brauner1

locating the aiming point during landing

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I have came across many references to using an "aiming point" in order to judge current FPA for assisting the glide path. However even low as  500' it seems to be impossible to actually see such a point where detail remains stationary along the trajectory. Obviously when FPA diverges to a great level (more than 9 degrees or less than 1), it is visible that the runway surface wont be hit anymore, but when it comes to subtle changes (as it always is during final) its difficult to identify which of the gray pixels along the center line would represent the aiming point, and how it moves in meters every second.

Any contribution to the subject would be appreciated.

 

 

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I believe the unfortunate limitations found in current computer simulations of flight are the factor that we are dealing with.

Higher resolutions will probably help in locating that point where detail remains stationary enough to help with assisting with the glide path. 

I'm currently utilizing a 50" 4K television as my monitor and it definitely has helped, overall. 

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If the aim point being used is not easily distinguished, then that may be part of the problem. Look for a distinctive mark on the runway to aim for such as the end of a stripe, the closest edge of a taxiway, a light or any other point that is clearly marked on the surface.

Then it is important to choose a good reference point within the cockpit to measure change in the distance between the two references. For example, the distance between the top of the glareshield and the beginning of the first stripe on the runway should remain constant.

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The aiming point is either two rectangular broad white stripes located on each side of the runway centerline which are approximately 1,000 feet from the landing threshold (not always, but generally speaking this is the case), but they can (and often do) also comprise six stripes, three either side of the centreline in an offset line, see pictures below.

Note that if you can't see the stripes of the aim point in your simulator, there are two things which are generally more visible and which are directly in line with the aim point markers, which can  help you locate where on the runway the aim point is, these being the VASI (PAPI) lights on the grass to the left of the aim point markers (usually painted red and white) and the glideslope antenna (usually painted yellow) on the grass to the right of the aim point markers.

Here is what all the runway markers mean with some pics to help...

Below is the threshold marker, beyond this is the displaced threshold which is not normally stressed for touchdowns, but can be used to line up on for a slightly longer take off run:

GNrxhzf.jpg

Next, this is one of the 500 feet markers, which as their name implies, are placed every 500 feet along the runway:

2gHhj4s.jpg

This is the aim point marker, as you can see from the 500 foot marker beyond it, it is 1,000 feet after the threshold of the runway. A point in between that 500 foot marker and the threshold marker (where you can see some darker tire marks) is about where you would touchdown for a landing if you are doing it right (some runways have a dedicated touchdown maker, which is like a smaller version of the threshold marker, i.e. a series of white lines), in other words, you don't land on the aim point, you use it to take you to the flare so you can come down on the correct touchdown point:

Kvf5MgT.jpg

Below you can see the aim point is not particularly visible although it does extend wider than the lights, so you can just about make it out, but even if you couldn't see that, you can still tell where it is because it is in line with the VASI (PAPI lights) although since the lights are mounted on a pole, the touchdown marker is visually ever so slightly lower down in the sight picture. If your eyesight is good, you might also be able to make out the glideslope antenna to the right of the runway in line with the aim point marker.

Note that I was doing a fly-by here to get the screenshot and so this is not a correct sight picture for an ideal approach, as it is too low and the pitch and speed are not correct:

gjJdBw5.jpg

Generally speaking, what you do, if you don't want to use the VASI (PAPI lights) for your approach, or if there aren't any, is pick a spot on your windscreen (for example, halfway down it, perhaps in line with the label on the bracing tube in the Bellanca Viking in the above pic), and then keep that point on the aim point until you are certain you are 'in', then you come back on the throttle and the stick (or yoke) and look to the end of the runway to keep yourself tracking in straight as you ease it down with stick back pressure. In real life the grass flashing past in your peripheral vision is a big help toward judging your height, but in a sim that doesn't work quite so well unless you have three monitors with side views, so you have to kind of blag it a bit.

