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Egbert Drenth

Manually flying ILS approach in IFR conditions

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Hi,I'm wondering if/how other pilots are flying manually ILS approaches in IFR conditions (i.e. with no visual reference to runway or whatsoever)Normally I disengage AP apon ILS interceptance and fly the approach manually, that is: if I have at least some visual reference to the ground/runway.When I don't have any visual reference, I find it rather difficult to control the aircraft manually. Pretty soon I deviate from both the GS and CDI, specifically maintaining a proper descent angle is very difficult.How do you guys fly manually in full IFR conditions?Just curious,Egbert

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There are several classes of approaches based on minimums (runway in sight and forward runway visisbility or RVR) and aircraft and airport equipment, plus crew training, then if obstacles allow. As the approach type number increases, lower minimums are acceptable.The most difficulty encountered in controlling an aircraft manually using just instrument references is 'chasing the needles' where over controlling the aircraft occurs. In this situation the aircraft is on one side of the mark then after correction gets to the other side before movement can be stopped.The first thing is to get into a stable merge and have the aircraft properly configured for landing and airspeed far enough out. Be sure especially your pitch trim is within the recommended setting. Use gentle corrections and don't dive or turn playing catch up too fast with the indicators. Let the indicator come to you. Use anticipation to keep ahead. If you are flying too slow your controls become less effective and you could get near stall conditions. If you are too fast you might not have enough time for the correction to become effective and your controls could become too sensitive. You also must make sure your aircraft is not overloaded so the specified landing weight is not exceeded and your weight and balance is within limits. When loading fuel pay attention to the FS CG indication. The CG limits are designed so at normal airspeeds the nose will lean toward pitch down as your elevator becomes less efective as IAS decreases. If the opposite were true your aircraft may not be able to recover from a stall. Therefore pitch trim adjustment must be correct entering the approach phase so you can accomplish gentle control movements.If you are in gusting headwind component add half the gust speed to the normal landing speed for your flaps schedule.You also might find some tips here at this enjoyable web site. While not an airliner site the same principles apply. The writer is a retired corporate pilot who flew many hours in a Cessna 402 twin and is a CFI and CFII.http://www.stoenworks.com/Aviation%20home%20page.html

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5 tips:Get correctly set up before ILS intercept. Correct speed, flaps set and once on glidepath, correctly trimmed. (It's more difficult to get the aircraft trimmed in FS than in real life, because of lack of aerodynamic feedback with the yoke.)Do your instrument scans faster. Much faster, 100x faster. Keep checking the VSI for the correct rate of descent for your groundspeed. You should find a table in the AIP regarding which rate of descent to use for a specified groundspeed.Try and fly slower as you'll have more time to react to needle movements. If you're in a large transport category aircraft fly at Vapp or Vapp+5.In a crosswind situation the slower you go, the more drift you'll need. Drift can be up to 30 degrees in a light aircraft.Don't try and 'chase the needle', especially during short final. the needle gets more sensitive as you get closer to the runway.

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Hi,Thanks for your replies.I'm sorry but I haven't made myself clear enough. I do know how to fly an (IFR) approach and how to configure an aircraft for landing.What I meant is the lack of any visual reference (and physical reference, i.e. 'flying by your pants' but that is of course impossible anyway)In full IFR conditions, when visual reference to runway or ground is missing it is very difficult to see (and feel) how your aircraft is responding to your inputs.Way too often I find myself deviating because of too much control inputs.I wondered how other sim pilots cope with this or don't have this issue at all.Egbert

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IFR stands for Instrument Flight Rules. Your instruments are your primary means of seeing what is going on.Visual references are not needed. In fact they can deceive you in Instrument Meteorological Conditions.Focus on what your instruments tell you.

