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How To Fly Dangerous Approaches: Innsbruck, Austria

 

How To Fly Dangerous Approaches: Innsbruck, Austria

By Andrew Herd

 

 

 

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Click LOWIunl.pdf to get large size PDF image

 

 

Navigational equipment required:

Standard basic avionics fit plus VOR indicator, DME, and ADF.

 

Aircraft:

This tutorial can be flown with the Microsoft Lear and I have included situations for that aircraft. If you are unfamiliar with the flight parameters for the aircraft I have included a crib sheet for the Lear here. The Microsoft .air file for this plane is not one of their better efforts and I would recommend using Steve Small's .air file if you want the aircraft to fly anything like the real thing. The other thing that I must warn you about on the Lear is that whoever did the panel forgot to put the autothrottle on it. Yeah, I know, hilarious, good job Microsoft don't make real planes, is it not? This means that you will have to ensure that the autothrottle arm is checked by going to the menu and visiting \aircraft\autopilot.

 

Note that in the situations, the fuel load has been cut to about 25% for the sake of realism, which will allow you to land without using up the entire runway.

 

Scenery:

I used the Innsbruck airport from Aerosoft's excellent German Airports 1 payware package and Eddie Denney's RealSceneFS mesh. There are various freeware versions of Innsbruck around on this web site which are worth a go if you don't have German Airports 1, and Eddie's mesh isn't the only one available for this area, so shop around and use something else if you prefer - but I would recommend using a mesh add-on as the approach will make more sense if all the mountains are actually there!

 

The one thing you must do is to download Andreas Widmann's Innsbruck navaids correction (lowioej.zip) which is available here on FlightSim.Com. Without it, you will be missing most of the rather complex localiser setup that Innsbruck possesses - it isn't there in the default scenery. Andreas has implemented the localiser as a VOR, but it is correct that it lacks a glideslope. If you don't install it, then parts of this tutorial will not make much sense.

 

Downloads:

INNSBRUCK_APPROACH.ZIP - extract these files into your \FS2000\pilots folder

 

Comments:

The tutorial assumes that you understand the basics of VOR and NDB navigation and that you know the basics of how to fly an ILS. I am assuming that you have flown the earlier approaches in this series and have learned the techniques explained there.

 

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Innsbruck must be one of the most beautiful airports in the world, but it isn't in the most convenient place. The runway is at an elevation of 1900 feet and the final approach has to be made in a narrow valley with enormous mountains on either side. The descents are steep, at over 400 feet per minute, the tolerances are tight, the localiser is offset five degrees, the final approach is visual and the missed approach procedure involves a steep climb followed by a terrifyingly tight turn. If this isn't enough to put you off completely, there is the added challenge of Foehn wind conditions.

 

The Foehn is special to the Alps, but similar sorts of winds occur in mountainous regions all over the world, (the Chinook in the Rockies, the Sirocco in Italy and the Khamsin in Egypt, for example.) In each case the principle is the same. When humid air reaches mountains it has to rise and it cools down in the process. Eventually the air saturates and it starts raining, which dries the air; usually when the air masses reach their highest point. Then the air begins to fall and as it does it warms up again. It doesn't sound too bad when it is put like that, but the result is a surface wind which at Innsbruck has a direction of 100-180 degrees, average windspeed of 15-22 knots, and gusts to 30-50 knots, which can make the approach fairly challenging. The notes on the approach make the admirable understatement that severe turbulence, associated with horizontal windshear, and severe downdrafts can be expected below 5000 feet, especially over the town of Innsbruck itself, which can make approaches from the west particularly tricky.

 

Take some time to study the approach plate series. Please click the top thumbnail to download the PDF file containing all the approach plates you need. Jeppesen have also allowed us to reproduce an approach plate and you can view this by clicking the lower thumbnail.

 

Instructions:

Please make sure you have Indicated Airspeed (IAS) set. If you have True Airspeed set, the instructions which follow will make no sense at all. Ensure that the EHSI and the RMI of the aircraft are aligned, which is the default situation. Also, ensure that you do not have gyro drift checked under the realism settings, unless you are proficient at making corrections for this. Do not use the GPS on pain of death. The tutorials are written for the FSS plates, but I have indicated where the Jeppesen plates differ.

 

Last of all, before we get going, if any real-world ATPL holders would like to correct me on any of this, I would be glad to hear from them.

