Brakes causing rapid acceleration on certain hills?

[suicidejunkie]

Version 1.0.5
build id = 01028
2015-11-10_18-03-24

Fresh install, no mods.  (Save file migrated from a modded game)

http://imagemodserver.duckdns.org/nick/tempstuff/hardinfo_report.zip

 

This isn't a game-stopper for me, but it definitely is a weird physics glitch I want to report.

 

I was driving my low tech science plane around on the eastern coast of the desert continent, and using the wheel brakes to keep my speed down.

Then I reached the edge of a grass polygon and moved to a flatter area.  Except now I was accelerating out of control, up to 50m/s at which point I couldn't hold it and the plane flipped out and crashed.

I reloaded and tried again, and discovered that the acceleration was appearing only when I hit the brakes on some fraction of hill polygons.

 

The savegame below has a science plane out on the continent to the west of KSC facing uphill.

http://imagemodserver.duckdns.org/nick/tempstuff/KSP_uphill_turbo_brakes.zip

1) Switch to the science plane.  (quicksaved in the plane to start)

2) Throttle up to 100%

3) Release the brake and head uphill.

4) As you reach between the flags (Titled "No stopping zone"), cut the throttle to zero.

5) Wait for your speed to decrease as jets spool down, then activate the brakes.

6) Observe speedometer start to rapidly increase. Note: Releasing the brakes will allow the craft to slow down again due to gravity.

7) Catapult into the sky with brakes on.

8) Land safely for style points.

 

It is as if the brakes are applying a huge negative torque, but only on some ground polygons; they operate normally most of the time, so the way to survive is to pitch up and get off the ground, then circle around to a hill that is less Kerbophobic.

[Rocket In My Pocket]

I've also encountered this when trying to taxi submarines over to the ocean.

Very annoying, hope it gets fixed!

[sal_vager]

It should be moot, as the wheels in 1.1 use all new code the existing bugs won't exist.

[cubinator]

Have you made sure that your Kerbals haven't accidentally invented a warp drive instead of a brake? Sometimes when you try to use a warp drive as a brake it doesn't work. Are you sure your brakes aren't made of antimatter?