraft models, it lacks some of the complementary aspects built into MSFS. For example, when connecting my Yoke, I had to manually open a configuration screen and work out which settings to use – MSFS knew the device and just automatically set it up. Since there are really only two or three mainstream Yoke products on the market, I would have thought this would be a simple thing to resolve. There are no built in lessons or tutorials on X-Plane – a link to a helpful but clearly amateur site gave some basic instruction, but nothing compared to what MSFS had offered.

The third software product I’ve tried is called RANT XL from Oddsoft. It’s a specific program designed exclusively for Instrument flight training, both IMC and IR. There is no need for a joystick – it’s not trying to teach you how to fly the plan – but there are realistic displays of the navigation instruments (VOR, ADF, DME etc.), and a few buttons to start/stop turns, climbs and descents. A series of menus guides you first through explanation of each instrument, then a series of tutorials to familiarise with their operation, then a further series of exercises for different procedures. This seems very useful when concentrating on the navigation part of the course. It comes highly rated by IMC/IR pilots on various forums.


I’m not sure if there are any restrictions on when you can take the theory exam itself. I expect it will all make a bit more sense when I’ve done some of the practical course itself. As before, I’d like to make sure I’ve completed the practice papers and am getting a high score before committing to the test itself.

Probably doing this at the club either during a cancelled slot when the weather isn’t good enough to fly might be best.

I’m expecting my brain to be quite confuzzled by the practical training sessions themselves, and will need it to be fairly clear for the exam.

But hopefully get this done at some point over the next couple of weeks.

UPDATE: I sat the test on my second day of practical IMC training and passed. Phew.

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