ILS, glideslope, aircraft nose pitching down

Hi,

 

When performing an ILS, on approach, the flight director is turned ON and the plane's nose is usually leveled with level flight or slighty pointed towards the sky which can be seen on the primary flight display. Now everytime the glideslope gets leveled with level flight the plane starts descending but the aircraft pitches down a few degrees then reverses itself back. No matter what plane I use addon or default, is this normal in FSX/FS2004 or am I doing something wrong? Here's example in the video :

 

https://www.youtube.com/watch?v=ikct2VliROo&feature=youtu.be

 

at 35 seconds in from the video the plane pitches down when the glideslope reached level flight.

Looks normal to me

Normal. The plane is just pitching down to stay on the glideslope.

oposite to last replies, i dont think its normal

My decents usually put aircraft horizontal or slightly on positive pitch.

I would related to that 185 knot speed mixed to flaps on max.

That speed shouldnt go over 150 knots.

The speed really depends on the aircraft. I'm not flying my B747 at 150. No way, no how!

On final ILS/Glideslope approach with wheels down, flaps full in my 747 or A380, my touchdown speed is set for 155 knots. I agree that 185 is too high.

Yes in the video I was at 180-190 but even if I'm at 140-160 with full flaps and gear down, the plane will still pitch down. I don't know how lefu is doing it

Yes in the video I was at 180-190 but even if I'm at 140-160 with full flaps and gear down, the plane will still pitch down. I don't know how lefu is doing it

 

ok..

how are your joystick settings ?

if its bad calibrated it might be causing the horizontal stabilizer to pitch the plane down.

Would be even more possible as you said it happens with any plane.

 

looks like an A320 on your video, can you calibrate the trim on it ?

 

final approach speed shouldnt go over 140, my wilco a320 can be landed at a comfortable 135 kts.

I don't have a joystick, I'm using a gamepad, it's a little easier than keyboard. But then again both gamepad and keyboard does the same thing. I'm using a 737 in the video with an airbus cockpit. If gamepads can be calibrated where can I find their settings so I can try and see if it is the cause.

You should modify your approach speed and flaps so the pitch when captured and stable is per specification for the aircraft weight. What you are trying to do is FIND THE SPEED AND FLAPS which provide the correct pitch (if you don't know what they are.)

 

One way to find out what they SHOULD be is read the documentation for the aircraft. Often, these speed/flaps/weight settings are in the kneepad specifications.

Not every plane lands at full flaps at all weights and speeds. Also, flaps are typically deployed in stages as the plane slows down, not all at once. By flap staging, you reduce the over-compensation while trying to capture/hold the GS in APP mode.

Also telling us what is the file for that 737, and the file for the airbus panel.

I could try them both tonight.

why not download 737 panel ?

loooks like 737 in video.

190knots, 737, level flight, but... nose is up. That means you have no flaps set, way to late.

 

Descent, you set 180, but, in a descent you will not slow down of course. To little to late.

 

FOB=44437 lbs. Way to much fuel to be landing.

 

While descending along the glide slope the nose IS level! (look at the artificial horizon.). Looking out the window can give the wrong impression.

 

Go around and dump fuel over the bay.

Set "full flaps -2" on downwind, "full flaps -1" on base leg, full flaps on final approach, approach speed try 160. Come in flying 160kt, full flaps when still 20NM from the airport.

After that there really is no more time to adjust things. It's not an F16...

 

Try again, you'll get there.

 

In a b738, "full flaps -2" is flaps 25

"full flaps -1" is Flaps 30

"full flaps" is Flaps 40.

Allright here's another one, kinda better but still pitching slightly down. Plane is completely empty on weight and 0 fuel. I couldn't full flaps after plane starts descending, tried it and it kinda nose dived crashing after reducing speed to extend more flaps. The aircraft is the same, it's a posky 737W. Ignore the fuel warning because I tried so many attempts. I've seen some videos around and they all nose dived a bit after glideslope reaching level flight. I think speed is the main factor, depending on the aircraft's specs and weight of course. There is just 1 thing that's been getting me wondering since I've learned the ILS landing. Sometimes the plane's throttle increases and decreases simultaneously over and over on final approach, why does it do that with some planes? At the end of the video I have shown an example with accelerated time to see clearer the difference. It's been doing that also in the approach and you can clearly hear the engines increasing and decreasing seconds after seconds.