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Thank you for all the thorough explanations. Im using the Q400 where the windshield is relatively large, so the distances between the edges or the top end of the monitor are about 5-10 centimeters. Therefore drifting of milimeters per second goes largely unnoticed, even though it affects whether the thouchdown point will be on the threshhold or 1/3 down the runway. Perhaps a large unobscured forward field of view depicted by a PC screen makes it visually a more challenging task then it should?

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If the above makes sense, then I would suggest that the next step is practice. Practice makes perfect! :)

Also make corrections early and often. Lots of small corrections made as soon as any drift is noticed is much better than large late corrections.

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5 hours ago, brauner1 said:

Thank you for all the thorough explanations. Im using the Q400 where the windshield is relatively large, so the distances between the edges or the top end of the monitor are about 5-10 centimeters. Therefore drifting of milimeters per second goes largely unnoticed, even though it affects whether the thouchdown point will be on the threshhold or 1/3 down the runway. Perhaps a large unobscured forward field of view depicted by a PC screen makes it visually a more challenging task then it should?

Yup, personally, I think it is harder to land an aeroplane in a simulation than it is for real. Simulators, certainly static ones, don't visually convey inertia very well, and even if they do, without the feeling of being there one has in a real aeroplane, we are inclined to make up for that by over-controlling instead of letting the aeroplane ride along, which it will do if you let it. You can see this if you watch anyone who is used to PC-based flight sims having a go at trying to fly a real aeroplane; the first thing they have to get used to is that whilst aeroplanes certainly do bounce around a bit, that movement does not mean they are going off course, they tend to keep on going where you point them because they have a lot of mass, so you have to learn to fly your sim aeroplane like you fly a real one, i.e. get it heading where you want it to and only correct trends instead of mistakenly viewing every minor deviation of a few pixels as being something you must immediately counter with a control input. You don't fly a real aeroplane like that because in a real aeroplane you are very aware that it is several tons of weight going through the air; minor bumps of turbulence are not going to stop several tons of metal from going in the direction it is already going.

I can remember that fact eventually dawning on me when I was learning how to stay in formation with another aeroplane for real. At first I was constantly trying to correct every tiny little movement to stay absolutely perfectly in place as though I was attached to the other aeroplane by a rigid connection, which you simply cannot do; if you try you just end up making things worse. So my first attempts at formation flying were of course appallingly bad and it was all because of over-controlling lol. Eventually you figure out that the real trick to flying in formation is that there isn't a trick to it at all, you just let the aeroplane make its undulations and leave the bloody controls alone, only correcting any very obvious indication of it drifting out of place.

It's exactly the same with landing the things. Get it going the right way and then let it keep on going that way with only the odd nudge to ensure it does.

 

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Minimizing control input, and trusting the aircraft to keep a precise trajectory does help immensely at achieving very fine results. Also, zooming in for more detail seems to be a bad idea. I found using atleast the default 0.7 level to be more useful, as while maintaining contact with a single point/pixel isnt very practicle, it is still somewhat possible to maintain a sight picture (section of the runway from the threshhold up to VASI) constant relative to elements on windshield frame. By 100', specific runway markings can be utilised instead. A wider view also allows much better awareness regarding flight deck angle for constant pitch hold.

Again thank you for all this critical practicle information.

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All of the information and advice here is excellent - there's little to add to it other than to agree that practice and experience are the main ingredients so don't worry if it's not perfect each time - in the real world it rarely is! It really does come down to instinct and feel and if you fixate on trying to land on an exact spot you are making things harder for yourself than is necessary. (Unless you're landing on a carrier of course!) :biggrin: I'd suggest you relax, not expect perfection and remember the old pilot adage - "any landing you can walk away from is a good one!"

Cheers

Ian

BTW - "Chock" is right on target when he says that flying a static simulator IS much harder than the real world for the very reasons he mentioned. There are so many visual and tactile clues that in the real world you take for granted until you first fly a PC based simulation and realize that not having them makes it difficult. Of course, you do have a pause button which would be very welcome in the real world so that is some consolation! :cool:

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# 1. Choose an airport with PAPI Lights ( PAPI = Precision Approach Path Indicator ) .

