Icing encounter - your thoughts

iamtheari said:
Yikes. This thread saves me about $20,000 (Aspen and installation). If I can find a few more threads like this, I’ll be able to afford a certified FIKI plane of my very own.

The pitot tube should be capable of injuring anyone who grabs it. 97F sitting still in the hangar would melt ice off eventually, but it is probably not going to keep up with ice accumulations at -14C (~0F) moving through the air.

The appropriate response to icing in cruise is to escape the icing conditions without delay. You should listen to the advice here about that. Icing forecasts are just forecasts. You can fly when there is 50% chance of icing, but when actual icing happens you need to get out. Your logic is a lot like walking around all day in a rainstorm without an umbrella and claiming you are actually dry because there was only a 50% chance of rain.

Frankly, once you start to pick up airframe ice, you are flying in known icing conditions. Continuing into those conditions without even trying to get out of them is intentional flight into known icing. If you survive the incident that doing this causes, you may want to have a better response to the investigators than saying that the chances of icing were less than 50%.

Your response to the advice in this thread is also a good example of a couple of hazardous attitudes that the FAA even tests on. Anti-authority, invulnerability, and macho all apply. The reason to test on these is because they have already killed enough people, especially people whose day jobs either reward or tolerate these attitudes.

Your pitot heat is broken. But so is your ADM. The latter is the deadlier and more immediate of your problems. Nobody is telling you this because they think they’re better than you, which is how you seem to take it. They’re telling you this because they don’t want you to kill yourself or others, as you seem intent on doing.

Edit: I know that you will likely disagree with me and everyone else who thinks you’re not flying safely. If so, please call our bluff and file a NASA report to call attention to the serious risk that the Aspen failure mode you observed poses.
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Just me, and I could be wrong . .but you oughta write your response, then let it sit for an hour, go back and read it. Before posting. And perhaps read the OP's posts with greater attention. The FAA reference seems to me to be particularly off-point, and nothing in any of the OP's post are a "good example of hazardous attitudes the FAA test for".
 
hindsight2020 said:
I'm frankly surprised people willing to sink 15AMUs installed on these consumer grade toys are surprised by the consumer grade nature of said toys. It's not like the airspeed dependency of these "differential equation solved" attitude depictions is a state secret. The problem is that such criticism always gets cut at as socioeconomic envy. Hey man, no skin off my back; I'm not the one out 20 AMUs while getting to the same destination as the one 20Gs lighter in the wallet with two red Xs in IMC. The class envy accusations I don't have much time for though. Don't want to listen to objective criticism of these GA computer toys? Eat cake then. How's that for a class envy retort....

For the uninitiated. Attitude depictions on these all-in-one tinker toys are based on computer code that solves for the pitch and roll values, based on acceleration information from consumer grade MEMS accelerometers aligned in certain pre-known orientations relative to the box as-installed. Where they proceed to cheap out is in establishing the gravity vector, which is needed to "align" the solution against what can kill you. Toys like the early versions of the RCA 2600 didn't use pitot or GPS inputs at all, making it all MEMS based math, and the precession during acceleration made my mechanical AI look like Apollo Lunar Module docking in quality. Instead, they get around that problem by using airspeed, or worse, GPS speed, to attain that fourth and "caging" variable. Problem is that now No speed means no gonk, means no fancy display, means a red-X four fingers shy of a high-five for you when the chips are down. Oops. Guess ripping out that brass pneumatic AI wasn't such a hot idea after all.

For those who don't fly behind toys, the electronic depictions of attitude are based on no-kidding ring laser gyros that provide direct angle rate information in all three axis by measuring frequency interference of two counter-propagating laser signals (Sagnac effect). Which means, for those keeping track, no airspeed data is needed to provide direct attitude solution. Furthermore, GPS info is used to only update the nav position of the ship, aiding the accelerometers portion of the INS to keep nav position integrity. Not that it needs much after initial alignment, especially in short duration flights. Though airspeed information is embedded into the ADC on most of these INS solutions, loss of airspeed data means Rick-all to the attitude depiction. This is what airliners and birds of killing alike fly behind, and not your Toys-R-Us accelerometer-based Aspen/G5/Dynon.

