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samcaine
07 Apr 2008, 08:11
Apologies if this subject has been covered already, I can't find a reference to it.

Is it possible (and if it is, how?) on an airield with 2 runways to restrict the use of one of the runways to aircraft above a certain weight/size.

The scenario I'm looking at is an airfield with large military aircraft where one of the runways is far too small for those aircraft, but suitable for the smaller aircraft which share the field. When the wind is in the 'wrong' direction, or one of the heavies approaches from a certain direction it is directed to the short runway and ends up running off the end or interminable overshoots (sorry, go arounds in civilian parlance).

I don't want to deny the short runway to all types because that would fill up the longer runway resulting in more overshoots.

Any advice gratefully received. I seem to have cracked drive-through parking and limiting pushbacks, so this is the next step. :D

Cary

scruffyduck
07 Apr 2008, 08:43
It has something to do with the length of the runways - shorter runways will generally not attract the heavier aircraft. However it needs Jim or one of the other gurus to provide a proper answer

samcaine
07 Apr 2008, 09:08
Thanks Jon.

glottis
07 Apr 2008, 16:08
Cary
is this a stock airport (which one)
or one you have created, if so can you let us know the lengths/widths of the rwy's and if they are parallel or not

Ray

samcaine
07 Apr 2008, 17:13
Ray,

This is Charleston, KCHS, modified from stock with drive-through parking. When the heavies use the 'short' runway (21/03), which is 7010x150, for VFR TNGs they run off the end. I think the effect is partly an FDE issue, because they don't touchdown until well inside the threshold. I'd like for them not to use this runway at all. But KCHS isn't the only one, I'm about to start work on March AFB, KRIV, take a look at the GA runway there, you'll see what I mean. I have this issue at a number of UK airfields where the local unit flying club uses a grass runway at weekend. It would also be very useful for creating helicopter landing strips.

Cary

glottis
07 Apr 2008, 18:23
Cary
had a look at KCHS, and the xwind rwy is 3/21
so this will be the main rwy and 15/33 will never be used unless you activate the xwind rwy using Jim Vile's star method
and its unusual that traffic is using 3/21 and not 15/33 as its over 9000ft, but i have seen this before where FSX ignores the longer rwy
you could try closing 3/21 both ends and try to force them onto 15/33, if you shorten it to under 7000ft its still possible for traffic to use it, i would try closing it first to see if they will use 15/33
if you do activate the Xwind rwy you will still need to shorten it as both rwy's will be used
Jim will probably drop by and offer another solution for you
let us know how you get on

Ray

glottis
07 Apr 2008, 18:47
Cary
KRIV,
yes i see what you mean, gets better when you run "Fault finder"
the black center line needs putting back onto the rwy in the correct place and the node in the middle need connecting to the taxiway, then there's the hold shorts.........................

Ray

jvile
07 Apr 2008, 23:01
When the heavies use the 'short' runway (21/03), which is 7010x150, for VFR TNGs they run off the end. I think the effect is partly an FDE issue, because they don't touchdown until well inside the threshold. I'd like for them not to use this runway at all.

All Airports have to be anaylzed in order to try and satisfy the objective. No 2 airports are alike and there are no absolutes in FS9/FSX when trying to change the approach, runway selection and ground movement.

For KCHS you set the FP for a heavy AI Plane to VFR and that is not going to work very well for this airport. The Pattern altitude is only 1000 ft (RWY 3/21) so the AI has no ILS Approach code legtype to work with. This will cause the AI Plane to overshoot the touchdown point.

Because RWY 3/21 does not have a ILS approach code and 15/33 does then 15/33 carry's a higher weight for landing. However, your Heavy is VFR/TNG and it will land on the runway it took off from (3/21).

1. Completely close runway 3/21 by removing the start locations and checking the closed for takeoff and landing with ADE.

