✈️ How SimFly Analyzes Your Landing — Community Review

[Karim-CTO-SimFly]

Hi everyone,

as promised, I’m opening this discussion to review together how SimFly currently analyzes a landing.

Over the last few days, I have reconstructed and documented in detail the current logic behind the Landing Rate, bounce detection, G-Force, Wind Bonus, and the final Landing Score.

The current logic dates back to the early stages of SimFly and has remained at the core of the landing analysis ever since.

Now I want to show you how it works as transparently as possible and discuss it with you before deciding whether anything should be changed.

I am not starting from the assumption that something is wrong.

Why I am opening this discussion

Over time, you have raised several questions about how SimFly evaluates landings.

For example, there have been cases where, on the exact same flight and in the exact same simulator, SimFly showed a different Landing Rate from another ACARS:

SimFly: -400 FPM
Another ACARS: -100 FPM

But I have also received questions such as:

“I don’t think I bounced, so why did SimFly detect a bounce?”

“Why does a bounce penalize my score this much?”

or:

“Why does a low Landing Score affect my rewards even if the rest of the flight was performed well?”

These are exactly the kinds of questions I want to address.

There is no single ACARS standard that requires every system to turn simulator telemetry into one Landing Rate in exactly the same way. The simulator provides the underlying telemetry, but each system may choose different variables, sampling moments and processing rules.

Two ACARS monitoring the same flight may therefore treat multiple contacts differently or use different averaging, filtering, sampling, or touchdown-selection logic.

For this reason, a difference such as -400 FPM versus -100 FPM, by itself, does not yet tell us which method represents the touchdown better.

Before simply comparing the final numbers, I want to show you how SimFly currently arrives at its result.

What I want to evaluate together with you

One of the main questions is whether the way SimFly currently determines the Landing Rate is the method we want to keep.

Imagine this example:

First touch: -180 FPM
→ bounce
Second touch: -420 FPM

SimFly currently applies a specific logic to the data available to it.

The attached technical document explains exactly how that logic works today.

Do you think the way SimFly currently determines the touchdown/Landing Rate is correct?

If you think it could be improved, how would you design it instead?

If you have a completely different approach, please feel free to propose it.

What about bounce detection?

This is another fundamental part of the discussion.

In the current code I reviewed, a bounce is not identified through one universal physical rule based on all wheels leaving the ground, a measured maximum bounce height, airborne time, and then a new touchdown.

The method depends on the simulator path.

On MSFS, the current logic infers bounces from changes in the touchdown values available to Analyzer.

In the X-Plane/generic path, the logic also uses a low-altitude rise condition (groundAltitude <= 3) together with the separation of data groups.

Today, the system does not calculate as dedicated bounce parameters:

• maximum bounce height;
• actual airborne duration;
• whether all wheels left the ground;
• the individual severity of every re-contact.

So I would also like to ask:

Do you think the current bounce-detection logic is appropriate?

If not, how should a bounce be defined?

Height?
Airborne time?
Wheel state?
Vertical speed at re-contact?
Severity?
A combination of several factors?

From Landing Rate to Landing Score

The FPM value is only one part of the final evaluation.

The standard Landing Score currently considers mainly:

• Landing Rate
• G-Force
• Wind Bonus
• Bounce penalty

TAS, Ground Speed and Bank Angle are displayed, but they do not directly contribute to the standard Landing Score.

Sideslip currently has no effective weight in the final score.

Very soft landings are also worth discussing: the current formula does not simply follow the rule “lower FPM is always better.”

The attached document contains the complete scoring curve and numerical examples.

The Flight Analysis Score and the Landing Score are separate values, but the Landing Score is later used in some parts of the reward calculation.

So another question I would like to discuss is:

How much should the quality of the landing really matter compared with the rest of the flight?

Technical document attached

For anyone who wants to seriously review the logic, I am attaching a complete technical document.

It includes:

• data flow;
• simulator-specific behavior;
• touchdown selection;
• bounce detection;
• formulas;
• Landing Rate scoring curves;
• G-Force;
• Wind Bonus;
• weight-related logic;
• penalties;
• final Landing Score;
• numerical examples;
• reward impact;
• known limitations;
• what has been verified in the code;
• and what still requires runtime verification before it can be considered confirmed.