 

Talk through

 

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Situation 1: East procedure Rwy 26 precision approach - select situation InnsbruckLearVillach1a

 

The situation places you inbound to the Rattenberg NDB at 16000 feet, with an IAS of 280. You are about 64 nm from the Villach VOR and the aircraft is in Nav hold mode. Looks good out of the window, doesn't it? Nice day and all.

 

Heh, heh.

 

Anyway, you are are planning to set your passengers down in Innsbruck very shortly, so tune in to the ATIS (126.025, welcome to European fractional frequencies - visit options, setting, instrument and click 25 khz so the radio will receive it) and get the weather report. Those of you who didn't reset the altimeter on the Aspen approach will remember to do it now - for the rest of you this is a friendly reminder.

 

Now take a look at the glass. In these winds, the aircraft is tending to stray off the airway, so it might be worth unchecking the nav hold and switching in heading hold to get back on track. Your ADF should be tuned to 303, which is RTT NDB, and the white needle should be pointing straight up if we are heading toward it, so make any alterations of course you need.

 

 

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One of the reasons for choosing this approach is that it is a good demonstration of how far commercial pilots has to anticipate - and do remember that we aren't doing any radio communications here, which adds to the workload. If you look at the STAR plate with VILLACH 1A on it, it seems as if all we have to do to align with the approach is to alter course onto approach once we reach RTT and fly straight in - but there are two reasons why we can't, which will be apparent if you study the East Procedure plate as well.

 

The first reason why we can't turn straight inbound is that to begin the approach we would need to alter course by nearly ninety degrees, which would spill everyone's drinks, not to mention being an illegal turn. The other problem is that we are at 16000 feet and the profile begins at 9500. Given that the airway we are on has a minimum enroute altitude of 15000 feet, somewhere along the line we are going to have to lose at least 5500 feet, even if we are down to the MEA at RTT. The solution is to fly around the holding pattern in order to lose height and align course, and with one minute legs, if we lose 1800 feet on each inbound and outbound leg, one turn should be enough. The one thing in our favor is that our approach angle to RTT means we can make an uncomplicated direct entry to the holding pattern. By the way, if you don't know how to fly a hold, then I recommend reading Jaques Zahar's superb tutorial on the subject, which explains everything you need to know.

 

 

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Reduce your speed to 250 knots and watch the white NDB needle - the moment it begins to swing, begin your holding pattern entry. Screen shot one shows the Lear making the first turn after crossing the NDB. Don't be in too much of a hurry to turn onto 048 - if you judge your turn so that the CDI needle is deflected about a dot and a half as you become established on the outbound course, you should be well positioned to make the distant turn of the pattern without having to tighten up too much in order to prevent an overshoot.

 

Once you are established outbound, get the instruments set up to intercept the inbound leg. The holding pattern is centered on RTT, but is aligned on the 228 radial from the Salzburg VOR, so you need to tune Nav1 to 113.80 and twist the course to 228. If you watch the EHSI on the outbound leg (one minute legs, so use a timer), you should be able to correct for wind drift by making sure your course parallels the CDI, a neat trick which cannot be done without a glass cockpit. You can descend in the turns as long as you restrict your bank angle to fifteen degrees, but beware the Lear's horrible tendency to lose height very rapidly as it is going around - you can easily end up a thousand feet too low here, which could be a fatal mistake. The solution is to set your target height to 10500 and to add quite a lot more power in the turns, being careful not to let the airspeed balloon. Dropping 8 degrees of flap won't hurt either. Screen shot 2 shows an almost perfect intercept of the inbound leg, with the aircraft coming nicely down to altitude.

 

 

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The inbound leg requires a certain amount of concentration. You must identify the OEV localiser no later than overhead the RTT NDB, so tune Nav1 to 111.1 well before you reach it. Reduce speed to 180 knots, drop 8 degrees of flap if you haven't already, and the moment the white needle swings again, indicating that you are crossing back over the NDB, which is the initial approach fix, alter course to 211 and maintain height - assuming you have the localiser - if not, you will have to go around the pattern again. Now set a course of 255 on the OBS. The object of the exercise is to allow us to identify D22 from the localiser. In these weather conditions, this is a really tricky one to get right, and I failed to do it first time too. You should be able to see the localiser on the EHSI, so if you don't intercept it exactly at D22 just fly on until you do. This is only a simulation after all - if real life you would want to do it perfectly - that is why they pay the professionals the money they do. Screen shot 3 shows the D22 intercept. When you reach this point alter course onto 255 and maintain altitude.