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If you are performing an approach in IMC you should not be looking out the window at all until you get to DA. The whole purpose of an instrument approach is to allow you access to a runway in lower weather conditions, this could be solid IMC, you could be in and out of clouds, but what it comes down to is do not look out the window and trust your instruments. In the real world, what you see out your window can be VERY distracting and confuse you.You must learn to fly your particular aircraft and configure it appropriately for the given circumstances, and each aircraft is different. Develop your scan and learn what each instrument is telling you. You'll face various weather conditions which all play a role in your power settings, speeds, configurations. The above advice is what you should follow - an ILS will get more sensitive as you approach the runway so try to avoid chasing the needles. If you are flying a VOR approach the same will apply depending on your relation to the station...is the station located on the field, or are you tracking outbound on a radial taking you to the runway? GPS/RNAV approaches, you don't have to worry about needle sensitivity. You'll have various minimums prescribed depending on the approach you choose. Precision approaches (ILS) have the lowest minimums (will get you lower and closer to the runway) and non-precision (VOR, NDB, etc.) have higher due to lower accuracy of the equipment. Nowadays, WAAS is becoming more dominant which takes a GPS approach and creates a "pseudo" glideslope similar to an ILS with lower minimums.Here's the catch in all of this....unfortunately, Microsoft Flight Simulator does not give you the feel of a real airplane, nor does it simulate weather, or aircraft dynamics accurately. There are a few companies that create add-ons which come close. You'll have to learn all of this within the limits of the simulator. But you CAN learn procedures and how things work. Especially, if you have certain add-ons.Carenado aircraft are very good and the Reality XP gauges are fantastic. The RXP stuff performs true to real-life with fluid, smooth movement which makes flying instruments realistic. It's expensive, but very well worth it if you want to get as close to real as you can (currently) get.But at the end of the day, I still find myself getting frustrated with the simulator itself for it's lack of everything else, and with the unrealistic control inputs and joystick sensitivities that have to be adjusted for every single different airplane. It's very nice having all the fancy add-on planes and equipment, but at the end of the day, you're still flying in that same base program. You gotta learn to work with it.Robert

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If not already provided in your control input software consider the paid registration version of FSUIPC which can give you non-linear control input response. As an example I use it for the yaw axis making the pedals less sensitive around the center position to make nose wheel steering less sensitive for taxiing. I still have full rudder deflection at the end of pedal travel. These control axes non-linear calibrations can be saved on a per aircraft basis.Seat of the pants flying is pretty much useless for attitude flying in IMC. If you try to maintain straight and level by feel without instrument reference in blind conditions most pilots will end up in a descending death spiral.In order to get PPL and CPL certification, recovery from unusual attitudes with the hood on to simululate IFR is mandated for GA aircraft. The check pilot will lower the hood over your vision or you lower your view so as not to see instruments and then put the aircraft through a series of steep maneuvers to knock your senses off. He'll then allow you to look at the instruments only and expect you to recover. Usually the attitude indicator has 'tumbled' beyond correction and you recover by looking at the airspeed increase or decrease, turn coordinator, altimeter changes, and if time VSI, to recover as necessary to straight and level flight at your assigned altitude. The point is senses are useless. As an airline passenger I have been in holding patterns and possibly delay vectors in solid cloud and the seat of the pants senses are very misleading and I felt a mild case of vertigo.So even VFR training includes some instrument attitude training should a pilot inadvertently get into IMC. During that training you are constantly reminded to trust your instruments and how to use partial instrument flying should one of the primary instruments fail.One of the harder elements in an IMC approach where you will meet some minimum visual condition near the runway such as a 200 feet AGL minimum for a CAT I approach, especially for faster aircraft, is at the transition from your instrument scan to your outside view. This is why the HUD became important as a solution on larger aircraft where the HUD shows the minimum flight indicators superimposed over the windscreen.The lack of valid or false 'seat of the pants' indication can often lead to over control of the aircraft with a panic response especially in a turbulent condition. This is why gentle control corrections is needed because of the delay in instrument response.Some FS models tend to be too sensitive in elevator effect I've found resulting in over control by the A/P. I sometimes in the aircraft.cfg reduce the elevator effectiveness or elevator trim effectiveness just a tiny bit.If you are on a stable configured approach gentle control movements to just start the correction should be all that is needed. If your controllers do not allow that then if no software is available for your controller consider FSUIPC to dampen sensitivity in the around the neutral position of your controller. By using a non-linear calibration curve you'll still have full control effect when you need it.I suggest you train on a GA aircraft first and then progress through stages to more advanced higher speed heavier aircraft. Do this first in visual conditions with a new model to get the control feel of following the instrument approach and then in IMC.It takes discipline in real aircraft to ignore most seat of the pants indications in IMC.BTW, quite a few years ago when I acquired my CH joystick I issued a complaint about the sensitivity being very high on the trim adjustments. Their response was that really was not the intent of the control but more of a fixed setting to allow for manufacturing parts tolerance!. There is too much control even if you wiggle around the neutral detent. I just do that to exercise it to get rid of electronic noise (oxidation) in that section of the trim potentiometer. I can't speak for other brands. So I'm stuck with mouse or keyboard adjustment for trim. In heavier aircraft the trim setting is usually specified especially since this determines the range of control by the A/P which uses trim for pitch control.