I would therefore ask you to review the document as a whole before reaching a conclusion.

The main questions I would like your feedback on are:

• Is the current way SimFly determines the touchdown/Landing Rate appropriate?
• If not, how would you design it?
• Is the current bounce-detection logic appropriate?
• How should a bounce actually be defined?
• Should height and airborne time matter?
• Should the severity of each re-contact matter?
• Should FPM and G-Force refer to the same touchdown event?
• Does the current Landing Rate scoring curve make sense?
• Should an extremely soft touchdown be penalized?
• Is aircraft weight being used appropriately in the scoring model?
• Do G-Force, Wind Bonus and bounce penalties have the right weight?
• Should TAS, Ground Speed, Bank or Sideslip influence the result?
• Is the final Landing Score constructed appropriately?
• How much should landing quality affect rewards?

You do not need to answer every question.

Please focus on the areas where you have the most experience.

And if you think an important parameter or an entirely different approach is missing, please propose it freely.

If you need more information, ask me

This is an important part of the discussion for me.

If the attached document does not contain enough information to evaluate something properly, please ask me.

If you need to understand where a particular value comes from, what the Client does with it, how Analyzer behaves in a specific scenario, or if you would like additional examples or comparisons, I will try to retrieve the necessary technical information and add it to the discussion.

The goal

I am not opening this discussion to prove that the current logic is wrong, nor to defend it simply because it is what SimFly uses today.

I want to show you how SimFly actually works today, listen to the people who use it, and understand together — with as much information as possible — whether there is a better solution.

If some parts already work in the best possible way, they will stay as they are.

If better, coherent and technically feasible ideas emerge, I will be able to evaluate and test them.

Thank you all for your help.

Attachment: SimFly Landing Analysis — Technical Appendix

SimFly_Landing_Analysis_Technical_Appendix_EN_FINAL.pdf (520.9 KB)

If you have reached your own conclusions or have a different technical approach in mind, feel free to share it directly in the discussion. You can also attach a PDF or another supporting document if that helps explain your reasoning more clearly.

[shill]

I have already spend to much time on this subject in the past. Initial system was total disaster but upgraded (current one) brings some new issues as well. Methodology for landing seems almost to scientific here. 3 comments / suggestions.

1 . Taking plane weight into consideration - often people do not fly the aricraft that is used in the system - so the weights are different / off anyway.

2. Softer landings are penalized to harshly. It is very common especially form T1-T2 and even T3 planes to land a little bit on soft side
   it is not ideal landing, BUT deducting 60% or more of income for this is just a token sink and it seems to be unfair.
   just make it differently (suggestion)

• 80fpm is correct (still questionable) anything below is lowering down score with every -20 drop
• 40-80fpm should not have penalty
• 0-20 - total greaser - it can still happen for GA planes in very windy conditions - but then any landing is good…

I would drop this penalty completely as it does not make much sense in many use-cases.

if you would insist make lower down the hit

• 0-20 >>> -10%
• 20-50 >>> -5%
• 50-80 >>> no penalty

3. Bounces - if you fly with real weather and its difficult one a light bounce can happen. I would say if G force is not 1,5> 1st bounce should not be penalized (its not slamming the runway in this case).

[Karim-CTO-SimFly]

Thanks Shill, this is exactly the kind of feedback I was hoping to get from this discussion.

First, about the “almost too scientific” part, I’d like to understand a bit better what you mean. Are you mainly saying that you would prefer a simpler and more straightforward scoring system, or do you think there are other parts of the current logic that may not represent the landing well in certain situations? I’m asking because those are two different issues: one is about scoring design, while the other could point to a technical behavior worth checking.

Regarding your first point about aircraft weight, I looked into this more deeply to make sure I understood how the current system works.

The Landing Rate Score does not use a fixed aircraft weight taken from the SimFly aircraft database. Analyzer uses the total_weight coming from the flight telemetry.

So, for the Landing Rate Score, a SimFly-recognized aircraft and a Generic aircraft use the same weight-based logic if the telemetry reports the same actual weight.