 

https://www.youtube.com/watch?v=yFKviSXCalc&feature=youtu.be

I don't have much time now, and didn't watch the vid.

But, one thing, you should have full flaps set well before it starts descending.

 

When on the last 20 mile straight path, have full flaps set already, and speed at 160 kt.

Altitude then should be around 3000 ft AGL.

Yes, flaps deployed at full before glideslope reaches level flight. There is the throttle behaving weird which I'm still trying to figure out why it's doing that.

It says in the center of your dashboard. Max speed full flaps is 177 kt. You are doing 100. Not enough. Only go just below 177.

 

You switch off AP and AT too late.

 

It says flaps 40 in the display, yet the green flap indicator does not show it. No idea why, no idea if it is a problem.

 

The nose should be level in a descent, not up, as in your video.

 

Before landing you should switch off the AP and AT and Manually raise the nose a little.

 

The engines reduce thrust to descend, but you are so slow you would stall, and thrust is increased again to stop the speed from reducing.

If the engines do this in level flight also it is a problem with the aircraft you downloaded.

Or maybe it is because you left the engine starters running. But it's a bit of a guess.

 

Looks like your plane is overweight, even without the fuel.

Check the fuel and payload menu. Compare the weight of the default 737 with that of this 737.

This addon could just have the wrong weight. Or the wrong center of gravity. Hard to fix.

 

From your first post: "the nose goes down when I descend" -- Well, of course it does. It is supposed to do that.

 

From your posts: "when the glideslope reaches level flight." -- The glideslope goes down all the way to the runway. It does not "reach level flight" at all.

 

Hard to see in your last flight, but, if you crashed, then that was because you were flying only 100 kt. when you pulled up the nose, the plane stalled and crashed.

 

You are making some really basic mistakes, like, flying at 100 kt in a 737.

Try to get a feel for how huge an aircraft is. How difficult it is to make such a large thing slow down, and how much time it would take to increase speed. Just try slowing down a brick that comes at you at 100 kt (120 Mph / 180 Kmh). Imagine trying to stop it with your chest. Now imagine trying to stop a train coming at you at that speed. :) You are not flying a light aircraft. You are in a 737 that weighs thousands of pounds and is moving ( should be moving) at high speed.

 

*******

Flying at 100kt.... if you pull up the nose at that speed, you will stall and crash right away!

I think you need a lot more practice, and some reading.

Practice in the default 737 or 747.

Those aircraft have no flaws in weights or working flaps, and are perfect to learn how to fly in.

Also, since many flew those aircraft, you can learn by reading the experiences of others. And using the FSX manuals.

 

Posky's have issues sometimes.

Once you get the default 737 and 747 under control, and can land them with 100% confidence move on to other aircraft.

Only then can you judge if it's you that is doing something wrong, or the aircraft.

 

********

Here's a view from the default 737, following the glideslope at 157 kt. That's how it should look.

Have a close look at:

*Flap setting - Speed,

*Distance to the airport (distance to SPL),

*Altitude (airport is at sealevel).

*position of nose on artificial horizon.

 

Approaching:

 

A bit closer:

 

Just before hitting the glideslope:

 

When descending down the glideslope:

From your posts: "when the glideslope reaches level flight." -- The glideslope goes down all the way to the runway. It does not "reach level flight" at all.

 

Firstly, great post! This is an excellent "mini tutorial" on flying an ILS in a 737, or any similar-speed jetliner.

 

I, too struggled with the concept of "when the glideslope reaches level flight" because, as you so succinctly pointed out, the glideSLOPE is a SLOPE :) and no part of it is ever level. I finally decided that what the OP means is "when my level flight path intercepts the glideslope."

 

Finally, it has been my observation that (almost?) all large airplanes fly 3-5 degrees nose up when flown at a constant altitude ("level") at Vref +5 or so with landing flaps. Then, when the glideslope is reached and the descent begins, the nose drops to more or less 0 degrees of pitch. The angle of attack is still the same, the airplane is still flying nose-up with respect to the relative wind, but the deck angle is reduced to account for the descent.

Did you fly the same 737 with A320 panel in the video ?

I dont know what to say..

100 is way too low, the weird engine sound you are listening is when the automatic throttle increases power so the plane keeps its way in the glideslope.

Althoug the flight director shows the plane on a positive pitch, small, but positive, so the plane is not pitching nose down, and in fine orizontal descent.