Even mechanical brass has vanes that inherently point at the gravity vector in order to divert pneumatics and re-cage the presentation card in front of the gyro. Aspen doesn't even have the electronic version of that, which is what it would otherwise need in order to not necessitate airspeed to solve the equations for roll and pitch without a crutch.

So to reiterate. When you buy a garmin/aspen box, you're not buying a RLG. Y'all tracking now? You're buying cosmetics, like your wife does out the door of the CVS, and as such you should consider the manner and severity of conditions in which you launch without a robust attitude information backup. I personally would prefer a brass gyro for a backup, but Needle-ball-airspeed is legal too I suppose. Though the latter is ill advised for the weekend warrior imo, if the stats that led to AC 91-75 are to be taken at face value.

But yeah, class envy. Alright then, you do you boo.
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I think most of these "toys" would need a faluire of both GPS signal and Air data to fail the attitude indicator. The G5 doesn't even mention in the manual to troubleshoot airspeed for a failed attitude.

I'm curious as to how these PFD / MFDs know that a pitot tube is blocked vs a normal 0 airspeed indication???
 
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Sundancer said:
Just me, and I could be wrong . .but you oughta write your response, then let it sit for an hour, go back and read it. Before posting. And perhaps read the OP's posts with greater attention. The FAA reference seems to me to be particularly off-point, and nothing in any of the OP's post are a "good example of hazardous attitudes the FAA test for".
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POA rules prohibit considering the possibility of having misinterpreted other posts. If I was off-base, then I apologize to any whose constitution allows them to be offended by my post. But what I saw here is that the OP flew into likely icing, actually picked up icing, and when he got called out here for that part of his flight his response came across to me and, evidently, others as arrogantly hanging his hat on the chances of icing only having been 50% and anyhow he has flown in icing plenty of other times. Roll the dice until you get snake-eyes if you want, but being lucky in the past doesn’t have any bearing on whether you’ll be lucky in the present.
 
iamtheari said:
POA rules prohibit considering the possibility of having misinterpreted other posts. If I was off-base, then I apologize to any whose constitution allows them to be offended by my post. But what I saw here is that the OP flew into likely icing, actually picked up icing, and when he got called out here for that part of his flight his response came across to me and, evidently, others as arrogantly hanging his hat on the chances of icing only having been 50% and anyhow he has flown in icing plenty of other times. Roll the dice until you get snake-eyes if you want, but being lucky in the past doesn’t have any bearing on whether you’ll be lucky in the present.
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Oh, I wasn't offended; I didn't agree with your evaluation, which to my mind was far enough off the mark to warrant comment.
 
Velocity173 said:
Well, what kind of aircraft do you fly that would produce a burn during a quick preflight check? Plenty of aircraft have the procedure that FT suggested.
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It’s okay to miss a point. With time perhaps it will be learned. Perhaps not,
 
hindsight2020 said:
If true, it appears you have one backup to the airspeed crutch, otherwise it's the same MEMS based approach to attitude. I've seen what happens to GPS derived speed at high angles of bank in the Dynon D1 series (portable, GPS only input). Middle finger.

So. Probabilities of having both pitot (icing or otherwise) failure and GPS outage in level flight in the same flight are pretty low, but in banking flight it could bite you depending on the GPS antenna installation position. Caveat emptor. I'd still keep my brass, but that's just me.
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I hear you with regards to all eggs in one basket. I personally like the display and functionality of the G5 (would love the G500 TXi but too rich for me). I personally love the idea of as many independent redundant ("brass") systems I can have. I didn't get rid of anything to get my cheap glass. I still have my vacuum AI, ASI, VSI, HSI, ALT and even a real old school T&B. I learned needle/ball/airspeed and while I'd prefer to not do it in IMC for funsies, it's all still there if my G5 goes dark and my vacuum pumps go TU. Having a dual vacuum pump failure would be a very low risk, more likely the AI would break and if that happens I have the G5 to help me.
 