The Generic status does affect other aircraft-related rules and rewards, but it does not select a different Landing Rate scoring curve.

If you were referring to a different weight-related situation, please give me an example, because I’d like to understand exactly what you have seen.

Regarding very soft landings, your point is very clear and I think this is one of the most important areas to discuss.

I agree that “lower FPM” should not automatically mean “perfect landing”. Trying to achieve an extremely soft touchdown is not necessarily the best landing technique, so I think it makes sense to keep the concept of an ideal range.

The real question is how aggressive the penalty should be when the touchdown falls below that range.

The ranges you suggested are interesting:

• 50-80 FPM: no penalty
• 20-50 FPM: reduced penalty
• 0-20 FPM: a stronger penalty, but still much lower than the current one

I’m not saying I will use those exact values, but they are a very useful concrete reference to compare with the rest of the community feedback.

What I want to avoid is a very soft landing, which may still have been well executed, having a disproportionate impact on the overall result and rewards.

Your bounce suggestion is also interesting.

Today, the Landing Score penalty mainly distinguishes the number of bounces, not their severity. One bounce applies one penalty, while two or more apply a larger one, but there is no real classification such as “light bounce” versus “hard bounce”.

Your idea of using G-Force at re-contact to distinguish a light bounce from a harder one is definitely worth evaluating.

The 1.5 G threshold you suggested can be a useful reference, but before choosing a specific value I’d like to compare it with the rest of the community feedback.

So I’m noting your three main points like this:

• regarding weight, the current Landing Rate logic already uses the flight telemetry weight rather than a fixed database weight, but I’d like to understand if you had a different case in mind;
• the penalty for very soft landings may be too aggressive and is worth recalibrating;
• bounce scoring could potentially consider G-Force at re-contact, not only the number of bounces.

Thanks again. I want to collect more feedback before changing anything and see whether a common direction emerges, but your suggestions are very useful and concrete.

[metrocat]

Hi, based on three main points you captured from Shill’s, until the first one is clearly understanding, I agreed with the latter two matters that:

Penalty for very soft landing is a bit too aggressive, and if it can be recalibrating to a range step, would be better than current one, which decrease by the number of value. But it should not be too easy, because forcing to land in a very soft FPM is much easier than control it into the desired range.

Bouncing detect by a second touch using G based is sound promising. This should reduce the false detection from a wheel ripple (for some aircraft with physical wheel shape/design), also runway slop angle.

I would like to add that, for wind bonus, will it be possible to detect the wind before the runway at some distant and include it in the wind bonus score? For example, there is a gust, cross wind along the way say, 400 to 100 feet while approaching the touch down, this situation result in more difficult to approach the landing. Then at the runway surface, the wind became dying down but the pilot is already lost the precise landing due to earlier wind situation and need the quick remedy. Therefore, if you could take this kind of bonus into consideration, would be great. Thank you.

[shill]

Ok if it takes actual weight from airplane used then its fine.

remaining two here is what i think (well they are my suggestions but still)

“Those are great changes, beautiful changes. People who know things said they are great changes and I agree with them”

[Karim-CTO-SimFly]

Thanks Metrocat. I agree with your first two points, and I’m already collecting them together with the other feedback. Thanks for sharing your opinion, it gives me some additional confirmation.

Regarding the Wind Bonus, I understand what you mean. Gusts or crosswind during the final 400-100 ft can make the approach much more difficult even if the wind decreases shortly before touchdown. I’ll check what wind data we have available during that phase and whether we can take it into account reliably.

Some very interesting common points are already starting to emerge.

