Author Topic: London City STOL landings  (Read 1232 times)

0 Members and 1 Guest are viewing this topic.

Offline A34677

  • Prop 1st Officer
  • *
  • Posts: 22
London City STOL landings
« on: May 13, 2010, 03:49:55 AM »
Is there any way to adjust AI for STOL takeoffs/landings? I've been doing a lot of spotting at London City after installing Aerosoft's VFR London X. However, half the time the traffic lands beautifully, and as for the the other half, the traffic 'lands' too high and has to go around due to the short runway (this still occurs after 15 - 30 mins of loading and affects all types of aircraft). Is there any way to tweak this or is it fixed by FS? I have a lot of Heathrow and Gatwick traffic, so I'm not sure if this is a factor.

Also, I've added the British Airways JFK A318 flights and the DJC A318's rotate at the landing lights. I've heard that you can adjust the empty_weight values in the weight and balance section, which I have done and it takes off beautifully. But because its weight has been reduced by over half, the landing roll is awfully short. Just wondering if anyone knows of any other methods to change the takeoff/landing distance? All the other aircraft (ATR, BAe, Dash 8, Dorniers) takeoff/land like a dream, as long as they don't land too high.

Thank you!

Offline DanielDafoe

  • Turbine Captain
  • *****
  • Posts: 699
Re: London City STOL landings
« Reply #1 on: May 14, 2010, 07:28:02 AM »
I'm sure the FDE could be changed, but you may have to create a separate aircraft folder for the BA A318s because otherwise the FDE changes would affect other A318s and have them exhibiting the same behavior - which might screw up traffic flows at airports when these things use different runway exits due to the short stopping distances. But then again there aren't that many A318s out there, so it might not be a big deal to you.

Of course the BA A318s would also stop on a dime at the US end of the trip and at Shannon, which might have a knock-on effect there.

But what to change - well, there is something for an FDE expert to discuss. Maybe some braking coefficient and also maybe a drag coefficient (for departure)?
"Terrorism is the war of the poor, war is the terrorism of the rich" - Sir Peter Ustinov.

Offline venexiano

  • Turbine 2nd Officer
  • ***
  • Posts: 171
Re: London City STOL landings
« Reply #2 on: May 14, 2010, 11:32:46 AM »
I'm sure the FDE could be changed, but you may have to create a separate aircraft folder for the BA A318s

I second this suggestion - it's precisely what I have done in my setup. By creating a separate folder you also minimize any knock-on effects that could be caused by assigning STOL performance to all A318s worldwide ;D

As for the actual FDE changes, I vaguely remember tinkering with settings such as elevator_trim_effectiveness, pitch_stability and thrust_scalar among others, but I'm afraid I can't remember for sure.

Offline atco

  • AIG Dispatch Painter
  • Command Captain
  • ****
  • Posts: 3097
  • Notepad Ninja
    • ATCO Repaints
Re: London City STOL landings
« Reply #3 on: May 14, 2010, 12:22:02 PM »
Fede, would you mind posting that FDE please I would love to give it a try?
Vectors to nowhere, around nobody for no reason

Offline venexiano

  • Turbine 2nd Officer
  • ***
  • Posts: 171
Re: London City STOL landings
« Reply #4 on: May 14, 2010, 02:52:32 PM »
Sure, here it is. Again, it's the standard DJC A318 FDE with just a few, non-professional tweaks to the parameters I mentioned in my previous post. I just checked in the sim again, and she takes off & lands at LCY just fine. The take off performance could perhaps be improved a bit, but I feel it looks good both at LCY and at normal airports.

Offline DanielDafoe

  • Turbine Captain
  • *****
  • Posts: 699
Re: London City STOL landings
« Reply #5 on: May 14, 2010, 03:53:42 PM »
Thaks Fede, I'll also give it a try when I get the opportunity. If it works at LCY but is borderline, I guess that is the best compromise between LCY and "normal" airports anyway, so the FDE is probably the right one for us to use.
"Terrorism is the war of the poor, war is the terrorism of the rich" - Sir Peter Ustinov.

