Airspeed suddenly goes to zero inflight

[gavi25 2]

Good evening,

I have experienced problems over the years with the wings flattening and airspeed going to zero inflight on many aircraft. As has been suggested before, its to do with the pitot heat and anti-ice being on or off, and many people have had the same problem.

This I have tried and made no difference, the problem still kept happening. So I thought, I would look up the an explanation of every single section of the aircraft cfg to see if there was something I have missed. I had a found a full explanation of aircraft configuration files by Microsoft which is very helpfuil, and so did a search on that webpage using the word 'deice'. Low and behold, a section on the webpage came up that I had never seen actually in any aircraft cfg file. Here it is:

[deice_system]

structural_deice_type=1

This section defines the deice system of the aircraft.
0 = None
1 = Heated Leading Edge
2 = Bleed Air Boots
3 = Eng Pump Boots.

Examples

Airbus A321( structural_deice_type=1 )
Aircreation582SL( structural_deice_type=0 )
Beech Baron 58( structural_deice_type=3 )
Beech King Air 350( structural_deice_type=2 )

I've now added this to all my aircraft and so far, have not had a single problem.

Hope this is of help to people if you experience the same as me for many years.

Kind regards

Gavin

 

[bowingic 7]

Thanks for the heads up on this. I have experienced this on the LevelD767 for FS9. Usually it would go to zero and then a short time (30secs or so) later return to normal. Interested to know if you had it return to normal or did it just stay zero? I had always thought it was just a LevelD bug.

Cheers

Ian

[Skywatcher 133]

I hope this works. Yes, always been a problem as far back as I can remember. Will certainly try it out. Thanks for what could be a great find!

[John Hinson 22]

If you used have an add-on weather programme it may have added icing issues in the FS9.CFG file, and possibly even left them there after de-installation.

I had exactly that problem once and although I couldn't identify exactly what was wrong in that file, deleting it and automatically re-creating it resolved the problem.

Of course, doing that will neutralise a lot of your other settings so keep a backup so you can copy sections across.

John

[Skywatcher 133]

I know it's an old-ish thread but I have now had time to fully evaluate this.

It hasn't worked. I've come to the conclusion icing simply does not function correctly in the sim. I have applied the only 100% fix, I've removed icing conditions from my FS9.

[C16thFoxe 0]

See: icev10.zip by Charles (Dutch) Owen. Read the detailed icing document to see how a Missed Opportunity [is] Partly Redeemed.

[Skywatcher 133]

1 hour ago, C16thFoxe said:

See: icev10.zip by Charles (Dutch) Owen. Read the detailed icing document to see how a Missed Opportunity [is] Partly Redeemed.

Ok, will check it out, thanks.

[DDP65 0]

Hi,

This is a problem that I encounter too.

It mostly seems to happen on climbs and/or descents, never when cruising at +FL300..., with freeware and payware aircraft. And after some 10-20 sec. it's gone again. It's only problem is that it makes the A/T think airspeed is 0kts so throttle goes to full power.

I use AS6.5 or ASE, with historical WX files. If I restart my flight with the same WX file, I'll encounter this at the same location.

Going into the FS9 settings and selecting TAS instead of IAS resolves the problem, but the realism is gone.

I use FSCaptain, made by Charles Owen (its Icing gauge icev10.zip function is incorporated into the FSC weather hazards), On it's signals testing page it indicates that the Pitot Heat signal is OK. But this continues to occur.

A possible solution I have yet to try out is this setting from MS:

https://docs.microsoft.com/en-us/previous-versions/microsoft-esp/cc526949(v=msdn.10)#pitot_static

 

Regards,

DDP.

 

 

[BlueStar 323]

Sounds like the pitot heat is off. Push "H".

Bill 

[Dave Morgan 68]

On 3/26/2019 at 9:24 PM, C16thFoxe said:

See: icev10.zip by Charles (Dutch) Owen. Read the detailed icing document to see how a Missed Opportunity [is] Partly Redeemed.

 

Just downloaded on the strength of the information given in the included icing.txt document. I had no idea proper icing could be simulated in FS9: all I've ever seen is the a/c weight increasing with little effect on aerodynamics. I may have a play with this tonight -- it will make winter flying more interesting!

 

As it works in FSX, does anyone know if it also works in my other sim, P3D?

 

D

[John Hinson 22]

I don't think that document covers everyting, fascinating though it is.

One observation I have made is that in FS9 aircraft only seem to respond to ice if there is a switch to control that particular condition. So it seems a simple panel without, say, a wing-deice switch will not experience wing icing issues, same for prop de-ice etc.

I am not sure whether the Pitot heat switch behaves the same way but BlueStar may be assured that this curious temporary behaviour definitely occurs with Pitot heat turned on. My experiences are identical to DDP's, on climb or (most commonly) on descent and a common factor certainly is that I use ASE. It might not be ASE itself of course, but perhaps a conflict with FSUIPC's weather settings or other add-ons.

It could even be that I would never notice the needle drop to zero for a second or so if I wasn't using Flight Deck Companion - I am alerted with calls for flaps and gear from my co-pilot as the speed has theoretically dropped to a level that needs them. This problem could be more widespread but rarely noticed.

John

[Skywatcher 133]

Same here, occurs in same situations and also using ASE.

[BigGiraffe 0]

Good Evening,

I only started to notice this problem in the last couple of months.  To me, it seems as though there is a timer on the "Pitot Heat" function that wasn't there before.  (I have no explanation for it suddenly appearing).  When I lose airspeed indication, I cycle the Pitot Heat switches and the airspeed returns in a few seconds.  I have not tried leaving the switches alone to see if the indication restores itself, so will try to remember to leave things alone next time.

Kurt

[Skywatcher 133]

22 minutes ago, BigGiraffe said:

Good Evening,

I only started to notice this problem in the last couple of months.  To me, it seems as though there is a timer on the "Pitot Heat" function that wasn't there before.  (I have no explanation for it suddenly appearing).  When I lose airspeed indication, I cycle the Pitot Heat switches and the airspeed returns in a few seconds.  I have not tried leaving the switches alone to see if the indication restores itself, so will try to remember to leave things alone next time.

Kurt

The Pitot Heat switches seem to have no effect. I've had them on and off at all kinds of various points but any changes made no difference. Are you also using ASE?

[BigGiraffe 0]

Good Evening,

The weather I'm using is FS Global Real Weather.  And, thinking about it, that might be about the time I started to notice the airspeed dropping off as described.  Prior to that, I was using FSRealWX Lite.

Kurt