 

 

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Now the kind people who did the plate obviously appreciated that the cockpit workload is rather high up till now, because they allow you a short breather before making the descent, which begins at D17.2 from the localiser. At this point the reason for the D22.0 intercept becomes clear - the main problem if you overshoot RTT by a significant margin is that you can end up intercepting the localiser as close as D20, which gives you very little time to prepare for the descent; and descending from above the localiser could easily result in a controlled flight into terrain. At this point you can tune the Absam NDB on your ADF (313) as you may need it for a missed approach.

 

Once you are established inbound on the localiser course, drop 20 degrees of flap, and start reducing speed. Now the big question is what IAS we actually need here. The SAS FSS plate is optimised for a Boeing 737 and suggests a fairly high approach speed of Vref 30 + 15 until visual, which builds in a good safety margin for adverse weather conditions. Later, if you want, you can fly the approach in a 737, but I would recommend a bit of practice in a smaller aircraft first. In the Lear, I would recommend is an approach speed of 130-140 kias, which allows a similar safety margin, and so we need to need to reduce speed to 140 knots and drop 40 degrees of flap as we begin our descent at D17.5.

 

 

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Once you have the localiser, drop the gear and get on down. You will find that a rate of up to 1200 fpm is needed initially, depending on wind and turbulence, and pay very, very close attention to the altitude restrictions, because the clearance over obstacles isn't that great. The missed approach is at at D4.0 from OEV, the localiser, at 3700 feet. Screen shot 4 shows the situation at about D14 from the localiser. Depending on your luck, you should be visual fairly early on in the descent, and you can fly her in the moment you feel happy to do so.

 

When you cross the threshold, cut the thrust to idle (I would suggest that you knock out the autothrottle at about 5 nm from the localiser, or you may have trouble getting your airspeed right given the wind conditions) and get ready to deploy the spoilers on touchdown. You can let her roll to a halt with a touch of brakes, reverse thrust would be overkill.

 

Situation 2: ILSDME Rwy 26 precision approach in bad weather - select situation InnsbruckLearVillachBad

 

 

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OK, that first approach shouldn't have been too difficult if you have flown the other tutorials in this series, now let's do it in worse weather.

 

The problem in this situation is the gusting wind, which plays havoc with the autopilot and means that you have to pay extremely close attention to the airspeed and sink rate on the turns in the holding pattern. Depending on which way you are travelling, you will probably find that you need 30 more knots set on the autothrottle than you need in order to maintain a given IAS. I found I had to fly the descent with 180 knots set in the autopilot and a descent rate of 1200 feet per minute to begin with, easing to 800 feet per minute later. As you descend, be prepared to alter your descent rate if you look to be going down too fast. Once you pass RTT inbound ensure that you tune the Absam NDB on your ADF (313) as you may need it for a missed approach.

 

 

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The missed approach point is at D4.0 from OEV, the localiser, at an altitude of 3700 feet, which is the best height to set on the autopilot. There is a hell of a lot to watch out for on this approach - the wind is blowing you all over the place, so try not to stray off the localiser, and watch your height like a hawk, because going below one of the restrictions could pile you into a mountain. Too high is better than too low, believe me.

 

The critical restrictions are at D8.0 to D6.0 as at that point you are flying over a mountain with only a thousand feet to spare (screen shot 6). This is not the place to discover that you haven't reset the altimeter, and in these weather conditions it is all too easy to forget your altitude while you are fighting to keep the plane on track.

 

 

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This is, as you have probably already guessed, a missed approach. You might be visual at the MAP, but I doubt it. When you take the decision, lift the gear, knock out the autopilot, push the throttles forward and pick up your flaps to 20 degrees once the airspeed exceeds 140 knots. I can't emphasis too much that you need to climb as high as you can by the time you reach D1.0 from the localiser, and then make the sharpest turn the aircraft is capable of, because there is no room at all for executing this manoeuvre. I suggest at least a thirty degree bank, forty five if you have the airspeed, and flying the aircraft by hand on full throttle - and at the risk of repeating myself, make sure you gain all the altitude you can before doing the turn, because if you try to simultaneously climb and bank steeply a stall is almost inevitable.