[antonio.ferrara]

1. A+ for the effort that the SF “team” has by never giving up on making things better.
2. the “landing topic”. many interesting ideas. Weight of the plane. As I read about: “often people do not fly the aricraft that is used in the system - so the weights are different / off anyway.” Well it can be considered to update or review the way XP/PAX are given to those that don’t fly aircraft that are not in the SF system. I mean, why should SF give out the same rate of XP or pax to those that fly military aircraft, helicopters or any other aircraft not in the SF database at the moment? ( I always behave in the way that there are “rules” to be followed, even though those rules can change in the future, but until then I follow the rules. If I don’t agree with those rules, I can point out the reason why and wait for eventual change.)
3. Wind or meteorologic event. Am I the only one that verifies often, if not always, the meteo conditions are different, and don’t match, between what the SIM gives out and what is tracked by SF in the final log? Simfly takes into account the wind on the ground at touchdown (coming from simconnect data linked with the aircraft and obviously not the real LIVE weather conditions , but that value is not so important in my opinion, that type of wind doesn’t effect the way you approach. Winds above ground are important, maybe from 10ft to 100ft during the approach are important to determine the correct landing alignment. Also I have pointed out to SF that maybe instead of an arrow showing the direction, it would be easier to understand the wind direction, if there was a numerical number in degrees. So, if the wind (above ground) cannot be evaluated for eventual points given, maybe is better to not consider it for the final score.
4. I rather would reward a good TDZ (touchdown zone/point) on the runway instead of all the variety of FPS speeds taken into account. I mean if SF can read the weather conditions, lets say if it is raining or not, then it can be considered “safe” to land with a “hard landing” or “firm”, otherwise if the weather is clear and good, a soft landing , close to “0” is NOT dangerous. By the way, considering also that in order to have a soft landing, in most cases you overtake the optimal TDZ, and “eat” a lot of runway, thus not making a “good landing”, that’s why I consider the TDZ more important.

5. about G force also to consider different types of aircraft

At the end, I would enjoy to reward a flight that has made a correct fuel calculation, the type of flight made such as a VFR with no autopilot engaged for even 1 hour should have a more bonus than an IFR flight of 5 hours or more with autopilot engaged the entire flight. (talking about “bonus”, a plus on the usual XP points). These sort of things should be valuated more.

[Karim-CTO-SimFly]

Thanks Antonio, very detailed feedback.

For Generic/unsupported aircraft and the idea of XP bonuses linked to the type of flight, fuel planning, manual VFR flying, and so on, I would prefer to discuss those in a separate topic. Here I’d like to stay focused specifically on the Landing Score, but thank you anyway for the suggestions.

For the Wind Bonus, I’ll do a deeper review to understand exactly what data we have available during the approach and how reliable it is. If the data is not reliable enough, of course we’ll need to take that into account before using it in the scoring.

For wind direction, I agree: we can also add the numerical value in degrees in addition to the current visual representation.

Regarding the Touchdown Zone, I had already considered this. My concern was giving too much importance to the touchdown point and allowing, for example, a perfectly placed but very hard landing to still receive a result that is too high. That is why I initially decided not to use this approach. What I will do is review how much weight FPM and touchdown position currently have and see whether there is a better balance between the two.

The point about weather and runway conditions is also valid, but it opens a much more advanced part of the system. First I want to verify exactly what data we have available and how reliable it is, especially regarding the actual runway conditions. In the meantime, I prefer to focus on reducing the penalties for very soft landings, as also suggested by the other users.

Finally, regarding G-Force: today SimFly uses the same curve for GA aircraft and airliners. It makes sense to differentiate between these categories, so I will look more deeply into which curves and thresholds should be used correctly. For military aircraft, helicopters, and other types, I would prefer to address that when they are actually supported by SimFly.

Thanks again, there are several very useful points here.

I think I have received enough feedback now to start working on some possible changes. Over the next few days, I will propose some solutions based on what has emerged from this discussion and, if we agree on the direction, I will proceed with the changes.

Of course, the topic will remain open. If anyone wants to add more feedback, examples, or suggestions, you are absolutely welcome to do so.

[metrocat]

@Karim-CTO-SimFly

Regarding the Touchdown Zone, I had already considered this. My concern was giving too much importance to the touchdown point and allowing, for example, a perfectly placed but very hard landing to still receive a result that is too high. That is why I initially decided not to use this approach. What I will do is review how much weight FPM and touchdown position currently have and see whether there is a better balance between the two.

