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[r7377] Aircrafts and Hangars problem

Started by alexglitch, November 25, 2014, 09:34:14 AM

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Running Simutrans nightly r7377, Pak128 SVN version r1500 with modified steam engines (everything else is vanilla). Windows 8.
For some reason, the entire airplanes section is behaving weirdly, not prioritizing runways and outright refusing to enter the hangar. Crudely demonstrated by the image in the link below.
Pic 1: testing this using 2 air ports with 2 runway each, one has 4 parking zones and the other has 2 parking zones, 1 hangar and 1 controller tower

Pic 2: buy 5 airplanes to test this bug. Set a schedule to go from Wakefield 1 to Wakefield 2

Pic 3: First problem - all planes takes the right lot and rightmost runway. Left lot and runway left unattended.

Pic 4: Second Problem - after moving from Wakefield 2 to Wakefield 1, all of the planes attempted to land from the rightmost runway to a single parking lot. the rest of the lot as well as the leftmost runway is left unattended.

Pic 5: Same problem described as pic 4

Pic 6: At this point, I put a plane to the depot. the plane finally takes the left runway in the next pic.

Pic 7: Final problem - the plane refused to leave the runway and enter the depot.

Pic 8: Let's try to remove all the other routes.

Pic 9: To the final destination: the depot.

Pic 10: And the plane says it can't find a route there. At this point, the only way to remove the plane is to retire it.

So, where did everything go wrong?


This is normal behavior. Airports require a bit of planning thought in terms of vehicle behavior.

First problem: To selecting the same apron/stop tile, the planes have just left the depot and will not choose an apron/stop tile but go straight to the scheduled one. This is to avoid filling an airport with a load of planes for anew line, that then lock up the airport because they've taken all the aprons/stops. For take-off, the planes are choosing the runway closest to them to take off. This is normal because they're coded to choose the "shortest" (in this case the northern (rightmost) runway) route they can find.

Second problem: This is simply the planes choosing the shortest route again, and all have chosen the nothern runway because they can get to the apron/stop. The left runway is ignored because it's a longer journey. Planes don't check for blocked runways until they actually get there, because if they did, they would rarely ever take off because usually runways often are in use.

Final problem: The plane refuses to enter the depot, because the plane wanting to enter the runway is blocking it.

I have made a solution to your issue, using One-way Runway Signs. These work like other one way signs and the planes should then arrive on one runway and leave on the other.


+1 with Spenk009

one-way runways signs are mandatory as soon as you have more than 2 aircraft(not lines, aircraft) serving a single airport.  There are many different ways to put them, but you'll get clogged if you don't. As soon as (1) there is a dedicated landing way & a dedicated take-off way and (2) there is enough parking for all planes waiting for passengers, your airport should be running smoothly.


Thanks for the help! However, after further observations, more interesting notes arise:

- The number of parking lots should be equal (or larger) than the number of TYPES of plane you have. Since the same type of plane have the same speed, they will space out evenly during taxiing, taking off and landing, using 1 lot if it requires no loading time (while different types of planes have different speed, so they will have to reserve a different lot if a slower plane have not left the intended space.). So unless you have a fleet of C130s waiting to be filled with crates of goods, 3-4 lots should be (theoretically) enough for even serious airports.

- Planes only utilize 1 pair of runways, 1 for take off and 1 for landing (and that is with 1 way signs). Even when the airport have spare runways, they still don't utilize it (See pic). The loitering around distance might offset the distance saved here. (Also a tip in case you haven't heard it: planes always take off and land in the same direction, so put taxiways accordingly to minimize time on runway - see pic)

- Planes still can't enter depot, even when it is the only plane in the entire map. It just waits for clearance indefinitely, and if tampered with the schedule, it will refuse to respond.


The difficulty entering depots is new to me. Maybe they're just unhappy with being sent to a depot when on a runway.

Can you post a screenshot of your line configuration? This might explain why the planes choose their runways. Also, play around with the month wait time in the schedule management and see whether parking the planes at an airport for a longer time makes ones setting off from the other airport firgure out a new apron/stop.


Reset the test, new layout

Line config:

Result with load time enabled:

The planes always choose the lower runway set, and will loiter when it is occupied. Also, setting the plane to go to the depot while flying also locks it on the runway just like the image from last post. Strange


Use 1 way signs to force certain runways to be landing/take off only.

You need more landing runways than take-off runways due to the disparity in queuing efficiency. I find it efficient to have 2 functional units sharing a common take-off runway.

You can build 1 way signs at intersections (or at least could still in the RC). You just need to make the sign first before making the intersection.


I should probably cut down to the most important questions right now:

A) Why can't my plane get into the hangar? When I try to force it while flying, it goes to the runway then stands there (waiting for clearance). When I try to force it while it's on the ground, it goes to the hangar, bounces right back, continue the schedule for another round then occupy the runway.

B) Should plane pathing be more optimized? Currently it ignores an entire runway, loiters around instead of landing at a different runway and costing money.


You can at least unlock a runway by the b tool, i.e. click b until a singal appears. Click on the blocked runway should clear it.

The plane may be also be confused because it has the same tile twice in it schedule. However, a step by step instruction or a savegame may help further to localize this bug.


Save file is here. The planes are exactly like in the last picture.

unblocking the runway only allows the loitering plane to land into the plane waiting on it. The planes on the runways are unaffected.

Also, does a modded game creates a modded save file? (i.e. Do I need to add the extra PAKs along with the save file)


Ok, the planes were using depots as a waypoint only. Next nightly should fix this.

I could not reproduce planes being stuck on runway though. Apart from the behaviour that is intended, i.e. waiting for a free stop.


Quote from: alexglitch on November 25, 2014, 09:34:14 AM
Running Simutrans nightly r7377,

Pic 7: Final problem - the plane refused to leave the runway and enter the depot.
I found this problem also in 7353 - that planes achieve depot - but then they go back to loading bay.

Chybami se člověk učí - ale někteří lidé jsou nepoučitelní


The nightlies contain already the fix for this.