Hard Landing?

[divinglyc]

Hi! May I ask what this gauge means and how to use or interpret it?

Thanks!

 

[Peter Clark]

I believe it shows the touchdown FPS of the last number of recorded landings. Cycle through them by clicking the button.

[Pils]

Note quite. It shows “delta G”, i.e. difference between gravity and the G load on the aircraft at touchdown, which is determined in a slightly complicated manner. It’s used to determine when an inspection of the landing gear is required. But we know how simmers love to chase butters…

Edited January 27, 2022 by Pils

[divinglyc]

5 hours ago, Pils said:

Note quite. It shows “delta G”, i.e. difference between gravity and the G load on the aircraft at touchdown, which is determined in a slightly complicated manner. It’s used to determine when an inspection of the landing gear is required. But we know how simmers love to chase butters…

Thanks a lot! So what is the appropriate range of that value?

[Pils]

32 minutes ago, divinglyc said:

Thanks a lot! So what is the appropriate range of that value?

At MLW anything below around 0.9 G would be considered “normal”.

[divinglyc]

21 minutes ago, Pils said:

At MLW anything below around 0.9 G would be considered “normal”.

Thanks a lot!

[Graeme_77]

Now don't ever press that button, or you'll end up ruining your landings! ;-)

 

[divinglyc]

1 hour ago, Graeme_77 said:

Now don't ever press that button, or you'll end up ruining your landings! ;-)

 

Haha! I have been using a Landing rate monitor plugin, so I guess I am fully prepared for facing it!

[Graeme_77]

It doesn't really show that though. As an example, if you rotate the main gear into the ground a lot of the cabin G "feel" is coming from the wings right down to the point of contact, so the HLIS won't show a high value, even though it would feel nasty to the passengers.  In the opposite sense, holding off then "rolling it on" by reducing the pitch attitude slightly will read higher on the HLIS (as the gear is taking more of the load) but would feel better for the passengers.

In short - HLIS is a maintenance tool - not a landing rate / feel monitor.

[divinglyc]

4 minutes ago, Graeme_77 said:

It doesn't really show that though. As an example, if you rotate the main gear into the ground a lot of the cabin G "feel" is coming from the wings right down to the point of contact, so the HLIS won't show a high value, even though it would feel nasty to the passengers.  In the opposite sense, holding off then "rolling it on" by reducing the pitch attitude slightly will read higher on the HLIS (as the gear is taking more of the load) but would feel better for the passengers.

In short - HLIS is a maintenance tool - not a landing rate / feel monitor.

Thanks for your explanation!!  

[RonMont]

On 1/28/2022 at 7:54 AM, Graeme_77 said:

Now don't ever press that button, or you'll end up ruining your landings! ;-)

 

No chance of me touching it...

Can't even find it LOL