Hi Karim, I would like to address about touchdown position that you would review. Currently, there exist a different touch down coordinate/position among the SIMs and also the spot recorded on SF. For example: Some airports, both MSFS and XP, the aiming point on a runway can be different, maybe it is from the default map used or add-on scenery, and when test landing exactly on the aiming point, the result marked on SF is also not the same as appear in the SIM (in some cases, Volanta marked on another spot from the SIM too). And this happens on many airports and on some runways, not all.

Therefore, if you will take a touchdown position into calculation, it might be result in deviation and hard to control since the reference point is differ from SIM by SIM and airport by airport, so I just want to FYI you, that’s all. Maybe you can focus just on FPM for the first phase if you wish.

Best Regards.

[Kyndra]

TL;DR - If I land exactly where I’m supposed to and the landing is butter smooth, I expect a high landing score.

Lot’s of great feedback here. I just want to add my voice to the chorus of users calling for landing in the touchdown zone and on centerline to be a significant factor in the calculation and smooth landings to not be penalized (or at least significantly reduce the penalty).

[antonio.ferrara]

If the touchdown zone is not so reliable, than automatically the T&W missions are useless more than 50% of their point, as the results take into account the distances from threshold, and long, lateral deviation. You can set a “mark” but if that mark does not corresponds to the one the pilot see while landing, is useless.

Anyway

Right now, the SimFly Client heavily weights pure Landing Rate (80%) and G-Force (20%). While the formula wisely penalizes overly soft or overly hard touchdowns, it still allows a pilot to “cheat the system” by extending their flare, floating deep down the runway, and walking away with a great score and higher PAX/XP rewards. In real commercial operations, floating past the Touchdown Zone (TDZ) is incredibly dangerous and leads to runway overruns.

Instead of the 80/20 split, let’s implement a system that penalizes “bad” flying and rewards landing exactly where the airport operator wants you to land.

using perhaps a different logic could be useful if can be done of course.

1. Fixes the “Touch & Win” and Airport Economy Balance: Because airport owners in SimFly benefit from traffic, introducing touchdown zone telemetry ensures pilots respect the actual runway limits of smaller or shorter airports. A pilot trying to land a Boeing 737 on a short runway won’t be able to “cheese” a high score by floating—they will have to go around or take a heavy precision penalty.
2. Dynamic UI Text (Gamification): Instead of just showing a raw number, the SimFly flight report could award fun telemetry tags based on performance profiles:
   • “The Captain’s Choice”: High precision, sweet spot FPM, perfect centerline.
   • “The Butter Chaser”: Soft FPM (-20 FPM) but a severe penalty for landing 3,500 feet down the runway.
   • “Carrier Qualified”: Perfect precision on the aiming point, but a firm plant (-280 FPM).
3. Crosswind Leverage: The “Wind Bonus” should actively multiply the Precision and Centerline score rather than just the FPM score. Managing a severe crosswind requires keeping the plane on the centerline, not just landing softly.

this would also mean a different approach within different aircraft categories.

[shill]

There is a procedure on long runways to land not on TD zone (smaller GA planes can do that if requested and approved by ATC) - especially when parking spot is far away if they land short and have to occupy runway for longer time than necessary.

So hold your horses that it is always the decisive factor champs

[antonio.ferrara]

Obviously there are “tons” of exceptions , if “we” would consider them all, I doubt we can start something..maybe just to consider the main general ones avoiding to care about every single exception.

[shill]

Aiming point is only reference - that is why you have following points beyond which one you should go-around.

Its not bad landing - its still fully proper one - airlines dont punish pilots to land 300-600-1000 meters further.

Simfly is penalizing people to reduce pax income only, unfortunately its a fact (it has no educational results anyway in my opinion).

If you are after realism… what is realistic in making system that nobody flies to 80% of airports one could ask Realism is only good sometimes ?

Introducing more punishments is wrong direction - that is all I am saying we already have to few questionable rules (my first proposal)

[antonio.ferrara]

There’s has to be a method in order not to give away pax(money) for “free” or just giving out pax for just using a sim.. I don’t see as a punishment more than other games “punishes” players if they get hit. You know what, I always thought that the idea of “paying” someone for just flying a sim where 90% of the flight you use an autopilot is selfish… in my opinion the income should have come 80% when all the “internal” possibilities on trading, buying and selling assets, airport and aircraft economic systems where activated and so on, renting assets, mission accomplished, ando more..and 20% as a simple bonus for flying with non differences. Otherwise it looks like I would make an app and pay people that use it… it won’t last.

