FMC Crash - Changing Arrival STAR then changing Flight Level

[TheBlueSea]

Hey guys,

Might as well put it on here for you guys...

Mid-Flight and cruising stable.

Went to change STAR Arrival from ILS to a Visual in Canberra, Australia (from Brisbane)...

Successfully changes (although it didn't initially work due to a break in the legs...), which was rectified.

I then immediately went to amend Flight Level (flight plan turns left to head east so i wanted to climb)...

FMC stated optimum Cruise @ FL370 (currently flying FL360).

Typed FL360 into FMC and it gave me a target altitude unable warning (not sure of exact wording).

So i then put 37000 in the altitude selector and then went to change the cruise altitude in the FMC, selected VNAV...

When i pressed VNAV the FMC crashed. 

It is completely unresponsive currently and ill reboot on ground.

The picture attached is the screen the appeared immediately on crash... didn't know what to look for so i hope that helps.

Matt

 

 

 

Grab_FMCCrash_140516.tiff

[Litjan]

Thanks for the report, Matt!

The FMC shouldnt crash, period. We will look into that.

Just a word of advice about the "optimum altitude": It does not take distance to fly into account. It purely looks at the current weight (and speed, if not in ECON). So it is quite possibel that you will get an UNABLE CRZ ALTITUDE warning, even if the optimum suggests that you should climb to it.

I will try to replicate your crash - if you get another one, be aware that you can "reboot gizmo" while flying and at least you get a responsive FMC back (though you have to re-enter your data)

Jan

 

[TheBlueSea]

Jan,

Appreciate your reply so quickly... 

I might be wrong... but i swear the error on the FMC that started everything had "Target Altitude" on it... and there was approx >100NM before TOD, and only climbing 1000ft i thought it would have no issue.

 

That aside, Just completed the remainder of the flight, both by VNAV (Alt Hold) & then vectoring...

I had the console appear on the screen approx 5 times on descent and i don't believe i triggered it (e.g. 15 secs after changing heading dial)... photo's attached

And a 6th console error displayed and completely disactivated the flaps handle. Background to this was that i was pressing "2" key to lower flaps from 15 degrees to 20 degrees, and on key press, the console gave me the error. Afterwards, i observed the flap handle stuck on 15. Only after the flight landed did i notice the flap extension indicator showing the flaps were in fact extended beyond 15... to 40 degrees.

The errors in picture FMCCrash_140516_4_A.tiff were all seperate from each other by a period of time and not triggered simultaneously (a minute or two).

 

FMCCrash_140516_2.tiff

FMCCrash_140516_3.tiff

[Litjan]

Hi Matt,

as soon as you get the console the first time, all bets are off. Consider the code to be "out of sync" and various things are not going to work anymore...

To really help reproduce the crash, we usually solicit certain .txt files - you can read up on that in the included documentation (bug report guide). Otherwise it is near impossible to recreate the cause, there are simply too many factors.

Once you get the console, close it, then bump your mouse on the right edge of the screen and click the "bolt" symbol to reboot the gizmo scripts. Then you can continue your flight. Only caveat: If you started the whole thing in "turn-around" or "cold and dark" then this will be the state after reboot. But you can work around that by clicking the option "ready to fly" before you reboot gizmo.

Good luck, Jan