Offline Hornets Nest

  • Command Captain
  • *******
  • Posts: 5339
Re: London City STOL landings
« Reply #6 on: May 14, 2010, 04:27:34 PM »
Thanks a lot for that Federico.  I wonder whether you did anything similar and for the same reason, same airport and very similar livery for the E170 and E190 BA Cityflyer repaints you did ?  ;)
Best regards

Matthew

Offline A34677

  • Prop 1st Officer
  • *
  • Posts: 22
Re: London City STOL landings
« Reply #7 on: May 15, 2010, 05:13:04 AM »
Thanks Fedrerico! Just tested it at EGLC and it works like a charm. Now if only AI would learn how to fly that 5.5 degree approach..

Offline venexiano

  • Turbine 2nd Officer
  • ***
  • Posts: 171
Re: London City STOL landings
« Reply #8 on: May 15, 2010, 11:51:33 PM »
My pleasure, glad it works for you!

I wonder whether you did anything similar and for the same reason, same airport and very similar livery for the E170 and E190 BA Cityflyer repaints you did ?  ;)

I don't have a separate folder for the LCY-based Embraers, they seem to take off and land without any problems. The only thing I'm having issues with is getting them to park at the right angle in front of the terminal, especially the 190s (the 170s park correctly, most of the time).

This reminds me that I will have to check how the E190 performs at Florence, another short-runway airport where that aircraft is becoming an increasingly common sight.

Offline DanielDafoe

  • Turbine Captain
  • *****
  • Posts: 699
Re: London City STOL landings
« Reply #9 on: May 16, 2010, 07:31:36 PM »
Thanks Fedrerico! Just tested it at EGLC and it works like a charm. Now if only AI would learn how to fly that 5.5 degree approach..

I think that could only be done by rewriting the approaches to put the airplane higher up and closer to the airport, have them perhaps arriving at the IAF at 2000' and descending from there. They might adopt that really slow approach that AI often do where they're falling a bit like a leaf, low airspeed and steep descent - only trouble is getting them to arrest the descent before landing.

I'm having issues with.. getting them to park at the right angle in front of the terminal, especially the 190s (the 170s park correctly, most of the time).

That's surely just a matter of tweaking the turn-around parking nodes. I think the ability of the AI to turn properly has a lot to do with radius values, where an aircraft takes a sharp turn and then moves off the turn node and quits turning, just shuts down.

It might be that for E190s the node at the turn needs to be slightly further away from the parking spot that it might be for an E170. Of course, at City there are a variety of types using each spot so I guess it means looking for a compromise.

I have done some fiddling with an FS9 AFCAD for LCY (the Matthew Ministry freeware one) where he did IMO a good job of the turn-around parking, and I noticed that even the same AI type can park differently on 2 separate occasions - eg they park differently if they come towards the parking spot from the east or the west, governed by how sharply or not they turn into the link that approaches the terminal before the airplane executes the sharp turn. I don't know if you get what I mean, but that AFCAD and a few others bring it home to me how differently AI can behave in even similar situations. In the MM AFCAD the same parking spot can let an Avroliner and a Do328 prop park pretty normally - but that might be down to the radius I use (although standard FMAI and JBAI radii, AFAIK).
"Terrorism is the war of the poor, war is the terrorism of the rich" - Sir Peter Ustinov.

Offline A34677

  • Prop 1st Officer
  • *
  • Posts: 22
Re: London City STOL landings
« Reply #10 on: May 17, 2010, 05:34:55 AM »
Thanks Fedrerico! Just tested it at EGLC and it works like a charm. Now if only AI would learn how to fly that 5.5 degree approach..

I think that could only be done by rewriting the approaches to put the airplane higher up and closer to the airport, have them perhaps arriving at the IAF at 2000' and descending from there. They might adopt that really slow approach that AI often do where they're falling a bit like a leaf, low airspeed and steep descent - only trouble is getting them to arrest the descent before landing.

Well, when the AI tries to do that, they end up coming in too high and then miss the approach. At around 2.0 - 2.5 nm out, half the AI coming in to land are at 2000 ft. Oddly, they climb for another 300 feet before attempting that Harrier style landing which always overshoots the runway and turns into a go-around. When AI do manage to land, the approach is rather shallow but it keeps the arrivals and departures at a steady pace. Therefore it's probably best to set approach altitude lower instead?

