Hi all,

 

first I have to say I was away of virtual flying for month, I think and in this time I neither edited something related to FSX nor opened it at all. However when I now try to fly with the NGX i get random faillures, eventhough I have set it to off in the FMC.

Of two times of flying this happened two times. I will continue testing, I know two times sounds like nothing.

Here is what happened:

Number 1:

I was sitting in the cockpit of the 737-800 in EDDT in the cold and dark state. I done the standard procedure wich includes to set the IRS into the "nav" position. After 10 mins of doing all the other stuff I get the message "Enter IRS positon" in the FMC. Until now everything seemed normal. So I entered the IRS position by copy and paste it from the GPS position from the next page. First it looked like nothing happened, because the captains displays looked just as before entering the IRS positon (also after waiting a few minutes). I remeber I had this issue a while ago but the solution for this was that I have gone to the toilet and as I came back the displays showed what they are supposed to do. But this time there was something different: The FO displays worked properly- I THOUGHT. After taking a closer look to the ND, I recognized the tcas isn't working( tcas fail), but on the captains side there was just standing "TCAS off". I made a TCAS test and it failed. After a long start up sequence and one month free of flying I thought to myself I try it as a FO. TCAS is not soooooo important on the computer. After that I simply continued as if nothing happened. Taxi, Takeoff, Gear up, Autothrust - next problem. No autothrust at all. Neither VNAV nor SPD. LNAV was also not working. Again I thought I still got HDG and I can do the thrust by myself. Autopilot on - not working. It seemed like the hole mcp was just there to show some numbers of my choice with some nice knobs, too, but wasn't connnected to the plane. I aborted here. Unfortunatly I didn't took pics.

 

Number 2:

One day later, again the -800, this time in LPFR, all IRS/TCAS errors were solved.Everything went normal - until takeoff. From cold and dark to takeoff I have done some, I think irrelevant, things different: IRS alignment time was instant instead of realistic and I planned to do some traffic patterns, so no route I just selected a runway for departure and one for arrival which was the same one. Already during taxi I thought: " Wow braking is smooth, i remember it was hard and felt like the passengers are bouncing with there head on the seat in front." Now the takeoff: I was planning to do a rolling takeoff, when I recognized some takeoff items weren't set yet. New decision: Line up and wait or position and hold, as you prefer. As i centered myself on the runway I recognized the brakes aren't working. Neither manual nor parking brake. Doesn't matter I thought, so takeoff, gear up autothrust - not working. But after a few seconds it engaged, evrything fine now but then I hear the firebell and the fire warning is shining red. I took a look through the cockpit but neither the APU nor the engines were on fire. So I were cutting off the bell, took a look outside and nothing. No smoke, no limitations to the flight behaviour, nothing. Unfortunatly I didn't tested the autopilot.

Minutes later touchdown, autobrakes 1, reverse thrust, speed brakes. 80 knots, going into idle and then the runway edge reminded me to the brake failure.

 

That's it.

 

Help is much appreciated.

 

 

Greatings from Germany :)

Sounds like you overheated your brakes causing them to fail which is why they didnt work and caused a wheel well fire.

Pull out the QRH and follow the proper checklist(s). Or you can turn off the service failures.

They are not random failures.

About the IRS probably you did something wrong.

If autopilot and other functions were not working, and one side working and one not, you probably did something that caused it.

What? There are many causes, you probably moved the plane at first alignment, you have probably not waited for ALIGN to go off before re-starting IRS.

The TCAS was failed on FO side wich had the IRS malfunction (one TCAS, if fails on one side only the problem is in other functions, not the tcas), LNAV and other complex functions are IRS dependent so, if one of them is in ATT or not aligned correctly you will loose functions.

737 has no autothrust, it is called autothrottle (the difference is not only the name compared with the modern autothrust planes)

About brakes is the same, is not a random failure but a user usage failure that occurs if brakes are abused.

Learn to use the plane and the "failures" will gone.

Two IRS'es are separate systems and their aligning time can be different. Didn't you get "IRS motion" message after starting moving. Alos you had to check annunciations on IRS panel.

Other problems on first point of your question are related to not aligned IRS.

I think you will be able to turn on CMD B and put your XPNDR switch into 2 position on transponder panel so it will take information from F/O's IRS.

It's possible that the brakes overheated but before taxi I was standing at the parking position before so when have I overheated the breaks?

Learn to use the plane and the "failures" will gone.

Are you serious? I'm flying the plane since it is out so I think I know how to use the plane. Is there any reason to be agressive? I don't think so.

Maybe I have done something wrong I will retry it in the same situation.

Alexander, I'm not aggressive , probably I missed to add smileys , it is a problem of written words. :Praying:

However the fact is that with a probability of 90% all your problems are user fault aligning the IRS and same thing for the brakes.

It has nothing to do with programmed (random or not) failures.

Don't worry about my words, I also heat a lot the brakes sometime, and also real pilots do that in few occasions.

Same for IRS, also pilots can make mistakes. We are all humans.

 

If you see that you're doing all correctly and it is not working again, so you're able to replicate, it could be useful to record a little video and post it so we can see where the problem is.

Of course I could have made a mistake but the question is how could the breaks overheat when standing at the gate. I assume that it is very likely that they were overheated but I don't get why?

Probably your brakes overheated during taxi, probably when starting to turn at high speed you hit the brakes.

Or, if you have an axis assigned you could have few brakes applied also if you're not pushing the pedals. This can be confirmed by watching the brake temperature during taxi.

The fire bell is due to the brake temperature that heats the wheel well (check on the fire panel the red WHEEL WELL light). In this condition you may risk an hydraulic leakage, wheel explosion and so on, so, gear down until brakes are cool.

However, when failed, you will still don't have brakes and need to load again the flight.

 

Just as a precaution, check brake temp after panel loading. ;)

I'll keep that in my mind for the next time :)

Just made a flight and, as expected, everything went fine.

Tanks for your support.