#242 runway incursion / simulated crash + simulator crash

[Anonymous]

Originally created by: g...@av8n.com
Originally owned by: durkt... (code.google.com)@gmail.com

Just now I was operating the flagship C172 at Heathrow.

a) A large number of warning messages appeared on the console.

b) I was sitting at the initial position on runway 09R.  I had not
even started the engine.  After a few minutes a transport-category
airplane taxied up from behind and smashed into the C172.  The
C172 was flipped over and over became unusable.

c) Shortly thereafter the entire simulator became unusable.  It
appeared to be in a loop. Nothing was responding, not even the
view controls or GUI. 

Note: Part (a) and part (b) appear to be 100% reproducible.

What happens next is more variable.

I know that it is poor pilot technique to sit on the runway for
longer than necessary, because of the chance of getting hit by
another aircraft ... but it's not supposed to be a 100% chance!

============================

See the attached barf for details of version and configuration.

See the other attachment for some of the console warnings and errors.

============

It is likely that there are three or more bugs involved here.
I hesitate to speculate about the extent to which the bugs are
related or unrelated.  At this stage, all I can do is report
what I observe.

[Anonymous]

Originally posted by: gijsrooy

I was able to reproduce this with a nice wind setting (as the AI traffic picks the best runway available).

This is one for Durk ;)

Labels: AITraffic
Cc: durktals
Status: Accepted

[Anonymous]

Originally posted by: vivian.m...@lineone.net

Readily reproducible. My assessment is that AI aircraft no longer respond to conflicting traffic, and they are HOT enabled. They therefore trample over other models and cause a crash.

This seems to be a regression - AI Aircraft used to respond to traffic. Enabled HOT also causes the stacking of aircraft where there is no groundnet defined.

[Anonymous]

Originally posted by: bre... (code.google.com)@gmail.com

I've also seen this several times - especially an issue at busy airports - like EHAM. We should really fix something here for the release. At least switch off HOT, if that helps avoiding the crash.

Labels: Priority-High

[Anonymous]

Originally posted by: bre... (code.google.com)@gmail.com

(No comment was entered for this change.)

Blocking: 221

[Anonymous]

Originally posted by: gijsrooy

HOT was enabled because we had "smart" AI traffic. Now that they're dumb again, it's no longer fair to make them HOT. Disabling HOT for now seems like a good workaround IMO.

In real life you do have to watch out for traffic around you, but most pilots will not deliberately drive into you ;)

[Anonymous]

Originally posted by: bre... (code.google.com)@gmail.com

Some tests by Vivian and me revealed that disabling HOT for AI aircraft actually also makes them smart again: once HOT is disabled, they nicely wait behind when a crossing or runway is blocked. It also seems to fix/improve bug issue #221 - no more stacked aircraft visible. It's easy to disable HOT in the AIAircraft base class. We'll discuss a possible fix with Durk.

Status: Dev

[Anonymous]

Originally posted by: vivian.m...@lineone.net

Apart from A380 pilots :-). I think that disabling HOT is a complete fix for issue Issue #221. It is open for discussion if all AI Objects should default to HOT disabled. AI Carriers and AI Ships are obvious exceptions, but apart from these nothing obvious springs to mind.

[Anonymous]

Originally posted by: bre... (code.google.com)@gmail.com

Durk, here's a suggested patch. It moves the existing "disable HOT" feature from AIMultiPlayer to AIBase - and adds an option to AIBase, so each AI class can choose whether to allow HOT. As suggested by Vivian, it's disabled for all AI classes now, except ships/carriers.

Owner: durkt...@gmail.com
Cc: -durkt...@gmail.com g...@av8n.com

[Anonymous]

Originally posted by: durkt... (code.google.com)@gmail.com

Just a few quick comments for now: In general, disabling the HOT status, as proposed would be an appropriate solution for the upcoming release. With regard to the intelligence of the AI system, please be aware that the current situation is that AI traffic is currenly only semi intelligent. Other aircraft that are taxiing on the ground do respect the user controlled aircraft, but once they have shifted from ground control to tower control, this part of their intelligence disappears. I'm currently working on that issue (as part of the AI/ATC integration effort), but given my current speed of progress, I don't expect this code to be ready until the 2.6.0, or maybe even the 2.8.0 release. So, in the mean time disabling the HOT status, as proposed by Vivian would be the best approach.

D.

[Anonymous]

Originally posted by: bre... (code.google.com)@gmail.com

Ok, thanks Durk. And notice the interesting bit, that AI aircraft in fact only respect the user controlled a/c when HOT is off (for AI aircraft). So, something funny causes enabled HOT to break the user a/c detection (on the ground).

[Anonymous]

Originally posted by: vivian.m...@lineone.net

When is the patch likely to be applied? It would also be sensible to make ballistic objects HOT disabled. At the moment this is done in each model's .xml wrapper. The patch to do this is trivial, but I'm waiting for the outcome of this fix.

Labels: BallisticObjects

[Anonymous]

Originally posted by: bre... (code.google.com)@gmail.com

I've pushed the patch suggested above:
http://www.gitorious.org/fg/flightgear/commit/c19664291f3a12ab2518978d0b51a8ad52fd53b5

It resolves the issue of AI aircraft running over the user aircraft. Will need to test if that causes new issues though.

Status: Testing

[Anonymous]

Originally posted by: bre... (code.google.com)@gmail.com

(No comment was entered for this change.)

Status: Fixed