cj3737

A320 auto land speed and landing rate

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Been a long time airbus owner and have logged thousands of hours in my X.  I frequently used auto land in fsx and p3d v2 with relatively no issues..  once I got v4 and the airbus, I tried to use the auto land feature and it mostly works..  I've found it doesnt regulate speed according to the approach data in the fms so it needs to be controlled with the speed knob.  Takes a little practice and feathering of the speed brakes to get the plane down to flaps 1 approach speed but it it manageable.  The X didnt have this issue...

 

Also the landing rates are really high...  In the X, they were generally around 250 or so but in the pro model I've seen jumps to around 750.  I do have addon scenery and have done the elevation adjustments on the payware.  I get the same rates on default airports as well.  The flare indication does illuminate but its right before TD and the plane usually slams into the runway.

 

All the ils info is input and correct as it tracks pretty true to the runways on approach.

 

Can anything be looked at regarding these 2 issues?

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What aircraft?  IAE or CFM?

What are your frame rates?

Add Ons?

Weather conditions etc...

 

I just performed an auto land 250 fpm touchdown right on the center line.

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Hello,

Sorry for entering someone else post. I was actually preparing a post with exactly the same content and hope will be excused posting my material here.

I am experiencing similar landing conditions reported by cj3737 above. Landing fpms are higher with pro version compared to those when using same planes and same loads on same route in SFX:SE. I am using A320 mainly and can say that have more than 1000 hours flight time on it on Steam.

Here are my data:

- Prepar3D_v4_Academic_4.3.29.25520;

- AS_A320-A321-PROF_P3DV4;

- REX 4 - Texture Direct with Soft Clouds Enhanced Edition;

- AS_A320-A321-PROF_P3DV4, Version 1.2.1.3;

- FTX Global Base pack + OpenLC Europe;

- Flight date: 2018/10/26, flight preparation started at 07:57:08 UTC. Landed at 11:30:37;

- Flight route: LPMA/EGGD. Planned with PFPX;

- livery: G-EZTB (the original delivered with the AC);

- Departure Rwy: 23, SID: DEGU3S;

- Landing Rwy: 27, STAR: BAXU1A;

- Cruising level: FL380;

- Touched down at -525 fpm

- Full automatic landing following an ILS approach path;

- Screen frame rate: 45 - 55;

- All other flight details are attached, including Pax, Cargo, Fuel, etc.

- smartCARS version 2.1.31.0, 2018/10/26 UTC log is attached also;

 

My additional question is why following was recorded:
[08:19:50] Engine 2 is on
[08:20:25] Engine 1 is on
[08:20:25] Engine 1 is off
[08:20:26] Engine 1 is on

There was no faulty start of engine 1 at all. I had seen such question in another post also, however it was not answered.

 

Hope provided information is sufficient for analyses and would appreciate any helping feedback.

 

LPMAEGGD.zip

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Hi,

Although this topic looks like too much as a monologue, I would like to make several clarification statements, after which the Owner cj3737may wish to request closing it, if he is satisfied from the comments.

1. Most Important For me the subject got clear, which I will describe below. It was almost a week since I was working on it together with the very kind and continuous support from Hanse, member of AS Project team. I would say the following findings, if the subject should be resumed with several sentences:

- The Pro version of the Bus is using completely new programming algorithm for controlling the flight and corresponding performances. In regards to the above, it is not quite proper to compare the performance of 32 and 64 bit version of same AC;

- landing performance of Pro version too much depends on the airport equipment and has to be handled more carefully, if similar results to 32 bit version should be achieved;

- there are certain variables, which can be easily monitored and which are representing the AC performance. They will be mentioned below;

2. Why landing rates? This question applies to those of us who are using the AC as part of their flying for particular VA. The main tool, which most of the virtual airlines are using for evaluating their pilots' performance is SmartCars. The easiest way for monitoring the pilot performance is how he takes off and lands. It is another subject, if this is the rightmost one. SmartCars gives an option to monitor and record the landing rate of the AC, i.e. the vertical speed at which the plane touches the runway. This is actually a parameter, which never is monitored in the RL, however being a computer program, the facilities for recording such are there.