 

At the NDB, lift the flaps, set 9500 altitude and a 1500 fpm climb rate, set the heading to 075 for the outbound course (if you leave the OBS set to 255, the localiser will sense normally, even though you are flying it the wrong way), reset the autothrottle, and switch the autopilot back in, if you are cool enough. This is probably the moment to say something to the passengers like, "Er, we just had a slight problem and had to go around, did any of you see the expression on the face of that bird perched on top of that cliff back there?" Once you are past Absom, tune the RTT NDB on 303 and at D14.0 on the localiser, alter course to it and enter the holding pattern using a teardrop entry. Not much fun to do that in real life, I think.

 

 

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The Jeppesen plate has an important difference from the FSS one, in that the missed approach outbound track uses the back course of the OEJ localiser, yup, there are two of the little varmints (unless you are using the default MS scenery, in which case OEJ is missing). The trouble with the Jepp plate is that it isn't very clear, and it is all too easy to fail to appreciate what is going on, especially given the single letter difference between the localiser IDs and the sheer amount of clutter on the chart. Flying the Jeppesen missed approach is much the same as flying the FSS one to begin with, except that Jeppesen put a minimum altitude constraint of 3700 feet on the climb before the turn at D1.0 OEV. You then intercept the OEJ (109.7) localiser front course on 068, and once you have passed over the beacon, fly out on the back course (hit the back course button on the dash) on 066 with maximum climb gradient until you reach 9500 feet, after which you turn left and fly direct to the RTT NDB where you hold again. One of the disadvantages of this procedure is that at the very moment you need all the help you can get you are very close to the localiser, with the needle is so sensitive it isn't much good, though to be fair, this is partly down to the way the localiser has been implemented as a VOR in the fix.

 

Situation 3: West procedure Rwy 26 precision approach - select situation InnsbruckLearWest

 

If you have got this far, I consider you to be an experienced pilot, so no more Mr. Nice Guy. We are now going to fly the west procedure, which is one of the most difficult ones in existence. I suggest that anyone who needs to empty their bladder does so now, to save embarrassment later. By the way, the screen shots show much better visibility than you are going to get. I thought you might like to see the mountains just once.

 

 

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The situation places you about 18 nm outbound from the KPT VOR at 13000 feet, the MEA for this transition. Nav1 is tuned to KPT on 109.6 and the ADF to 413, which is the KTI NDB, which is the IAF. You will reach KTI when the DME reads 42 nm from KPT, so sit back and enjoy the view for the time being. At about 35 nm DME, reduce your IAS to 250 knots and prepare for the turn.

 

At about 41 DME, alter your heading onto 104 degrees, retune Nav1 to the OEJ localiser on 109.7 and twist the OBS to 068, your inbound heading. Reset your altitude to 11500, with a sink rate of 1500 fpm and once you have made the turn, reduce your IAS to 180 knots and drop eight degrees of flap. Unless you have eight pairs of hand, use of the pause key might be appropriate here. According to the procedure, the OEJ LLZ/DME must be identified not later than overhead the KTI NDB and with Andreas' fix applied this is exactly what happens, as shown in screen shot 8 - see the white ADF needle falling.

 

 

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Looking at the plate, you should intercept the localiser at D20.0 at 11500 feet. As the CDI begins to center, alter your heading to 068, reset your altitude to 5000 feet with a descent rate of 1000 fpm, and once you have the localiser, drop your gear and reduce speed to 140 IAS with 40 degrees of flap. This should allow you to make the altitude restrictions without any problems - just make sure that you don't get so obsessed with playing around with the descent rate that you wander off the localiser!

 

The MAP is at D6.0 at 5000 feet, at which point you have actually crossed Innsbruck and must conduct a visual approach after making a tight right hand turn assuming you are VFR. I would recommend flying this one by hand, because once again, there isn't a lot of room to get around, and the autopilot is unlikely to manage it. This turn is very problematic: if you make it too wide, then you will have trouble establishing yourself on finals; too tight and you may not have the airspeed to get around. I chose a bank angle of between 30 and 45 degrees and had just enough room to get in. In real life, this one would be very sweaty first time. Not to mention twentieth time - it is bad enough in Flight Simulator. By the way, you did remember to contact ATIS and reset the altimeter, didn't you?

 

Andrew Herd
andrew@flightsim.com

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