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What I meant is the lack of any visual reference (and physical reference, i.e. 'flying by your pants' but that is of course impossible anyway)
The WORST thing you can do in IMC is to try to fly by physical references, what your body feels and your brain tells you can lead to dangerous situations. You NEVER believe your body, EVER.Igor

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I practice. If i pick up a new type, I spend an evening finding out how sensitive it is. If I like it I'll set up and save a flight on a long final with no visibility and fly the approach a number of times until my control is smooth. Then if I think I need it, I'll do the same with various cross winds just to be sure. I think the point of IFR is that you don't need any external reference points.Sounds anal doesn't it? But... it doesn't take long to become accustomed to the conditions and to the aircraft (and to using the instruments instead of the view) so it's not a big chunk out of my life; an evening is usually plenty. And I've got (FS)9 lives.I find if I enter the glideslope with the plane already configured for the approach, in straight & level flight and already at the approach airspeed, control is much easier on the way down. I avoid using the trim wheel though I don't know if that's normal in the real world, and tend to rely as much as I can on throttle to maintain the correct approach. However, I'm not yet flying big heavies and they may behave differently. I have a very cheap joystick which gets a lot of movement in the last minute or so of the approach while the aircraft still flies relatively smoothly. I imagine that the movement I make corresponds to pressure on a real-life stick.D

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Don't chase GS and CDI, just follow the FD (assuming the plane is equipped with one).Wolfgang

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Hi,I'm wondering if/how other pilots are flying manually ILS approaches in IFR conditions (i.e. with no visual reference to runway or whatsoever)Normally I disengage AP apon ILS interceptance and fly the approach manually, that is: if I have at least some visual reference to the ground/runway.When I don't have any visual reference, I find it rather difficult to control the aircraft manually. Pretty soon I deviate from both the GS and CDI, specifically maintaining a proper descent angle is very difficult.How do you guys fly manually in full IFR conditions?Just curious,Egbert
Hi,Thanks for your replies.I'm sorry but I haven't made myself clear enough. I do know how to fly an (IFR) approach and how to configure an aircraft for landing.What I meant is the lack of any visual reference (and physical reference, i.e. 'flying by your pants' but that is of course impossible anyway)In full IFR conditions, when visual reference to runway or ground is missing it is very difficult to see (and feel) how your aircraft is responding to your inputs.Way too often I find myself deviating because of too much control inputs.I wondered how other sim pilots cope with this or don't have this issue at all.Egbert
Instrument scan! Don't focus on any one instrument, pay attention to all. Don't just look at the ILS indicator (or flight director if the a/c has one) - check ADI/Attitude, HSI, Vertical Speed, altitude, airspeed, etc... For IFR ILS manual approaches Scan the Primary Instruments continuously.I found this is the best approach and it has let me do some fine landings in the PT Tu-154 (and other aircraft) at night, during heavy snows and crosswind. You also have to be comfortable with the plane you're flying and it helps to have a familiarity with the airport where you're landing. Its best to use gentle movements, especially in an airliner. Try not to make too heavy aileron inputs or too many inputs, and try not to overcompensate.It can be a little overloading at first having to do all these things at the same time but with practice this all becomes almost second nature. If you're stubborn enough and stick to it, at some point you start to do all these things without even thinking.These are some useful articles:http://www.borzov.net/Pilot/FSWeb/Lessons/Instrument/InstrumentLessons02.htmhttp://www.pilotfriend.com/training/flight_training/nav/ifr_scan.htm

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add the stick sensitivity mode to your cfg, linear input is way better than the logarithmic default one.

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Regarding stick sensitivity:You do need some neutral zone in the FS sensitivity to get rid of any noise at the neutral area. The stick will also not return exactly to the same value as you release it to the detent. However, the more neutral zone space you assign the more sensitive the stick since the range is now distributed over a shorter range window.

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Don't chase GS and CDI, just follow the FD (assuming the plane is equipped with one).
I have nothing but trouble using the FD -- end up chasing it all over. I do better with raw data (deviation indicators).scott s..

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Good advice so far, Egbert, and I'll just add that flying IFR approaches in FS is harder than in the real airplane, in my experience, so don't feel bad. It takes a lot of training and practice to master instrument flying in the real world, and the skills perish without constant practice. I highly recommend picking up an IFR textbook and paying particular attention to the section on attitude instrument flying and the 5 T's.

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