hindsight2020 said:
I'm frankly surprised people willing to sink 15AMUs installed on these consumer grade toys are surprised by the consumer grade nature of said toys. It's not like the airspeed dependency of these "differential equation solved" attitude depictions is a state secret. The problem is that such criticism always gets cut at as socioeconomic envy. Hey man, no skin off my back; I'm not the one out 20 AMUs while getting to the same destination as the one 20Gs lighter in the wallet with two red Xs in IMC. The class envy accusations I don't have much time for though. Don't want to listen to objective criticism of these GA computer toys? Eat cake then. How's that for a class envy retort....

For the uninitiated. Attitude depictions on these all-in-one tinker toys are based on computer code that solves for the pitch and roll values, based on acceleration information from consumer grade MEMS accelerometers aligned in certain pre-known orientations relative to the box as-installed. Where they proceed to cheap out is in establishing the gravity vector, which is needed to "align" the solution against what can kill you. Toys like the early versions of the RCA 2600 didn't use pitot or GPS inputs at all, making it all MEMS based math, and the precession during acceleration made my mechanical AI look like Apollo Lunar Module docking in quality. Instead, they get around that problem by using airspeed, or worse, GPS speed, to attain that fourth and "caging" variable. Problem is that now No speed means no gonk, means no fancy display, means a red-X four fingers shy of a high-five for you when the chips are down. Oops. Guess ripping out that brass pneumatic AI wasn't such a hot idea after all.

For those who don't fly behind toys, the electronic depictions of attitude are based on no-kidding ring laser gyros that provide direct angle rate information in all three axis by measuring frequency interference of two counter-propagating laser signals (Sagnac effect). Which means, for those keeping track, no airspeed data is needed to provide direct attitude solution. Furthermore, GPS info is used to only update the nav position of the ship, aiding the accelerometers portion of the INS to keep nav position integrity. Not that it needs much after initial alignment, especially in short duration flights. Though airspeed information is embedded into the ADC on most of these INS solutions, loss of airspeed data means Rick-all to the attitude depiction. This is what airliners and birds of killing alike fly behind, and not your Toys-R-Us accelerometer-based Aspen/G5/Dynon.

Even mechanical brass has vanes that inherently point at the gravity vector in order to divert pneumatics and re-cage the presentation card in front of the gyro. Aspen doesn't even have the electronic version of that, which is what it would otherwise need in order to not necessitate airspeed to solve the equations for roll and pitch without a crutch.

So to reiterate. When you buy a garmin/aspen box, you're not buying a RLG. As such you should consider the manner and severity of conditions in which you launch without a robust attitude information backup. I personally would prefer a brass gyro for a backup, but Needle-ball-airspeed is legal too I suppose. Though the latter is ill advised for the weekend warrior imo, if the stats that led to AC 91-75 are to be taken at face value.
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The surprising thing comes from the fact that the Stratus can give a reasonable attitude solution without any air data. What I would expect is for the Aspen to flag “attitude solution degraded, cross check with other instruments” and give a reasonable solution. rather than just shutting down the attitude display altogether. Pitot ice is way too high-probability to accept loss of attitude display as a consequence.
 
iamtheari said:
What I would expect is for the Aspen to flag “attitude solution degraded, cross check with other instruments” and give a reasonable solution. rather than just shutting down the attitude display altogether.
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That's what Garmin says the G5 does.

iamtheari said:
Pitot ice is way too high-probability to accept loss of attitude display as a consequence.
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Agreed.
 
Do we know for a fact Aspen doesn't have reversion to GPS speed input for its attitude gonculation? Haven't looked at a manual for the product, so genuinely curious.