The last screenshot above with the brown panel has the PAPI lights to the left of the runway , it indicates 3 red and 1 white , actually that aircraft is

below the glide slope as is indicated by the 3 red lights .

If you are precisely on the glide slope it will always indicate 2 white and 2 red , you gently adjust your pitch  (nose up or nose down)  to constantly

maintain the 2 of each white and red all the way down during approach .

Virtually all approaches are done at a 3 degree glideslope and that is what the PAPI lights guide you along . 

... 3 or 4 white light indicate that you are above the glideslope (lower your nose)

... 3 or 4 red light indicate that you are below the glideslope (raise your nose) 

 

# 2 . During your approach you should ideally trim (elevator trim ) the aircraft so that it will fly the approach virtually hands off 

ie; basically it will then require very little control input and will tend to fly a smooth constant approach path .

 

# 3 . When you have 2 white and 2 red PAPI lights indicating that you are on glideslope  , hit Pause ( pause the sim ,

the place a length of cotton horizontally across your monitor screen at the exact height of the PAPI lights , tape the

cotton on each of the monitor side frames .

Resume the approach (pause off)  , the cotton line should remain on the PAPI lights for the rest of the approach .

That cotton line can later be placed on any "aimpoint" on any runway and if it is kept on that aimpoint throughout the approach

your glideslope will remain constant and you will fly accurately to your aimpoint (touchdown point) .

 

Cheers

Karol

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On 10/25/2017 at 0:28 PM, FlyAndFight said:

I believe the unfortunate limitations found in current computer simulations of flight are the factor that we are dealing with.

Higher resolutions will probably help in locating that point where detail remains stationary enough to help with assisting with the glide path. 

I'm currently utilizing a 50" 4K television as my monitor and it definitely has helped, overall. 

Is there anything involved other than a HDMI cable in making that work?

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Regards the approach to landing " Aimpoint " on a runway you do not need a specific painted spot on the runway , as you will be

aware grass runways have no paint on them .

The object of an aimpoint on a runway  is to direct the aircraft to a location at the beginning of that runway , you need to clear the runway

threshold and leave sufficient runway left after touchdown to slow the aircraft to a halt before the end of the runway .

You estimate and visualise your aimpoint a small distance past the beginning of the runway , and fly to that point .

 

I created a " Synthetic ILS " instrument that enables absolute precision approaches to be conducted along a glideslope  for

all runways at all of the 24,491 airports that exist in the Flight Simulator database .

What it does is it reads the applicable runway length from the FS database and calculates an "Aimpoint" that is

6% of that length in from the beginning of that runway , from that aimpoint it determines the glideslope (usually 3 degrees) ,

and provides guidance using the standard ILS deviation bars  , thus by keeping your ILS deviation bars exactly centered

you precisely follow the glideslope all the way down the approach to the Aimpoint on the runway .

 

Cheers

Karol

 

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10 hours ago, eelb said:

Is there anything involved other than a HDMI cable in making that work?

Hi eelb,

Aside from the HDMI cable and the comparable video card, that's it.

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On some particularly short fields the aimpoint may need to be prior the the beginning of the runway.

It all depends on the situation and, as COBS said, there isn't a need for a painted mark or a PAPI for the most basic aircraft and fields.

With practice, choosing a point, any point, on the ground and flying toward it is a skill that every aspiring pilot must develop. In fact, this skill is called into play every time an instructor pulls out the power and says the words, "Your engine has failed..."

In light single engine aircraft you are taught to fflymonitoring points along ttheground. You never know if you'll need to glide ro that last point you saw in an emergency.

I thought I would have to call upon this for real on a flight I did just a couple of months ago. My engine hesitated for a few seconds and I knew within a few seconds that I could turn left and land in that empty football field off to my left.

Keep practicing! Don't overthink it.

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