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RV9A Hit Icing At Night

Wow. That is really interesting and scary. It is so tempting to go through a thin layer of clouds or pick a hole to punch through.

I have the same plane and panel this pilot has. I hope he comes on the forum to discuss this further.

Question: If he had an ipad would it have displayed the correct information on Foreflight or Garmin Pilot? I believe my ipad gets its info through the panel so it may have had bad data too.

Another question - would a Sentry send correct data to the ipad? If it does, Im ordering one today.
 
rockwoodrv9 said:
Another question - would a Sentry send correct data to the ipad? If it does, Im ordering one today.
Click to expand...

The Sentry will send data to your iPad but the speed will be GPS speed instead of IAS. BTW, the Sentry Mini does not have reference data, only the larger Sentry does that.
 
Sounds like iced over static ports from his report, alt static would likely have fixed his AS/ALT errors but when things happen that fast it's easy to miss something as simple as that. IFR at night picking up ice.... he's lucky to still be with us.

We lost a 757 way back with taped over static ports, everything goes nuts when the ADC's don't have good info, The bottom line to maintain control when AS/ALT go wonky is pitch and power, forget the rest. Start chasing erroneous AS and you're in trouble.
 
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Wow. A write-up I'll bookmark. I'm down at the other end of the state, finishing my IFR ticket. Same setup, 9A, full glass, dual static (ostensibly to try and prevent single port clogging/icing, no less), and I'm at the other end of the state in Cincinnati. Three times this past week my instructor and I cancelled my final checkride prep hour because conditions were /right at the edge/ of potential icing. Not much gives me real pause, through all the practical risk mitigation I think I've done while building and equipping my bird. This is one of them.
 
Glad he got down ok. Probably pretty nerve wracking.

Remember you have GPS speed and altitude as a backup with pitot/ static failures. This possibly could have saved a couple of night airliner crashes had they crossed checked these after getting nonsensical data from the altimeter and ASI.

Be careful at night, had a friend who flew into a heavy snow shower at night VFR at fairly low altitude over the countryside with almost no ground references. Very lucky to be alive.
 
Very interesting read, glad the pilot made it safely back.
I'm interested to know where are the static ports on a -9-, compared to a -8- ?
Are they more prone to icing ?
Planning on equiping my -8- for IFR, and of course icing is always a major concern.
To remove a "VFR ONLY" restriction here (Canada), one has to have an alternate static source.
Was I told back then, with steam gauges you could break the glass of the vario if suspecting a static blockage ???
I never had a tool on hand to break that glass... :rolleyes:
 
A great read, and eye opening for sure. I do not have my ifr ticket but am working on it. I recently upgraded my panel with IFR capabilities in mind. I debated about installing an alt static port on my panel, now am glad I did (Stein toggle under red cover). I watch a lot of accident videos, glad this event had a good outcome.
 

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Personally I've given this alt static situation thought in the past few weeks. For me, my static line runs right under the side canopy rail deck on my side of the plane. So if truly necessary, I can grab the line and cut it with a pocket knife to get cabin static pressure. Running a new tube afterwards is cheap. :D
 
I’m hitting the jackpot today with helpful tips… even if they currently apply to my Glasair G3x upgrade and not my RV-3. After having recently lost a good friend who was my go to guy for all things aviation, it’s really fantastic to have this site. Well worth the price of admission!

I wasn’t aware of this alternate static toggle switch before this post. I’ll order one right away before Stein sells out! In fact, I might as well order 2 of them because my RV-3 will need one when it gets a panel upgrade!
 
In his own words...

"Taking off was a mistake. I thought that temperatures in the clouds (low 20's) would mitigate liquid water presence. Should have stayed snug in the Hilton."
Click to expand...

People underestimate the icing conditions in the Great Lakes areas downwind of those lakes. Glad he's still here to relay his experience. These are light IFR airplanes at best, fly them that way.
 