Also, aren't their installations still limited to retaining a second non-electric AI or electric AI with second electrical system? If so, that would make the consumer grade shenanigans less of an issue (my outright exception to their installed pricing notwithstanding). Again, honest question since I'm not familiar with their STC.
 
hindsight2020 said:
Do we know for a fact Aspen doesn't have reversion to GPS speed input for its attitude gonculation? Haven't looked at a manual for the product, so genuinely curious.

Also, aren't their installations still limited to retaining a second non-electric AI or electric AI with second electrical system? If so, that would make the consumer grade shenanigans less of an issue (my outright exception to their installed pricing notwithstanding). Again, honest question since I'm not familiar with their STC.
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For a single Aspen installation a backup attitude indicator is required just like any other PFD.
 
Clark1961 said:
For a single Aspen installation a backup attitude indicator is required just like any other PFD.
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Is a backup required for a triple Aspen installation? It apparently should be.
 
iamtheari said:
Is a backup required for a triple Aspen installation? It apparently should be.
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The only relevant instal is the double Aspen installation with a PFD + MFD/PFD which will have two AH sensors. The third Aspen is always a “dummy” display. No backup AI is required if an additional battery is installed and perhaps other requirements met. I don’t know the full details just heard a few mutterings from an avionics guy about a difficult installation and an OCD owner. Basically the avionics guy said he wouldn’t even try to do the installation without a backup AI. This stuff is certified guys so even though you may not like the superficial details it isn’t designed and spec’d to automatically kill you if something fails.

Edit to add: be smart about the installation of any PFD guys. I kept all the steam gauges except the VSI when I had the Aspen installed. I also had a wet vacuum pump installed. A lot of things have to go bad before instrument failure is a major problem in the ‘kota. It also drives CFIIs mad because they can’t realistically fail everything...
 
Clark1961 said:
That would have been something along the lines of: the checklist from the Beech suggests...

You obviously failed to do that and had to respond in denigrating fashion to constructive criticism. Tsk, tsk.
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You assume too much. Actually it’s from a Cessna checklist....
 
blueskyMD said:
Name calling om internet is unfortunate . Let me assure you that the message does goes across without name calling. But POA is not an exception its all over the net . It shows how these people were treated growing up.
I have 1700 + hours, all in GA aircrafts. But I still consider my next hour to be the most important. The forecast always calls for icing condition whenever there is any cloud in the sky with temps in freezing range. Not to fly with any icing forecast is always defendable. I am not oblivious of GA risks. Reading NTSB accident reports is my favorite pass time. Nothing in the life is risk free. I personally believe in taking appropriate risk with plenty of caution. I knew that there is out if situation gets bad. As I said the conditions were broken ceiling with high OC. I never lingered around in icing. I asked for vectors in clear air and I quickly got diverted and started the decent to clear air and within very short time I was in clear with no more ice accumulation.
And that's all I have to say about this
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You still haven’t answered the question: are you doing this stuff in an airplane that has some de-ice capability other than just pitot heat?
 
I don't think the OP ADM is terrible. The planning was legit. He had clear air in cruise and melting altitudes below the whole way. He clipped a couple cloud tops and got more icing than forecasted. No biggie. The only thing I would have done differently was request the descent as soon as I identified the trace airframe ice, instead of just accepting it and have the pitot heat failure/underperformance force my hand into the decision that by reg should have occurred immediately upon ice ID.

The OP learned a great lesson when the Aspen gave him the finger, a great thing to learn about the system he trusts his life with, and a relatively benign lesson in how quickly something vanilla like a little trace icing can compound into complications that can ruin your day when combined with other aircraft system nuances like a weaksauce pitot heat for instance. Honestly as far as lessons for free goes, this one is a good one. The OP will be more vigilant of ice encounters in his airplane, address the pitot element issue/electrical, and be more springloaded in the future to treat inadvertent ice, even trace, with the expediency it requires in any non-FIKI spam can.
 
