Jump to content

Sign in to follow this  
Guest vbmartell

Airspeed drops to zero

Recommended Posts

Guest vbmartell

HiMy airspeed drops to zero while on autopilot final approach.This has happened several times.I am wondering if AS is updating on-line at the time?I set options in AS for no updates below 10,000 feet thinking that would solve the problem .... no luck.Regards,Vaughan MArtell

Share this post


Link to post
Share on other sites
Guest hlm65

Hi,maybe is the infamous "icing issue" of FS9.Check ON the "prevent all icing" in AS options and this will probably prevent any "zero airspeed" issue. You'll get less realism, but smoother rides !

Share this post


Link to post
Share on other sites
Guest vbmartell

OK,Thanks for the input. I will give your suggestion a try.I did have pitot heat on.No problems at higher alitiudes.Only happens on approach!Wondering?Vaughan Martell

Share this post


Link to post
Share on other sites
Guest vbmartell

Hi,Yes, pitot heat ONDEice ONflying 737-400Vaughan Martell, Jr.

Share this post


Link to post
Share on other sites
Guest hlm65

It happened to me several times mostly at lower altitudes (with Pitot heat ON) till I disabled all icing in AS2004. It's a FS9 bug. It could also be solved (at least with PMDG 737) switching views from front to left and right, normally it clears itself in less than 5 seconds. But the best solution is the icing disable option checked, 'cause you don't want to take a look around on short finals or just after liftoff whil hoping your airspeed goes again in healthy figures !Best regards.

Share this post


Link to post
Share on other sites
Guest vbmartell

Hi,Thanks again for taking time to get me straight on this. Regards, Vaughan Martell, Jr10nm SE of KDTW (currently experiencing iceing, if you know what I mean?)

Share this post


Link to post
Share on other sites

I've found that if you'd turned on pitot heat on the ground before you are in the air and get the icing, MSFS isn't aware of that. Airspeed will still fall to zero when it determines icing has happened. If you then just cycle the pitot heat off and back on, it sorts itself out.

Share this post


Link to post
Share on other sites
Guest vbmartell

Very interesting.I will try it next time it happens.Thanks for the input.Vaughan MArtell

Share this post


Link to post
Share on other sites

This seems to be the most cogent advice:> This is a common problem in FS with a number of add-ons.>> If you experience severe (level 5) icing in MSFS, it will freeze your pitot tube, resulting in a zero-airspeed excursion, regardless of pitot heat setting. >> In FSUIPC, you should deselect random icing in clouds, restrict max icing to level 3, and select the "allow FSUIPC to interfere with FS own weather" options. That has worked well for me.>> Regards>> Bob Scott> ATP IMEL Gulfstream II-III-IV-V L-300> Washington, DCSince doing this, I see this very seldom, but even then still see it occasionally.Turning "disable all icing" on in AS did not prevent this from happening for me.I have not seen this problem occur with AS not running, but not running AS seems unthinkable. * Orest-~~~~~~~~~Orest SkrypuchUAL1445 DENFOCYFD - Canada

Share this post


Link to post
Share on other sites
Guest vbmartell

Bob,Thanks for the detailed explanation and fixes.Do you know, like in real life, what is done in a situation like this.Do we level off, autopilot off, basic instrument scan, rely on N1/N2indications for basic manual thrust (GPS for basic ground speed), then get out of the icing conditions as soon as possible.Hard order though when it normally happens on final approach.To make the changes you suggested do I need the licensed (purchased) version of FSUIPC?Thanks for all your time and assistance,PPSELVaughan MartellKDTW/KSAN

Share this post


Link to post
Share on other sites

Vaughan,Well, you're welcome.I thought I'd credit Bob, that seemed to be the best suggestion that I have found, and seems to work for me most of the time.Yes, you need the registered version of FSUIPC.I quickly turn off A/T if I have it on, and use the manual throttle guided by the GS. If you don't have it on the panel, then use the Shft-Z display to show it along the top.After about a minute the situation clears, but that can be a hairy minute if you are in the middle of a tricky climb or on final, and the dang A/T throws you off the glide slope.Happened once on the Canarsie climb, I got distracted, over turned and ATC called asking why I was heading back to JFK. * Orest-~~~~~~~~~Orest SkrypuchUAL1445 ORDFOCYFD - Canada

Share this post


Link to post
Share on other sites
Guest vbmartell

Ok,I will get the registered copy of FSUIPC, set it up, and see if I have better luck next time it happens.Actually, I have never crashed because of the airspeed drop but I did not have a procedure ready to execute in case of the problem.Thanks again.Vaughan

Share this post


Link to post
Share on other sites

>Actually, I have never crashed because of the airspeed drop>but I did not have a procedure ready to execute in case of the>problem.That's good because frozen pitot tube doesn't mean wings no longer develop lift. But it all means there is a bug in FS - I never heard of icing so strong that a heated pitot tube could not overcome.Michael J.WinXP-Home SP2,AMD64 3500+,Abit AV8,Radeon X800Pro,36GB Raptor,1GB PC3200,Audigy 2

Share this post


Link to post
Share on other sites
Guest vbmartell

HiThat makes my day knowing that. Thanks for the input.Vaughan Martell

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...