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sbalmos said:
Personally I've given this alt static situation thought in the past few weeks. For me, my static line runs right under the side canopy rail deck on my side of the plane. So if truly necessary, I can grab the line and cut it with a pocket knife to get cabin static pressure. Running a new tube afterwards is cheap. :D
Click to expand...

Quite honestly, imho a procedure that requires both hands and involves a sharp knife, at a time when all sorts of instruments are failing and you are under high stress, is probably not a great solution. The Stein ‘switch’ mentioned elsewhere is a good solution. At a minimum, put a T in the line, with a cap on one branch - a cap that can easily be found and unscrewed with one hand.
 
An alternate static source is easy to plumb, and is required for certified aircraft. I put one in all of my aircraft.

I had the EXACT same problem years ago climbing out of Cleveland. I recognized the blocked static ports prior to entering IMC and opened the alternate static port (Bonanza S-35) and everything returned to normal immediately. I recognized that the airspeed was rapidly decaying, but power and pitch attitude were perfectly normal. It was an indication problem caused by a faulty static system.

My guess is that the static ports did not really freeze over. I've not seen icing accumulate on the aft fuselage. My thoughts are that the static lines are routed in such a way that they trap water inside the fuselage. Then the water froze in there. I've written articles about this.

I only continued the flight because we were climbing through a thin layer, and it was clear above. It was also clear at home (Atlanta). When I accepted the clearance I asked for an unrestricted climb to 10K', which was granted. When I got home, I dosconnected the static lines and blew a bunch of water out of them. It had been raining all week in Cleveland and the airplane was parked outside. Then it got cold and froze.

Yes, the comment about the fuel vents is very important. I drill a hole on the back side of my fuel vents to help with that, as the ice usually accumulates on the front side of the vent. In the few times that I have been in icing in the 10, mainly in Alaska, I remind myself to swap the fuel tanks every few minutes while I am working with ATC to get out of the icing. NO sense having to deal with fuel starvation while dealing with ice. ATC is very accomodating when you mention ice. They immediately assign a block altitude, and usually within 1000' feet the ice is shedding.

Vic
 
Consider

sbalmos said:
Personally I've given this alt static situation thought in the past few weeks. For me, my static line runs right under the side canopy rail deck on my side of the plane. So if truly necessary, I can grab the line and cut it with a pocket knife to get cabin static pressure. Running a new tube afterwards is cheap. :D
Click to expand...

Consider two scenarios:

1. Flying into similar conditions, you experience airspeed/altimeter issues. Those instrument are going to be giving you information; WRONG information. You have been taught to believe your instruments. So now your brain is presented a conflict...what to do. Meanwhile, you are attempting to fly the aircraft in IMC. You decide it is a P/S problem. So you reach into your pocket, find your handy swiss army knife that has 15 different gadgets on it, find the blade and open it with one hand, locate the tube running along the canopy, and, with one hand, cut the nylon tube. All while attempting to fly a sensitve aircraft in IMC.

2. Flying into similar conditions, you experience airspeed/altimeter issues. Those instrument are going to be giving you information; WRONG information. You have been taught to believe your instruments. So now your brain is presented a conflict...what to do. Meanwhile, you are attempting to fly the aircraft in IMC. You decide it is a P/S problem. So you reach out to the red guarded switch , and with one finger, switch to ALT air. All while attempting to fly a sensitve aircraft in IMC.


The examples are not to judge but to illustrate what you might potentially be dealing with.

In another section of my life, it was demonstrated, in no uncertain terms, what happens when you have an adrenalin dump...which would likely be the case in these scenarios. Three things will happen with that adrenalin dump:

1. You WILL get tunnel vision.

2. You WILL lose your hearing.

3. You WILL lose you fine motor control.

I know which scenario would have better odds of a successful outcome. At work, we practice unreliable instruments in IMC (in the sim). It is an eye opening experience.

Know what a good pitch/power setting is in your aircraft; if you suspect unreliable instruments, fly that pitch/power.
 
