tamsini

How is landing rate calculated\?

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Hello all, as the title suggests, how is landing rate v/s calculated? Especially important it seems for virtual airlines, is it calculated from the time you begin your descent to touchdown or is there another formula?

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Generally speaking, it's the vertical speed at the exact point of touchdown - that means the first frame where the aircraft is reported as on the ground. Its fidelity varies with frame rate.

Not all virtual airlines focus solely on landing rate; others include the runway distance from the threshold which when combined with airspeed and landing rate provides a clearer picture of the overall landing.

Cheers!

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15 minutes ago, Luke said:

Generally speaking, it's the vertical speed at the exact point of touchdown - that means the first frame where the aircraft is reported as on the ground. Its fidelity varies with frame rate.

I see, Very interesting, indeed, For some reason, I thought the rate of descent played a part of it. Thanks for clearing that up, Luke!

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The VA I fly with has the following parameters for an optimal landing.

Between 100 and 300 FPM landing rate and approximately 1500 feet from the threshold.

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So as indicated above, there are different criteria for reaching the final value, which would explain why my VA does not always match the LRM tool (landing rate monitor).

Thanks, guys.

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If you can walk away from it, it's a good descent rate. If you can walk away from it and use the aeroplane again, it's an excellent descent rate. :cool:

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2 hours ago, tamsini said:

So as indicated above, there are different criteria for reaching the final value, which would explain why my VA does not always match the LRM tool (landing rate monitor).

No, there shouldn't be. Where there should be differences in the analysis of what makes a "good" landing, there's only one authoritative source for touchdown speed - it's vertical speed until the aircraft is on the ground. In the MSFS/P3D world and you're using FSUIPC, that's offset 030C which is the vertical speed of the aircraft that is updated so long as the aircraft is airborne. It's refreshed every frame, hence my comments above.

What one probably shouldn't be doing is polling the sim yourself, since that's likely to be slower than the sim's frame rate and therefore not likely to produce an accurate result. (If you're using SimConnect natively to talk to FSX/P3D, you should be subscribed to an event every frame, not 6Hz or the other options.)

Cheers! 

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7 hours ago, Luke said:

Not all virtual airlines focus solely on landing rate; others include the runway distance from the threshold which when combined with airspeed and landing rate provides a clearer picture of the overall landing.

Luke,

What are some of the VAs that provide this type data to their pilots?

blaustern

 

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Landing rates in P3D/FSX are a bit of a joke anyway and I'm not sure why it's become such a particularly important criteria.   Anyone who has flown with Ryanair will know that hard landings are the way to go. 

In sim, there is no appreciable sense of a hard landing other than intuition and some modelling of appropriate sounds.  Also, if viewed from an external point of view,  there is no appreciable spongy gear compression at all.  It looks very binary 

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36 minutes ago, Christopher Low said:

Why is this critically important for VAs? Are they that picky? :huh:

Not quite sure there is much emphasis on this. But, sure enough, most VAs, it seems, always list top-ten landings (or variations of same) in their pilots' list. So, of course, I try to get on the list. I'd sure like to know if this is even an issue with real-world pilots.

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3 minutes ago, tamsini said:

I'd sure like to know if this is even an issue with real-world pilots

This is not an issue in the real world.  As long as the landing is a safe one, no one is standing there grading the pilot on how good it was.  Trying to get the smallest landing rate possible is not a goal in real life.  But, for VA's, they I guess have to have some way to evaluate how good you are(or aren't).

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IRL, a stabilized approach and landing within the TDZE and on center line is far more important than a 'soft touchdown'.  A 3 fpm landing 3,500' down the runway is a terrible landing.

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I agree - and the continual challenge over the past few years has been determining a way to measure that. We started with vertical speed at touchdown, then we got distance from target landing zone on the runway. Some airlines are starting to include descent rate and stabilized approach although that's harder to measure accurately.

Having the "best" landing as the one with the lowest fpm at touchdown is just wrong. The VA I belong to actually has a target speed that gets combined with a target distance from threshold. It's not perfect but it's getting there.

Cheers!

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