Most of the VA are setting their targets for what a perfect landing is considered to be based on this landing rate. The one where I am flying sets the target for -150 fpm for a perfect landing as an example. The evaluation system was made based on different ranges above and below that. All flights having a landing rate of -550 fpm and above are rejected. 

3. How is this measured? This subject is a bit complicated to explain, but I will try to use the most simplest way of saying it. There is a variable called VERTICAL SPEED, which SimConnect provides and which represents the vertical speed at any moment (most correct is on every frame) of the SIM. I promised to do this as simple as possible, so anyone who wants more details can check "simulation variables" in the SimConnect API section.

A wise Gentleman, his name is Peter Dowson, created a tool called FSUIPC, which keeps a track of this and other variables, which the SIM provides. Moreover the FSUIPC has an option for sharing these variables with other third party applications, including SmartCars. The programmers call them offsets and the one, which represents the vertical speed is 030C. The tricky part of all this is the unit of the variable, which is provided. The vertical speed provided by the SIM is 256*mps (meters per second or m/s), which is a standard unit for measuring speed. The aviation world is using fpm (feet per minute) for measuring speed, which needs some conversions to be applied (a simple formula is multiplication the m/s with 60*3.28084/256 and recording the closest integer value).

4. Some final words One of the mandatory conditions for using SmartCars is having FSUIPC installed in the system as mentioned above. It doesn't matter paid or unpaid version is used. SmartCars reads the variable from FSUIPC, makes corresponding units conversion and includes it in the log. Mr. Hanse and I did several tests, recorded different logs in different landing conditions. The conclusion is that landing performance of the AC is recorded properly and SmartCars logs are correct. It comes again to pilot's ability and skills to touch down within the required limits. Moreover, most of the airports do not support full automatic landing, which should be taken into consideration when flying.

 

This is all what I can say for the subject. I am using once again the opportunity to thank for the support received for clarifying it.

 

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On 10/27/2018 at 9:31 AM, bill3810 said:

What aircraft?  IAE or CFM?

What are your frame rates?

Add Ons?

Weather conditions etc...

 

I just performed an auto land 250 fpm touchdown right on the center line.

Mainly A320… Both IAE and CFM models

Frame rates are 30-40

Addons- Orbx global/vector FSDT and flightbeam West coast airports

Weather was what ever active sky 16 pulled at the time… I think it was pretty clear at all the airports Ive tried

KLAS, KPHX, KLAX, and a couple P3d standard airports.

 

As Goshob stated, Landing rates are judged by the VA and they aren’t really that big a factor per se, however the aircraft does seem to slam into the deck when hitting those 500+ rates. 

 

I was playing with my NGX this weekend and found my throttles may have contributed to the speed management issue on decent.  I lowered the null zone on calibration and it helped that aircraft manage speed.  I haven’t tried it with the bus just yet but I plan on checking it out. 

 

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Finally got around to flying...

Took out the 320 cfm ... did a couple touch and gos at Flightbeam KPHX.  Plane is still slamming into the deck using autoland.  Approach speed is 137, flaps full, landing ils rwy 8 with 090 @ 7 wind.  Frames at 30+ no stutters...

 

Aircraft does flare but it seems to flare just a tad late.  Seems to drive into the runway and doesnt settle into the flare.  I wasnt running smart cars so I can't specify the exact rate but it wasnt a cushy crowd pleaser...

 

Haven't tried with a stock p3d airport but I cant imagine the elevation is much different being other planes handle the landing nicely.

 

 

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1 hour ago, mopperle said:

The latest experimental version prints out a sheet which tells you the touchdown rate.

Where is that stored?

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Well I just ran a hop from Sacto to Portland in the IAE.  Autolanded at 247 fpm which is acceptable... I did notice it still didnt follow the decent path properly and had to intervene to get the plane to the planned altitudes and speeds.  Guess I'll wait for that to be addressed as I've seen others bring up the same issue...

