I noticed that while rotating on the PMDG 738, the nose coming up super easy at first and then its like almost stops and i have to apply almost 2 times more back pressure to make it finally leave the ground.

Is that a Boeing feature or something else i am missing ?

Edited 16 hours ago16 hr by roi1862

I assume that you are not rotating too early? I do not have any problems at take off in the 600/800/900, but then I fly a reasonably light aircraft (no passengers or cargo).

3 minutes ago, Christopher Low said:

I assume that you are not rotating too early? I do not have any problems at take off in the 600/800/900, but then I fly a reasonably light aircraft (no passengers or cargo).

No. Rotating right on time. I am not sure if i my rotate rate is too fast and there is some tail strike protection or something...

Edited 16 hours ago16 hr by roi1862

Cant say I have ever noticed it.

Is you elevator trim setup properly.

Should be pretty much automatic.

Flap setting?

Standard 10 to 15 rotation?

On the 747 there is a slight natural resistance as the tail plane experiences a cushioning ground effect as it gets nearer the ground on rotation requiring you to smoothly pull through it.

I don’t know if the 737 has similar aerodynamic characteristics or indeed if that’s simulated.

Yes it's a Boeing feature. It's called the "dead band" and is around 10 degrees pitch during the rotation. Same for the 777 AFAIK

I noticed this after the update before last.

I assume it's normal since it's modeled. So, yeah. You're not crazy, as far as we know ;)

As always, check trim setting before takeoff otherwise the required control input is very large.

3 hours ago, roi1862 said:

I noticed that while rotating on the PMDG 738, the nose coming up super easy at first and then its like almost stops and i have to apply almost 2 times more back pressure to make it finally leave the ground.

Is that a Boeing feature or something else i am missing ?

On Boeing aircraft (including the 737), there is a deliberate elevator feel and control-force characteristic around rotation. As rotation begins, there can be a region where additional yoke movement produces relatively little change in pitch rate. It is designed to prevent over-rotation and tail strikes.

During rotation and aft pressure is applied, there is a slight lag before the nose begins to rise, and once the nosewheel unloads, pitch rate develops progressively. Next, control forces increase smoothly with pitch attitude. We target the rotation rate: approximately 2–3° per second for an initial target pitch 15° nose-up. All this is stable and smooth, I would not call it dead band, perhaps elevator feel future. 

That issue was brought to their attention, but as usual, they completely ignored it, and here you have it.  

1 hour ago, LRBS said:

On Boeing aircraft (including the 737), there is a deliberate elevator feel and control-force characteristic around rotation. As rotation begins, there can be a region where additional yoke movement produces relatively little change in pitch rate. It is designed to prevent over-rotation and tail strikes.

During rotation and aft pressure is applied, there is a slight lag before the nose begins to rise, and once the nosewheel unloads, pitch rate develops progressively. Next, control forces increase smoothly with pitch attitude. We target the rotation rate: approximately 2–3° per second for an initial target pitch 15° nose-up. All this is stable and smooth, I would not call it dead band, perhaps elevator feel future. 

That issue was brought to their attention, but as usual, they completely ignored it, and here you have it.  

Best explanation possible!

The rotation modeled on the 737NG is not correct on any level.

5 hours ago, roi1862 said:

I noticed that while rotating on the PMDG 738, the nose coming up super easy at first and then its like almost stops and i have to apply almost 2 times more back pressure to make it finally leave the ground.

Is that a Boeing feature or something else i am missing ?

This is not a Boeing feature. It’s a poorly modeled rendition brought to you by PMDG unfortunately.

2 hours ago, LRBS said:

On Boeing aircraft (including the 737), there is a deliberate elevator feel and control-force characteristic around rotation. As rotation begins, there can be a region where additional yoke movement produces relatively little change in pitch rate. It is designed to prevent over-rotation and tail strikes.

During rotation and aft pressure is applied, there is a slight lag before the nose begins to rise, and once the nosewheel unloads, pitch rate develops progressively. Next, control forces increase smoothly with pitch attitude. We target the rotation rate: approximately 2–3° per second for an initial target pitch 15° nose-up. All this is stable and smooth, I would not call it dead band, perhaps elevator feel future. 

That issue was brought to their attention, but as usual, they completely ignored it, and here you have it.  

51 minutes ago, ahsmatt7 said:

This is not a Boeing feature. It’s a poorly modeled rendition brought to you by PMDG unfortunately.

& @Stearmandriver

I’ve read that the iFly handles better in general.

How does it do in this and similar situations?

3 hours ago, ahsmatt7 said:

This is not a Boeing feature. It’s a poorly modelled rendition brought to you by PMDG unfortunately.

I assume you mean the ease at which it initially rotates? I do not experience the "sudden stop" in rotation described by roi1862.

8 hours ago, UrgentSiesta said:

& @Stearmandriver

I’ve read that the iFly handles better in general.

How does it do in this and similar situations?

I can't add much to what @LRBS and @ahsmatt7 have said. As they explained, there is an initial elevator feel resistance to start the rotation, and there is also an aerodynamic "dead band" about halfway through the rotation when the horizontal stab enters the area where airflow is partially blanked by the wings, with the mains still on the ground.

But LRBS nailed it - the key here is that this all happens "stable and smooth". That's exactly right. There are no abrupt transitions in feel, and while a 73 is not a "heavy", it's still a heavy airplane at 180,000 or 190,000lbs gross weight (Max9s). You feel that inertial, the plane is a very stable platform, and nothing abrupt or jarring happens.

PMDG simulates these effects but as noted, they just don't end up feeling much like the airplane. You feel as if you can tell when you've hit an abrupt coded transition, where "elevator feels like this, and then it feels like that.". It just doesn't end up working very well.

"Stable and smooth" really sums up everything I like about the iFly flight model compared to the PMDG. It's extremely smooth, and you feel as if you're controlling a stable platform with some intertia behind it - which is how airliners fly.

As LRBS and I were discussing, there are a few exceptions in 2024 right now where the iFly all of a sudden can be affected too abruptly by a gust or wind shift. It doesn't happen very often, but I notice it because of how it contrasts with the normal feel. I've confirmed that zero FDE changes were made to the aircraft for the SP1 update, so what we're seeing is related to how the 2020 flight model occasionally is at odds with 2024 physics. It'll be addressed in the 2024 native version; it's the reason they were careful to stick with the "experimental" tag for 2024. I only find I notice it maybe one time in every three or four flights on average so it's not too bothersome to me in the meantime, but it probably depends on the conditions you usually fly in. All my simming is done pretty late at night for instance, and I leave live weather on, so I'm sure I'm seeing less thermals and gusty winds than some others do.