2. You can leave the 3/21 open and set the FP to IFR. This will force the AI Heavy to takeoff on 3/21 and then ATC will vector for a TNG to 15/33.

3. Leave 3/21 open and shorten the runway to 6500 ft. Any AI Plane that has a empty weight of 74,100lbs or higher will be sent to the 15/33 for the IFR/VFR TNG.

4. If none of these options give good results then crosswind the runways and try all options again.

5. Increase the pattern altitude to 2500 ft. The AI Heavy will fly a extended downwind vs 1000 ft pattern altitude.

6. Thinking of other options to try.

samcaine
08 Apr 2008, 03:15
Ray and Jim,

Thanks for your advice. I've aleady tried closing 21/03 and that achieved the desired result for the heavies, but GA traffic caused a number of overshoots.

I'll reduce the length of 21/03 to 6500ft and observe the way traffic react to that. I hear what you're saying regarding circuit height, I'll implement that.

KRIV is another matter. When I move on to that I'll see what occurs.

Thanks again.

Cary

samcaine
12 Apr 2008, 06:40
I wish I had more time to spare on this project, life's too short (well my wife seems to think I should have other priorities :rolleyes: ) :D

I've implemented the suggested changes, but I have a question about the runway length adjustment. Does the length that FS sees include blastpads and such, or is it just the stated length in the runway settings?

I'm having a bit of a 'mare with the drive-through parking, which works for most of the airfield and for taxying to parking spots, but some of the AI aircraft never leave those spots when it comes time for them to taxi out, they just sit there after getting taxi clearance but don't disappear as I'd expect them to if there was a problem either.

My IFR TNGs also go on eternally, they never land , but I suspect this might be as much a FP error as an airport error.

Thanks for the help guys.

Cary

Difar
12 Apr 2008, 09:33
I'm having a bit of a 'mare with the drive-through parking, which works for most of the airfield and for taxying to parking spots, but some of the AI aircraft never leave those spots when it comes time for them to taxi out, they just sit there after getting taxi clearance but don't disappear as I'd expect them to if there was a problem either.


Check your spacing between the P spot and the twy (and the spot next door). The ai equipment will not move if there is not enough clearance between the twy and the spot to transit to the active. Have at least half the total wing span, or more, between the twy and the P spot.
You may have to play around with this (depending on the complexity of the tarmac, it may be easier to adjust the P spot) in order to see the ac movement.

samcaine
12 Apr 2008, 09:41
Dave,

Thanks for that, I'll take a look, I suspect from what you say it may have something to do with the vehicle path I've placed. I'm not home at the moment (at my son's welcoming my brand new grand-daughter to the world :D ), I'll re-do that area tomorrow.

Cary

Difar
12 Apr 2008, 09:47
Congratulation on the new addtion to the family.

Another deviation in the flight plan to keep you from your final destination... eh. :laughing:

glottis
12 Apr 2008, 16:23
I wish I had more time to spare on this project, life's too short (well my wife seems to think I should have other priorities :rolleyes: ) :D

I've implemented the suggested changes, but I have a question about the runway length adjustment. Does the length that FS sees include blastpads and such, or is it just the stated length in the runway settings?

I'm having a bit of a 'mare with the drive-through parking, which works for most of the airfield and for taxying to parking spots, but some of the AI aircraft never leave those spots when it comes time for them to taxi out, they just sit there after getting taxi clearance but don't disappear as I'd expect them to if there was a problem either.

Thanks for the help guys.

Cary

Cary
blast pads are not included in the length of the rwy
so you can make them any length you like, same with the offset threshold this will only move it further up the rwy and the length doesn't change...........
another thing that will hold up AI traffic and to make them sit on a spot, is vehicle traffic, if they don't have a vehicle path nearby, the AI or even user aircraft will just sit there waiting for,
say a pickup truck, is coming to the parking spot that is next to your one, and this truck may be coming from the other side of the airport and they are going to use your apron links or taxiways that you want to use

Ray