The mysterious crash with the A320

[EHM-2173 Bastiaan]

I was flying from Stockholm Arlanda to Klagenfurt with an Airbus 320. I minimalized FS and started to work on my homework. Every now and then I looked in case I got an instruction from the ATC or something. But the last time I looked on this flight I saw something really strange. I was lucky enough to witness my aircraft going spinning in a vertical dive in to the sea just south of Stockholm with all kinds of alarms going off and thing...

I used my autopilot heading/altitude and speed and at the moment I was climbing to FL350.

Does anyone have a explanation for this mysterious crash south of Stockholm. It was my last flight before my rank allows me to fly the A380's and 747's so this is kind of annoying...

[EHM-1612 Paolo]

That's scary :|   The only thing I can think of is wind changes, it used to happen to me when I fly online and wind speed and direction rapidily change...I corrected it with FSUIPC, but I am not sure if your crash is a result of winds...  :[

[EHM-1651 Christian]

It can be the sudden change in wind speed and direction that FS makes between the different flightlevels, which can cause either an overspeed or in your case most likely a stall that results in a spin.

It can also be a stall caused by setting a to high rate of climb causing the Autopilot to raise the angle of atttack*(AOA) to such levels that you loose all to much speed, in a real life A320 this will be impossible due to the Fly By Wire system and FADEC(Full authority digital engine control)  system. If this happens the Alpha-floor system will engage and the engine will be set to max power (TO/GA setting on Airbus) to prevent the aircraft to stall and it will also reduce the AOA to a normal level.

[EHM-2173 Bastiaan]

I think the last explanation about the stall thing comes close to the truth. After al, the stall alarm was going..together with the overspeed alarm what makes it kind of odd..

[EHM-1001 Robert]

I had "something similar" on my last route to Chicago onboard the PMDG-747. As I was approaching the Canadian coasts, because of scenery changes, the Flight Level changed a lot and quite frequently. Then also the wind changed from minute to minute which (I believe) caused to somehow kill the IAS hold system...the "VNAV SPD" sign disappeared from the PFD.

I was watching TV next to the PC... the plane was in VNAV mode with A/T ON since hours... and suddenly it turned off and could not hold the speed, which caused a STALL situation. I realized it only from the sound effect came from the headphones resting on my desk.

I fought with the Autopilot, while after some 3 minutes with scaring passengers behind, I could somehow arm again the Autothrottle, and I could continue the flight.

Although it was not the A320, but I am sure wind changes + scenery level changes caused to kick off the Autothrottle, and if I was not cautious enough, it would fallen down like yours mate.

[EHM-1465 Dominic]

Yep,

I think it's likely that if you set the autopilot to climb to cruise altitude and don't keep reducing the vertical speed as you climb, your airspeed will decrease until the plane stalls, more so when the aircraft is heavier...

This is the reason for step climbs to reach cruise alt as your weight decreases...

[EHM-1838 Andrew]

Hello
May i suggest you leave your homework until you have safely reached your cruising altitude.
It definitely sounds like a stall,which accounts for the stall warning sound plus the overspeed warning sound(as you plummet earthwoods.
cheers Andy

[EHM-0654 Murray]

Ah... this would be the fleet A320 (I think you said...)

One cause of this problem will be the lack of an FMC system... If you had any sort of flight management computer driving the A/P, it'd handle the reduction in climb rate as you progress to cruise in order to maintain airspeed (like Project Magenta does for me when I'm flying any of the fleet Boeings...) I do know that the newer 737's (the NGs) can climb straight to cruise without stepping as long as the FMC does all the work, maintaining climb airspeed and adjusting the V/S as required, and I'd be very surprised if the A320 can't do something similar.

As it is, have a see if you can find a flight envelope profile for the A320; that'll tell you the various V/S's through the climb to keep you close to your MCP speed.

And sorry for all the Boeing terms in this post, I don't know 'buses

[EHM-1507 Manuel]

Sometimes I made similar experiences while flying with "real weather" option activated in  FS9.
It helped to deactivate and activate it again as soon as you have a stable climb again.

[EHM-1651 Christian]

Originally posted by EHM-2173 Bastiaan
I think the last explanation about the stall thing comes close to the truth. After al, the stall alarm was going..together with the overspeed alarm what makes it kind of odd..

The when the stall becomes a deep stall which it often do when getting a to high AOA, causes you to get in a spin causing the speed to get really high.

As far as I know the A320 is capable to go straight into optimum cruise level from a MTOW take-off, ofcourse the last part of the climb is really slow.

[EHM-1749 Hector]

Hi,
maybe this could explain what happens in these situations:
http://www.pprune.org/forums/archive/index.php/t-218633.html
Hector

[EHM-2173 Bastiaan]

I think I'm going to report the crash soon. I think I'll go with Robert that is a mailfunction of the IAS hold system due to a sudden change of wind or perhaps even turbulence. The problem occured before but not on such a massive scale, when my airplane gets kicked so my speed rapidly increases or decreases.

I think it hasn't anything to do with the change of pressure, my experience tells me that those problems only occure above FL340. When te plane started to behave strange it was not likely that it was high enough that a VS of 1200-1500 causes such immens problems. In my 120 hour pilot carreer I never experienced such a thing.

[EHM-1883 Matt]

I had exactly the same over Singapore once during an event...in an A380.

[EHM-2198 Didimo]

I experienced that problem several time with an A320 from iFDG if left in autopilot it tended to suddenly (at random) go unstable and initiate a horrible dive of nearly 10,000'

With a previous model (also iFDG) I also noticed the a/c going in sinousoidal waves up and down several hundred feet when left in A/P to hold altitude.

Later on I saw on Air Crash Investigation that these are called "Phugoid Cycles" I am not sure if I spelled it correctly but it sounds like "Fu-gooid"