 

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Hi Guys,

Good that the topic develops. I wish to ask a question:

Does anyone try playing with the value of Vapp in Performance page of the MCDU? It affects the landing rates, but I am unable to find a reasonable range yet.

There is a very valid statement made by RL pilots for increasing the calculated value with 3 - 5 knots in order to avoid activating emergency response (protections) of the automation in case of gusting winds during landing, sudden change of wind direction, etc. (Thanks to Mr. Hanse :) ). We may go to more deep discussions about this, but unfortunately I do not have enough theoretical knowledge in aerodynamics and would appreciate if someone comments.

 

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On 11/25/2018 at 6:59 PM, mopperle said:

The latest experimental version prints out a sheet which tells you the touchdown rate.

Recording the touchdown rate is easy. It can be done in several ways. Most important is what actions should be taken for keeping it within certain limits?

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49 minutes ago, Goshob said:

Most important is what actions should be taken for keeping it within certain limits?

As in real life: manual landing and practice, practice, practice.....

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On 12/6/2018 at 6:34 AM, Goshob said:

Hi Guys,

Good that the topic develops. I wish to ask a question:

Does anyone try playing with the value of Vapp in Performance page of the MCDU? It affects the landing rates, but I am unable to find a reasonable range yet.

There is a very valid statement made by RL pilots for increasing the calculated value with 3 - 5 knots in order to avoid activating emergency response (protections) of the automation in case of gusting winds during landing, sudden change of wind direction, etc. (Thanks to Mr. Hanse :) ). We may go to more deep discussions about this, but unfortunately I do not have enough theoretical knowledge in aerodynamics and would appreciate if someone comments.

 

Playing with Vapp may do something to help... I know the 737 in auto does a +5 Vapp but the bus barks at you if you dont set it to Vapp speed.  I'll make a hop tomorrow and see what happens if I raise it a tad...

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Flew into Flightbeam KMSP to ils 30L in the cfm.  Landed at 347 fpm...  not happy with that... raised the Vapp +5 from the initial setting... just for fun but it didnt help the landing rate...meh...

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On 12/6/2018 at 6:26 PM, mopperle said:

As in real life: manual landing and practice, practice, practice.....

"A good pilot is the one who is always learning" This is a very well known maxima from RL and does not apply to pilots only. 

However and because the author of this topic started it in a so called comparison way, may I ask a basic question? What is actually the difference between the 16 and pro version of the aircraft concerning landing performance and especially when the plane is in fully automatic mode? I was using A320 STEAM edition for more than 3 years and can say that there is roughly about 150 - 200 fpm difference between the landing rates. This comparison was made with same type of AC, same load, same airport, same RWY and same weather conditions.

There was lots of writing in one of my previous posts about this, which I do not plan to repeat. At the same time and if this was made purposely for stimulating the users to increase their qualification would be appreciated. At the same time, I am not sure if we should make such comparisons at all due to the different program algorithm used in both versions, but at the same time the AC is the same by default. Again by default the performance is expected to be the same. It is easy to reach a situation similar to flight JT610 otherwise...

Thank you! 

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On 12/8/2018 at 7:40 PM, cj3737 said:

Flew into Flightbeam KMSP to ils 30L in the cfm.  Landed at 347 fpm...  not happy with that... raised the Vapp +5 from the initial setting... just for fun but it didnt help the landing rate...meh...

 

Sounds quite believable however, especially if you did not have calm winds and zero turbulence. I was quite surprised how "bad" autolands can be in real life when I started flying airliners.

They get by far not as close to what a pilot can do. And this is still talking about calm conditions with only a couple of knots.

Keep in mind what autolands are build for: Foggy conditions with bad visibility and low cloud bases. Those are usually associted with calm winds, else the fog could not develop. If you have a very low cloud base and strong winds you would rather fly a monitored approach in real life than an autoland.

I do not want to know what it would look like getting close to the operational limitations listed in the LVP checklist in the QRH or the Limitations in the FCOM.