Offline DanielDafoe

  • Turbine Captain
  • *****
  • Posts: 699
Re: London City STOL landings
« Reply #11 on: May 22, 2010, 08:48:56 AM »
Sorry for late reply, busy!  8)

The published approach for LCY puts the aircraft close in to the airport at 2000' and requires that 5.5 approach (at the western city side it is for building clearance and at the eastern suburban side it is for noise abatement). I see AI elsewhere making these "harrier approaches" as you describe them, and wondered if re-writing the approaches to put the AI close in might force them to the same behavior, but then again perhaps it won't, its just a theory.

I was there a couple weekends ago with someone from Uni, and I must admit that from the ground the approaches don't look particularly steep until the airplane is closer to the ground, although through a flight-deck window I guess things might look a lot different. There was a steep approach code posted up on Avsim a long time ago (I think) and I was watching a Citation approaching LCY (new FS computer, so I was checking things out briefly) and it was obviously high all the way down. Being a Citation, it landed just fine, although it took the last turn-off at the western end of the runway (!).

I know AI can follow some more complex approaches (eg Alaskan circle-to-land procedures) so maybe rather than an ILS there needs to be some new approach written that puts the airplane close in at 2000' and somehow forces it to pass a point close to the threshold at 250 feet after which it rounds out and lands. I don't know ADE, so that idea is for someone else to try out or dismiss!
"Terrorism is the war of the poor, war is the terrorism of the rich" - Sir Peter Ustinov.

Offline Hornets Nest

  • Command Captain
  • *******
  • Posts: 5339
Re: London City STOL landings
« Reply #12 on: May 22, 2010, 10:07:59 AM »
Quote
I know AI can follow some more complex approaches (eg Alaskan circle-to-land procedures) so maybe rather than an ILS there needs to be some new approach written that puts the airplane close in at 2000' and somehow forces it to pass a point close to the threshold at 250 feet after which it rounds out and lands. I don't know ADE, so that idea is for someone else to try out or dismiss!

I certainly wouldn't advise dismissing ILS that readily, Daniel because if ILS is present, AI will prefer that approach over anything else you might add.  So, it becomes a matter of re-writing the ILS, I guess, without having checked Jeppesen for the airport as yet.

Here's the thing:  I don't know approaches but I know ADE.  You know approaches but don't know ADE.  Perhaps we should get together and sort this out ?  (If you have time somewhere in between your multiple degrees, of course ?)  ;)
Best regards

Matthew

Offline DanielDafoe

  • Turbine Captain
  • *****
  • Posts: 699
Re: London City STOL landings
« Reply #13 on: May 22, 2010, 01:49:14 PM »
I certainly wouldn't advise dismissing ILS that readily, Daniel because if ILS is present, AI will prefer that approach over anything else you might add.  So, it becomes a matter of re-writing the ILS, I guess, without having checked Jeppesen for the airport as yet.

ILS would be important for the non-AI pilots out there (the ones that write on these forums!) because there'd be something they need to follow. I guess that at these Alaskan airports that I see mentioned in other forums there might not be ILS there to take precedence.

I read someplace that AI really just want a FAF and a heading to fly to that FAF, after that they look for the runway and position themselves to land, and the mystery of curved approaches is really just adjusting that skewed heading to the FAF so that it is optimal - bearing in mind that the AI will be vectored to that FAF and all the vector headings to the FAF course get skewed around as well.

I know that they are fake ILSs, but Richard said that once the AI gets an ILS they will fly to the FAF and just follow the approach to the runway at whatever angle the FAF requires them to use (one at 10 miles out will make a shallower approach than one 4 miles out, eg at a LOM). Where the AI gets challenged is with extremes, either of approach "kink" (a very kinked approach is harder to fly for AI) or of altitude (put a FAF 1 mile from the threshold and ask AI to cross it at 2000' will create an FDE headache if you want the airplane to land).

