Finishing off the IMC course
Today was hopefully to be the last IMC training flight. I needed a further 1 hour 40 minutes of dual instruction to complete the minimum 15 hours required. Of this 10 hours must be “under the hood”, which I’d already satisfied. I’d also passed the theory test in April.
Wind blowing the wrong way
The wind from the North East meant that runway 06 was in use. The ILS is only fitted for 24, meaning that we’d be flying against the traffic flow if we used it. Fortunately the airfield was fairly quiet, with only one other club aircraft practicing aeros in the overhead – well above where we would be flying – and would finish shortly after we departed. This meant that ATC was able to offer us the use of the ILS on 24, so we took advantage of that early in the sortie while we could.
Our departure was an IFR SID – Standard Instrument Departure – which according to the plate meant that we just climbed straight ahead to 1600 feet height and asked ATC for further instructions. It seems quite strange to be told “Cleared for IFR SID Alpha departure”, but this is common for commercial IFR operations and makes you feel like you are a doing something more advanced.
A good ILS approach
The NDB procedure to the ILS went a lot better than yesterday – I had set the DI correctly for one thing, and turned more gently with a rate 1 turn followed by 30 seconds straight and level. My only big boo-boo was not turning on the carb heat early in the descent – in cloud this is even more important than normal. When we got to the 500 feet decision altitude, I took off the foggles and saw the runway slightly offset to the right where it should be.
A missed approach under the hood
I then put the foggles back on and did the missed approach procedure, climbing straight ahead and followed ATC instructions as we departed the Zone. We asked for, and were given, a deconfliction service – matching what we’d need in real IFR conditions – meaning that we needed to tell the controller when we changed height or course, and to follow directions when given. After a while, Ian requested returning to Basic service so that we could continue General Handling.
The next task was to intercept and track the Compton VOR. I’m normally pretty confident about my VOR use, but lack of practice meant that failed to spot it was 180 degrees out. Although asked to intercept the 270 radial inbound, I was of course flying about 90 degrees and should have set the VOR to that also. Given that the VOR itself was some 40 miles away, I had calculated for a 90-degree intercept and once setup correctly we made the intercept and followed it OK.
A few good acronyms and rules of thumb
Before we took off, Ian had briefed me about the STIFQWM acronym (pronounced Stiff Kwim)– a new one for me – which he reminded me about several times during the sortie. It’s used to check that each nav instrument is working and setup correctly:
Select, Tune, Identify, Flags (i.e. are the warning flags showing, to/from flags as expected), QDM (set the bearing if required), Wind (taking into account drift angle) and Marker (middle and inner marker alerts, rarely used these days).
Two good rules of thumb helpful during procedural approaches were:
Max drift = windspeed/groundspeed in nautical miles per minute
e.g. 20 knot windspeed at 90 knot aircraft speed = 20 / 1.5 = 14
Then calculate what proportion of that max drift applies, so for 30 degrees off the runway would be ½ = 7 degrees.
Rate of descent required = groundspeed in knots x 5
So if groundspeed is 90, then descend at 450 feet per minute
e.g. flying at an airspeed of 90 knots with a headwind of 20 = 70 x5 = 350
I got a dose of the leans
We repeated a number of unusual positions, recovering both under full and partial panel plus some height keeping practice before returning back to the airfield for an NDB approach to 06 with a low level circuit to land.
Whether these exercises were a bit more dramatic than before, or we did more of them, I felt more disorientated than before. My body was telling me I was in quite a different position from what the instruments were saying. In these cases, you really have to trust the instruments. This is the first time I’ve really noticed this effect fully – called “the leans” because you think you are leaning one way but actually are somewhere else.
Inbound for an NDB hold and approach
From the direction we were coming from, which wasn’t within the 30 degree arc of the outbound course, we needed to do a hold. The first didn’t go so well, so we did a second. You can be sure I double checked the DI matched the compass and carb heat was on as we started the descent.
Ian had switched off the DME so we had to rely on timing with the stopwatch to determine the right time to turn back to the field. With something like a 20 knot wind behind us, I assumed a ground speed of 120 knots and thus 4 minutes before starting the turn. This approach went better than my last NDB one, perhaps more through luck than judgement, and I felt a little wary because of not knowing how far away the airfield really was. I could check the direction with the ADF, but not the distance to go (because the DME was switched off).
At the minimum decision height of 600 feet, I took off the foggles and was relieved to be able to see the runway where it should have been.
Low level circuit with flaps
I then configured the aircraft for a slow low level circuit, turning left about half way down the runway and keeping it relatively close to hand. I’d put in two stages of flap so could confidently fly slowly using gentle turns, with full flap on final and touched down fairly gently.
The debrief listed many of the points I’d already recognised. During this flight, and particularly during the approach procedures, Ian had left the radio and decision making much more to me than before. This both gave me more confidence that I was learning what was required as well as reinforcing many of the learning points.
Ready for test
With the hours completed and paperwork done, my next step is to try and arrange a test with the club examiner. Hopefully this can be done later this month, while the facilities remain available to us at Lyneham.
My thanks to the several instructors who have taken me through the IMC course at Lyneham. I’m very fortunate to be able to do this here and am pleased to be able to complete it before it closes. The wide range of approaches, ATC services and choice of runways will be sorely missed.
I’ve taken the IMC course perhaps a bit early in my flying career because I wanted to take advantage of Lyneham while I still could. Perhaps it would have been better to build up some more solo hours and experience first – I seem to have done a lot of different additional training since I passed my PPL, and hopefully can now concentrate on putting this into practice and gaining more proficiency and experience. My next step will be to do that over the summer. I’ve arranged for a few trips in the coming month with various passengers and also hope to visit one or two other new airfields.
Time this flight: 2:00 Dual
Total IMC Training: 15:20
Total Time: 109:05
Total PIC Time: 34:00