I only once, added a panel to a different plane.

I added a harrier panel to default f18, i couldnt move flaps during thw whole flight.

I never suggest and will never use new panels on a different aircraft.

I would add a 737 panel to a 737 aircraft. thats all..

To clear things out, I'm using an A321 panel on this aircraft because I'll have too much panels to work on as in, installing, editing etc etc. I'm currently using 3-4 not more. So excuse why I'm being kinda off track here with the panel.

 

Secondly, I think that aircraft isn't that good to fly with. Sadly most of my planes are from posky so does other people uses it but here's the thing.

If I increase speed to 150-177 IAS the plane will nose pitch down due to high speed. As I said previously I emptied the weight and fuel for a try and it seems overweight as il88pp said. I'm going to compare it with the default 737.

I've been flying for years like that, was just wondering when the glideslope reaches level flight (pink diamond reaches middle or below level flight) why the nose pitches down a few degrees and if it's normal, majority say it's normal. Even in youtube videos it's the same and that's where I've learned the ILS.

As for the engines increasing/decreasing over and over, it was doing that without any approach, I was flying at low altitude. I'm going to compare it with default and other planes because that is just annoying and unrealistic so does flying 100 on final.

To clear things out, I'm using an A321 panel on this aircraft because I'll have too much panels to work on as in, installing, editing etc etc. I'm currently using 3-4 not more. So excuse why I'm being kinda off track here with the panel.

 

Secondly, I think that aircraft isn't that good to fly with. Sadly most of my planes are from posky so does other people uses it but here's the thing.

If I increase speed to 150-177 IAS the plane will nose pitch down due to high speed. As I said previously I emptied the weight and fuel for a try and it seems overweight as il88pp said. I'm going to compare it with the default 737.

I've been flying for years like that, was just wondering when the glideslope reaches level flight (pink diamond reaches middle or below level flight) why the nose pitches down a few degrees and if it's normal, majority say it's normal. Even in youtube videos it's the same and that's where I've learned the ILS.

As for the engines increasing/decreasing over and over, it was doing that without any approach, I was flying at low altitude. I'm going to compare it with default and other planes because that is just annoying and unrealistic so does flying 100 on final.

 

what about joystick calibration ?

what about joystick calibration ?

 

See answer in post# 9 when you asked it the first time.;)

Well something is definitely wrong with my approach and I have no idea why.

 

Take a look at this, you can skip some parts, no need to watch the entire video.

 

Default 737 (FS2004), empty weight, average low fuel, engines keeps increasing/decreasing on final, nose pitched down until I lower more speed.

What is going on I don't know :confused:

 

https://www.youtube.com/watch?v=2nSnZ1hrFQU&feature=youtu.be

Some observations:

1) You are slowing to threashold speed too soon and the speed changes are too sudden (notice the engine RPM going up and down rapidly.) As your speed changes, lift changes and so is the pitch required to maintain the altitude.

You should time your speed changes in steps so you are just barely arriving at threashold speed 500 feet above the runway.

 

2) Flaps changes = pitch and drag changes (engine and speed changes)

Since you are over 25 miles from the runway at the start of the video, you should be holding APPROACH speed (usually 180 knots at documented minimum landing weight) AT LEAST until you get within about 13 miles. Until then, you should be holding ONE speed and ONE flaps setting. Find the flaps setting which gives you 2-5 degrees pitch at 180 knots and keep it until getting well within glide slope range (no sooner than 9 miles from landing) at which point you will GRADUALLY reduce speed and final flaps settings AFTER gear is deployed.

 

There are other details, but your primary problems right now is you are slowing to threashold speed and flaps, 16 or more miles too soon and you are changing speed/lift faster than the AP/AT and engines can spool to compensate.

 

-Pv-

The more I reduce speed the more I have to extend flaps right? And vice versa, if I extend first then I have to reduce speed.

"The more I reduce speed the more I have to extend flaps right?"

 

Yes, but in the video you posted, you are doing both way too soon and too rapidly, not giving your AP/AT and engine spool enough time to compensate smoothly.

 

Do what you are doing closer to 9 miles out and while on the final approach glide path (descending) not 26 miles out and level like you are doing.

 

Set your THREASHOLD speed in 10 knot increments deploying your flaps in steps to keep the landing pitch as per documentation.

 

-Pv-