It sometimes really can smash it down onto the runway, a soft landing is not the goal of the system, the goal is to get the aircraft where it should be: In the touchdown zone, on speed and on centerline. And it will do everything it needs to adchieve these targets.

At the end of the day it just remains what it is: A dumb computer which has to be closely monitored by the pilots. It is not a replacement for the pilots and it'll take decades, if not centuries, until it might become one.

 

On 12/6/2018 at 2:36 PM, Goshob said:

Recording the touchdown rate is easy. It can be done in several ways. Most important is what actions should be taken for keeping it within certain limits?

 

FIrst of all make sure to use it only when it's within the prescribed windlimits from the FCOM. If there's too much turbulence I wouldn't use an autoland either, those AP's just aren't trustable enough.

If it actually deviates from the limits there is just one correct action: Go around!

(or even better: Recover manually before it exceeds the limits)

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Problem is, I did have calm and favorable conditions.  Weather was set to fair and active sky was off.  May have been a slight head wind which should've helped the flare but it landed harder than the IAE test.  There could be some slight elevation issue with the addons vs stock airports but the other makers seem to have nailed it down...  just some observations with the flight characteristics in autoland. 

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10 hours ago, Mathijs Kok said:

We now believe the aircraft is a few knots to slow in these stages, being looked at.

Excellent..  Ill keep an eye out for the update.  Ill do some VAPP speed testing of my own and let you know whatI come up with

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Just ran KRNO KSLC...453 fpm!

Stock easyjet 320 cfm...Ils 34L. 040 @ 3 so not much cross... Vapp 137 as suggested in the planning ... EFOB at dest was about 5.0...approach was stable then SLAM!

 

I also had an issue with the managed cruise speed..  was set to .75 mach in crz phase but always resorted back to 203 knots if I let the AP drive...I managed the whole flight and held as long as I didnt let the AP set speed.

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On 12/8/2018 at 10:40 PM, cj3737 said:

Flew into Flightbeam KMSP to ils 30L in the cfm.  Landed at 347 fpm...  not happy with that... raised the Vapp +5 from the initial setting... just for fun but it didnt help the landing rate...meh...

I was performing some tests during the last weekend using G-EZTB - A320. Best results obtained were on manual landing or at least without auto thrust at final stage. For me obtained values between -200 and -250 fpm are satisfactory.

Talking about all this, I would like to rise a question about the usability and importance of those landing rates. We are discussing them too much in several topics already, but they are actually values, which have no any relations with the RL operations and are only used by the VA for evaluation / ranking purposes. How correct is the usage of those rates is a different subject, which I mentioned several times that here is not the place for discussing.

Before completing my post, I would like to mention that in RL I am mostly flying with A319 or A320 recently (as a passenger). It was observed that every pilot has his own style of landing. It seems to me that the most important is if the plane meets the targets of touch down within the threshold and stops safely. All other qualifications like soft landing, semi-soft landing, hard landing, etc. I strongly feel have no value since the landing is safe and the AC is with no damages on the landing gears. (Last is very exaggerated of course).

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Not wanting to hijack this thread... but :

 

"Landing on the ship during the daytime is like sex, it's either good or it's great. Landing on the ship at night is like a trip to the dentist..."

 

and where I came from:

 

"They say in the Air Force a landings' okay,

If the pilot gets out and can still walk away,

But in the Fleet Air Arm, the prospects are grim,

If the landings' p...ss poor and the pilot can't swim"

F1000062.JPG

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I guess it's just my preference to see and "feel" a buttery, pillow soft landings.  I'm prolly also spoiled by other aircraft the perform autoland like the plane never left the ground.  I don't have an issue hand landing and can achieve my desired results but I like putting the planes thru their paces and seeing what they can do for me.   I agree VAs shouldn't base performance on landing rate but ive seem some decline a 12-18 hour pirep because of a cruddy rate.  I am a perfectionist as I assume most of us probably are and seeing a double digit rate is phenomenal...and if the aircraft can do it without me touching the stick, its all that much better...

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