(If you have time somewhere in between your multiple degrees, of course ?)  ;)

I don't use ADE, so I'm not sure what I could contribute? I know the procedures to make them in principle, but haven't actually made an approach at all. I dissected the Abu Dhabi ones for the helicopters and had them explained to me by one of the Richards (I think the author one, Richard Faith) because I guess they're keen that people should learn the ropes, but its a question of time available, really.

I'm doing just 2 honors degrees, one in London (Law) and the other via distance learning with the Open University (Arts & Humanities, involving study of politics, religion, philosophy, art, art history, history, literature, classics, mythology, and even tangentially medicine etc, e.g. the Islamic concept of hospitals that was superimposed on Greek clinical practice (Humoral Medicine) and which outlived the humoral system to remain relevant even today (the Islamic medicinal system was passed back into Europe via Spain when the Moors were beaten back from Europe, and the concept of public hospitals came with it as the notion of humors was discarded). There's also useful info on referencing and questioning sources etc, so quite intense but in a different way. Its a very cool set of courses that makes world history make a whole lot more sense, everything from Plato to Stalin. Sorry if that last bit is kind tedious, but I really enjoy my work on these things.

After the Law is finished (it focuses on English and French - but also general European law) I will be going to a major US university to pass through the US system - the English course should provide some credits and get me a head start. I'll also do a Masters in Humanities with the OU while I'm home in the US (well, okay, halfway home since I'll be in the Northeast and wishing for English winters). After that, maybe I will have some freedom, and hopefully a great deal of it. Just need to put in the hard labor now.

The thing I guess that makes the "multiple" thing fit is that the OU is being studied 2 courses at a time, so I'm running the course into 3 years rather than 6 lower-intensity semesters (although many OU courses aren't six months long, but often 8 or 9). Since I can do a lot of OU work on the train rides I take, and some evening and weekend work, it fits quite well and makes the partying sweeter. I think what a lot of students at high school/college/University forget is that this small part of our lives affects the course of the rest of it, so I'm packing it all in as best I can. I'd rather these few years are gruelling while I can handle it, than the rest of my life when it gets harder to handle the consequences of not having studied well.

Over June a couple of courses finish, but early July I'm back in LA for a couple weeks (still doing a bit of OU work) and Tahiti (doing NO work) and back in the UK in August to prep for the next term, so it's a tight schedule for me. I guess I'm saying that I might not be able to put a whole lot into FS for a while, and the few things I do seem to get copied or whatever a while later, so in some ways there's not a whole lot of point in it.

If ADE allows for the placement of custom models, and someone is prepared to give me dimensions and good images of terminals, that's an area I'd be more able to help with, since I can use Gmax well enough to make terminals and LODs for them. I was also given the Gmax sources for the Abu Dhabi jetways, so anything I made would have respectable jetways too. It couldn't be a production line, but maybe one or two terminals a year seems a commitment I could meet (any more than that becomes a commitment I could fail on).

Right now I don't even have the time to set up my new FS computer!
"Terrorism is the war of the poor, war is the terrorism of the rich" - Sir Peter Ustinov.

Offline Hornets Nest

  • Command Captain
  • *******
  • Posts: 5339
Re: London City STOL landings
« Reply #14 on: May 22, 2010, 03:48:24 PM »
 ::surprise::  Mind you, I suppose anybody who can include "Tahiti (doing NO work)" as part of a "tight schedule for me" has to have a slightly odd view of life..  ;D

Quote
If ADE allows for the placement of custom models, and someone is prepared to give me dimensions and good images of terminals, that's an area I'd be more able to help with, since I can use Gmax well enough to make terminals and LODs for them.

Do you know what we need models of most of all ?  Airstairs..  Both for FSX and for FS9 - preferably 2 or 3 varieties.  The upside for a modeller is that those will not just appear at one airport, as a terminal would, but at many, many airports - in the same way as many of currently use Jim Dhaehens lights, radars and hangars.  If you can model some airstairs - could be good practice for bigger things - that would be really great...  ;)
« Last Edit: May 22, 2010, 06:44:51 PM by Hornets Nest »
Best regards

Matthew