[shill]

Not sure what you are talking about - paying for nothing - its not the case here (assets are sort of expensive at least for me) - electricity bills are not for free (at least where I am coming from). Time has price as well.

Autopilot argument is pure nonsense. Its made to be used - again ask real 737 pilot to fly 3h route without autopilot they will look at you like you have some internal issues…

Second - Try to fly long haul first and see the outcome - its much better are more time efficient to fly smaller leveled planes on shorter distance which I can prove easily on number of my flights. (After 3,5h the gain is negligible on long haul and its not that worth - 4hflight vs 8h flight with same TO/LAND conditions (airports payout) is 15% different maximum.

Buying selling assets - look at all those assets on sale (way below their initial value - no one buys). Why ? because they are useless (T4 without 60% is useless as well no one will fly there).

Dumping prices strategy is irrational as well and acts against those who do that - but mathematics is difficult for some (go back to time/electricity/amortization of PC hardware).

Selling airports (virtual asset- that does not even belong to buyer - that seems like a great deal for seller).
Not to mention 20% royalty on everything - I am not criticizing it - but saying its for free is pure nonsense and no one should say it.

Economy is broken. Living breathing ecosystem is a myth. We are not discussing economy thou its whole another subject from landing scoring.

---

Comming back to landings/judgement.

Sometimes making is “better” or more complicated actually works the other direction. We went from fully broken (original scoring system) to “with some issues” - turning things upside down again most likely will not help.

[antonio.ferrara]

I wasn’t talking about assets that you buy, I was talking about flying hours, you really want to put on the same level a real life pilot that studied, that risk his and passengers life, against a person that flys on his room in front of a monitor, or those a lot of other things, such as going out or to work and returning after his real job or shopping and then land?

[shill]

No - its you who wants to make restrictions everywhere not me. Even if they does not make any sense (more strict that real flying rules).

If somebody is enjoying that PC is running 12hours while they are at work - its her/his business. Nothing I wish to change or criticize.

I would be surprised if anyone sits and stare at monitor for 12 hours (even real pilots do not do that they have shifts).

[antonio.ferrara]

I was just Saying that being “paid” or earn for the time spent on flying a not real plane has no sense to me, is just my opinion. The earning should come more on other things and not on time spent.

Real pilots are real, and for sure they don’t leave the cockpit as the simmers do.. obviously shifts cannot be made in a simulation, and a simulation, not real life, gives you the chance of flying an airplane you couldn’t fly in real world all alone..

By the way I don’t have any “power” on establishing rules in simfly..don’t worry.. you can feel safe..

Another consideration could also be that if real pilots are not penalized or receives a lower salary because he did “bad” landing, or went over the TDZ, we can also say that the same pilot doesn’t deserve a reward for making good landing or land within the TDZ.. in my my opinion landing should only increase XP points and doesn’t has to relate directly or indirectly to PAX income.

[Karim-CTO-SimFly]

A quick note to keep the discussion on track.

I really appreciate the different points of view being shared here, and disagreement is absolutely fine — that is also one of the reasons why I opened this review in the first place.

However, I would like to keep this topic focused on landing analysis and landing evaluation: Landing Rate, touchdown methodology, bounce detection, G-Force, the scoring system, and the impact that the Landing Score itself should have on rewards.

Broader topics such as the overall SimFly economy, asset pricing or sales, possible limits on flying hours, or other game mechanics are important as well, but I think they should be discussed separately so that we do not mix several different subjects into this review. We can absolutely open dedicated discussions for those topics too.

I would also ask everyone to keep the discussion respectful, even when you strongly disagree with each other. Feel free to challenge an idea, explain why you disagree, and provide examples or alternative solutions — but please try to avoid wording that could come across as dismissive or personal.

I want everyone to feel comfortable contributing to the discussion, including those who may have a completely different opinion.

Let’s continue with the landing discussion.