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How to properly gauge the impact strenght of a touchdown ?

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I think this is the most difficult part of the flight, how to properly touch down while landing.

 

Of course a good " grease " is a nice show but I was told that the most important thing is to land her down when needed, even if the impact is not very soft.

 

So, how can we gauge the touch down strenght when landing ? Sometimes, ( I bet everyone of us experienced it at least few times above all in the early flights ) , it happens to crash the NG due to excessive impact strenght while landing.

 

Thx

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At least in theory, if you descent at a normal rate (c. 600-700 fpm depending on GS), follow the glideslope properly (IIRC c. 100 ft height at threshold) , be near the correctly calculated IAS, retard the throttles at 50 ft above ground and flare correctly (not little, not much) at 10 (?) ft, you'll do a great landing...

 

From theory to practice it's a long long way, at least for me. Hadn't "flown" for quite a few weeks and my last attempt was a big mess, although everything was going on very well till almost touchdown. Guess I need to practice more... :unsure:

 

PS Correct me if the figures above are not true please.

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I know in the real sim i pulled the power back at 30 ft. off the deck and she come crashing down pretty hard which of course you won't feel in our sim. My kid is capt. on one of these so i was lucky enough to have him get me in one.

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Yeah that's not an easy task above all when wind is involved. Naturally the human mind tends to re-do the same procedure done in the last successful landing but each landing is different from the previous one, I would add that I have never landed in the same way within dozens of landings.

 

It would be nice, for training purposes, to have a gauge that tells you how hard or how gently your gear hits the ground, above all for the successful landings, where you can have an impression that is not true, above all in a sim where you miss the physical impact sensation.

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I came across a handy LUA script for FSUIPC that displayed your final fpm on touchdown

 

 
function onground(off, val)
if val ~= 0 then
landvs = -math.floor( (ipc.readSD(0x030C) * 60 * 3.28084 / 256) + 0.5)
ipc.display("Touchdown fpm = \n	    " .. landvs, 30)
end
end
event.offset(0x0366, "UW", "onground")

 

Copy the above and paste it into a text file, then rename it to touchdown.lua

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Touchdowns are as much art as science I'm afraid. Up until then it can all be done "by the book" but the actual flare and TD is by "feel" (something lacking in a simulator of course). When you get to the 30 ft callout, bring your power back slowly to idle. Raise the nose just a touch. You have a Body Angle indicator (Angle of Attack) on the PFD near the upper right side. Use that as a guide. It will feel like you are landing flat, but hold about a 5 degree attitude and let it fly itself on to the runway. You don't want to do like the light aircraft and keep holding off for a full stall landing or you'll float all the way down the runway before you touch down. You kind of gauge how fast you are sinking by how fast the remaining numbers callouts are. Below 30 feet the next call will be 20, then the call at 10 should take longer than the call from 30 to 20. After 10, raise the nose just slightly to arrest your sink, then let it settle again at about 4 to 5 degrees and wait for the wheels to touch. They will make a fair bit of rumbling noise as they touch, but that's normal. Practice that a few times and you'll get the hang of it. Now FYI, Boeing recommends you land these planes "firmly", so don't be afraid of touching down a mite on the "solid" side. You shouldn't trigger a crash warning obviously, but you don't need to grease the thing on every time (nobody does every time!). I don't know where (or how) they set the crash trigger point on this aircraft (I keep my Crash Detection turned off) so maybe it's a wee bit on the sensitive side. I don't know that, but at any rate, you still shouldn't be triggering it. Anyway, it's all timing and practice so keep at it. You WILL get it.

 

Now (the above aside), please tell me this isn't the first FS aircraft you are flying :smile:. If so, I think I'd move over to the 172 and get the hang of that first. Landing a 737 is a bit like trying to run an Olympic race before learning to crawl, and will be an exercise in frustration.

 

One last thing? If you feel this sudden kick in the butt and notice a tire is occupying the position where your floor was just aft of the centre pedestal immediately after touchdown? Chances are you landed a "tad" hard :lol:.

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The techniques are very nicely described in the FCTM. I feel that this is one manual most seriously underappreciated within simming community.

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The techniques are very nicely described in the FCTM. I feel that this is one manual most seriously underappreciated within simming community.

 

I agree : on page 6.10 of FCTM, the flare and touchdown are well described.

For me the most difficut is to increase the pitch altitude 2 or 3 degrees.. and no more ;-)

 

 

Guillaume

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I also use the mouse to fly the NGX so I think it is slightly trickier than using a controller.....and nope, this is not my first FSX plane but the NGX is definitely IMO the most sensible one...for instance landing a Level D 767 was far easier in terms of " crash " risk.

 

I am not telling the NGX is too sensitive, it is just that once every 6-8 landings I crash but maybe it is just for a personal feeling that force me to land her in the first part of the runway to end around the middle of it like I was landing on a carrier. I have to work also on this mind set first :)

 

btw the LUA script where has to be placed ?

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The techniques are very nicely described in the FCTM. I feel that this is one manual most seriously underappreciated within simming community.

Sadly, it's neglected RW, too!

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Even if you touchdown nice and gentle there will always be the bump.

The sound of the bang you hear is done by the shocks not the tires

 

I have been on a few flights now and every time there is a bump

 

If the plane is full of passengers imagine the weight on touchdown, even if the fuel is low..

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If the plane is full of passengers imagine the weight on touchdown, even if the fuel is low..

If the plane can accelerate in the vertical axis, then it can touchdown at just over 1G. A bullet doesn't weigh much, but it'll create a "bump," too. ;)

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one problem here is the gear you are using to land your plane, mine is a cessna pro flight yoke, it has 1 1/2 inch IN, 1 1/2 inch OUT Y Axis movement, so a little movement of the yoke make a big movement on the airplane. So when landing i have to over correct the airplane so it lands safely. the real thing is a lot easier on that part. I watch the repetition of every landing to see how it was and i have the FSX Detect Crashes ON.

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I pretty much just fly em on to the runway.. A little flare, but not that much.

I don't watch the gauges except for the speed.. I watch the outside view to

gauge how much to flare, etc..

And I can land sliightly different depending.. Sometimes I'll do a greaser

if the wx is good, and the runway long.

Bad wx, or short runway, I plop em down fairly firm.

Another thing I sometimes do is to add a wee bit of forward yoke right before

the touchdown. This flattens the plane a tad and makes for a smoother landing.

I've never had the NGX indicate a crash yet on landing. But.. I don't recall

having any *really* bad landings.. I land fairly decent most times.. :)

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David already recommended the LUA script, but as an alternate, I can recommend a freeware program called Flightlogger Blackbox. It allows you to log your flights, and view a 3D representation of your flight in Google Earth. This utility also shows your touchdown VS on the part of the runway you touchdown on inside of Google Earth.

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HI Marx,

 

What I've been taught is that, most importantly you should arrive over the tresshold at Vapp, at 50feet AGL and decending at a 3degree glide. When you hear the 30feet call out slowly bring the power to idle. at the 20 call out raise the nose to arrest the decend. Let the aircraft settle on the runway. if you are light bring the power back sooner than if you are heavy. Or if it's hot vs cold.

 

Also remmember to look far down the runway to better guage your height and vertical speed. Slightly different for the different aircrafts. The 800 likes to float. Especially if you are a little fast. The 700 is really easy!

 

This works for me in real life.

 

Kind regards,

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