Sounds like you got beat up here pretty well. If you are still following, within this thread is plenty of sage advice. There is no icing that a non-FIKI aircraft is OK in. That is for a lot of reasons. The POH doesn't tell you what ice does to Vspeeds, the induction system, stall system, flap positions. Certification didn't explore whether the airframe is susceptible to tail stall, or the failure points of that aircraft in ice. You also did not receive airframe specific training on icing generated from the engineers and test pilots.

Perhaps, most important to the above discussion. All the forecasts in the world cannot prepare you for what you might find in the clouds below freezing. Forecasts are just forecasts, and often wrong in both directions. Also keep in mind that trace or light icing for one airframe may be moderate or severe for another. I would just say, don't mess with ice in a non-FIKI aircraft. You will never know how close to the edge you are, since in essence you are a test pilot. Fly safe.
 
I am still baffled. Why design an attitude indicator that will totally fail because of a pitot-static problem? That seems so backwards, the two should be independent. A failure of one system should not cause failures of others. I could see the Aspen x-ing out the airspeed indication, but why make the attitude indication use that data? If I have a pitot-static failure, I want an attitude indicator. If I have an attitude indicator failure, I want my pitot-static stuff. Makes no sense.
 
midwestpa24 said:
I am still baffled. Why design an attitude indicator that will totally fail because of a pitot-static problem? That seems so backwards, the two should be independent. A failure of one system should not cause failures of others. I could see the Aspen x-ing out the airspeed indication, but why make the attitude indication use that data? If I have a pitot-static failure, I want an attitude indicator. If I have an attitude indicator failure, I want my pitot-static stuff. Makes no sense.
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These EFIS displays usually require either an air data (airspeed) or a GPS ground speed. The unit uses an algorithm from either of the two to compute a correct attitude. My Blue Mountain requires a GPS signal for the attitude. As a matter of fact, it just failed the other day when I lost GPS signal. The Garmin 500H I fly for work, requires one or the other. My G5, well, I haven't quite figure out yet but I imagine it requires one or the other.

My question still remains, how does it know to put a red X for 0 airspeed as an incorrect indication???
 
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Velocity173 said:
These EFIS displays usually require either an air data (airspeed) or a GPS ground speed. The unit uses an algorithm from either of the two to compute a correct attitude. My Blue Mountain requires a GPS signal for the attitude. As a matter of fact, it just failed the other day when I lost GPS signal. The Garmin 500H I fly for work, requires one or the other. My G5, well, I haven't quite figure out yet but I image it requires one or the other.

My question still remains, how does it know to put a red X for 0 airspeed as an incorrect indication???
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The Aspen has a backup GPS. I suspect it uses GPS speed to determine that airspeed is bad. Why it doesn’t fail over to GPS speed is something I have no clue about.
 
Clark1961 said:
The Aspen has a backup GPS. I suspect it uses GPS speed to determine that airspeed is bad. Why it doesn’t fail over to GPS speed is something I have no clue about.
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And since the OP didn't mention losing a GPS signal, no reason why the attitude should have been red X'd. If that's how an Aspen works, I don't want one.
 
Velocity173 said:
And since the OP didn't mention losing a GPS signal, no reason why the attitude should have been red X'd. If that's how an Aspen works, I don't want one.
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There’s a backup AI so I’m not too concerned. I did go with a wet pump since the backup AI also provides autopilot input.
 
Velocity173 said:
And since the OP didn't mention losing a GPS signal, no reason why the attitude should have been red X'd. If that's how an Aspen works, I don't want one.
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I agree. Did you watch that video of the Atlantic crossing posted above? You can see the ASI go to zero and the Aspens both failed completely. I would say there is almost a zero chance that at the same second the pitot got blocked the GPS's also lost signal. That is an eye opening failure. For those of us that will always choose to keep a vacuum AI it wouldn't be too catastrophic other than attention diverting while IMC but there are people installing these dual units and removing their traditional AI's...that is a scary scenario.
 
Clark1961 said:
There’s a backup AI so I’m not too concerned. I did go with a wet pump since the backup AI also provides autopilot input.
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Well if you have a backup that's non GPS/air data then it's no big deal. I've got a vacuum backup to my crappy Blue Mountain so I'm not too worried. Still, I would think for a certified display like the Aspen, it wouldn't require both inputs in order to display attitude.
 
midwestpa24 said:
I am still baffled. Why design an attitude indicator that will totally fail because of a pitot-static problem? That seems so backwards, the two should be independent. A failure of one system should not cause failures of others. I could see the Aspen x-ing out the airspeed indication, but why make the attitude indication use that data? If I have a pitot-static failure, I want an attitude indicator. If I have an attitude indicator failure, I want my pitot-static stuff. Makes no sense.
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Occam's Razor. The box was certified with the provision the mechanical AI to remain in place as part of the *STC (*single box installation variant), therefore Aspen can afford to be ham-handed about their fail modes. That's it man, no conspiracy. I hear that though, for what they're charging for that box, hoo boy. But I've already said my peace about that in a previous post so I digress.

The good news is that it's just software, they could just as easily flash a software revision where they merely flag it as opposed to Xing it out. Of course, they could also write the code to take in the GPS speed as reversion mode, and voila, backup to the pitot.

What it does show is that Aspen is comfortable coasting downhill and cashing checks. They got their little cow and they're milking it. Their monkey their circus, and as long as folk line up to pay 15K installed for their IFR software boxes, then there's not really a problem now is there?

Gotta vote with your wallet.
 
I will admit to having ZERO glass panel experience. I knew EFIS did not use typical gyros as such for information. I guess I though there was some whiz-bang solid state accelerometer or something that provided the attitude indications. I would have never guessed it was using pitot/static information, or that a single point failure of the pitot/static system would affect attitude indications. Learn something new everyday.
 
midwestpa24 said:
I will admit to having ZERO glass panel experience. I knew EFIS did not use typical gyros as such for information. I guess I though there was some whiz-bang solid state accelerometer or something that provided the attitude indications. I would have never guessed it was using pitot/static information, or that a single point failure of the pitot/static system would affect attitude indications. Learn something new everyday.
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You're conflating terms here. EFIS has nothing to do with attitude. I know it was a TL;DR post, but I encourage you to re-read post #38. I explained the differences between direct attitude measurement instrumentation (mechanical gyro, RLG) and accelerometer-based "back-solving" attitude instrumentation (most consumer grade stuff). The methodologies of arriving at attitude information are fundamentally different between the two, and not at all an inconsequential difference.
 
yes, and hopefully the fanbois on here will finally realize the pitfalls of bringing a knife to a gunfight just because you spent gun money for it.
 
hindsight2020 said:
yes, and hopefully the fanbois on here will finally realize the pitfalls of bringing a knife to a gunfight just because you spent gun money for it.
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Not sure why you're hating on these EFIS displays but the odds of my G5 or our G500H losing both air data and GPS simultaneously is slim. If it does, that's what a mechanical backup is for.

We might be spending "gun money" but what's the alternative? Yes, a RLG or the FOGS I flew in the Army is much more advanced but I'm not going buy something that costs more than my plane either.
 
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Velocity173 said:
Not sure why you're hating on these EFIS displays but the odds of my G5 or our G500H losing both air data and GPS simultaneously is slim. If it does, that's what a mechanical backup is for.

We might be spending "gun money" but what's the alternative? Yes, a RLG or the FOGS I flew in the Army is much more advanced but I'm not going buy something that costs more than my plane either.
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dont misunderstand, im not hating on the merits of ga glass, im just throwing spears back at the cohort that came at me with the socioeconomic ad hominem just because i dared highlight the limitations that system has over traditional electric/vacuum six pack.

this also happens to be a spillover argument from another forum, so forgive me for the lack of context. this has nothing to do with aspen or g5, its more about a sweater wearing richard or two. so we're cool brother. :D
 
Just spray you’re leading edges and prop with “Easy Off” oven cleaner .... ice just flies off (this is of course a joke to apply a little levity to this thread)
 
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