Just asking...
Why the guarded switch ???
If opened by error, either by hitting it or other, I don't see an immediate issue. Maybe a small IAS or Altitude error ??
 
riseric said:
Just asking...
Why the guarded switch ???
If opened by error, either by hitting it or other, I don't see an immediate issue. Maybe a small IAS or Altitude error ??
Click to expand...

You are correct. If you activate it in level flight you will notice an increase in altitude and airspeed. If coupled to an autopilot at the time, it can cause a good pitch change.

So, why leave it guarded? So that it is only purposefully activated, and not inadvertentaly bumped on or left on. When performing an approach to minumums in actual IMC conditions you certainly wouldn't want your altimeter to read 100" high (or even more in some cases).

For this reason, during flight testing you would want to fly at various speeds and determine how much the indicated altitude and airspeed change just in case you need to use it for real someday.

Vic
 
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Even with alt air there are still insturmation errors, small but still. Why not keep it guarded?
 
On my system, I always display GPS altitude. As a generalization, fly the GPS altitude 500' higher than what you would want with baro altitude.

Don't forget that pitch works when pitot static instruments don't work. I once had a mean-hearted CFII cover all the pitot-static instruments (in the Cessna 175) and I successfully flew an ILS, determining minimums by being on the glideslope and by position. On the other hand, it if had been a real situation, I would have flown it all the way down, regardless.

On my airplane, a clogged pitot also means no AOA.
 
IMHO this could have been avoided. From the link, the pilot stated this…..

“ Taking off was a mistake. I thought that temperatures in the clouds (low 20's) would mitigate liquid water presence.”

23F (5C) is dead center of the 0 to -10C structural icing range.

Dean Martin probably said it best. Good judgement comes experience. And experience? Well that comes from poor judgement.
 
Flying real IMC, having the pitch vs power knowledge of your aircraft is a most important attribute.

Indicated airspeed is a nice to have thing... a read of a GPS GS or a quick confirmation by ATC will probably give some clue.
 
Vic, where did you place the holes along the rear vent and what diameter. This is a good flight safety mod I would like to do to my -10
 
Dan 57 said:
Flying real IMC, having the pitch vs power knowledge of your aircraft is a most important attribute.

Indicated airspeed is a nice to have thing... a read of a GPS GS or a quick confirmation by ATC will probably give some clue.
Click to expand...

Yup. These simple facts drummed into pilots heads and added to SOP could have saved a couple of the big pitot/ static failure crashes. Have to first recognize the signs but I was taught that in ground school early on and it stuck with me. Night adds another element, likely slowing recognization of a problem.

The AF447 accident crew certainly never put this all together- known pitch and power will keep you flying.

I always glance at GPS GS on final as a cross check to the ASI. This gets you in the habit if something here was to pack up.
 
Ed_Wischmeyer said:
On my system, I always display GPS altitude. As a generalization, fly the GPS altitude 500' higher than what you would want with baro altitude.

Don't forget that pitch works when pitot static instruments don't work. I once had a mean-hearted CFII cover all the pitot-static instruments (in the Cessna 175) and I successfully flew an ILS, determining minimums by being on the glideslope and by position. On the other hand, it if had been a real situation, I would have flown it all the way down, regardless.

On my airplane, a clogged pitot also means no AOA.
Click to expand...

This does raise a good point. I have my systems set up to show GPS alt and ground speed, as well as a GPS-based AGL readout. the IFR pilots all need to learn to watch these as we fly. They are excellent crosscheck tools for the experience we are discussing. In this story, a 1 second glance at the GPS ground speed reading would have tipped off the pilot that a pneumatic airspeed error was occurring. THis may or may not have been enough to connect the dots on the static problem, but would have significantly reduced the panic level. Bob raises a great point about adrenaline intoxication. If you train yourself to regularly check these items, it is far more likely that you might cross check them in a case like the one highlighted here. In times of panic, those ingrained habits are the most likely to shine through. Trying to think back to the lessons learned in this thread two years later, not so much.

Larry
 
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Words to LIVE BY

MIKE JG said:
In his own words...



People underestimate the icing conditions in the Great Lakes areas downwind of those lakes. Glad he's still here to relay his experience. These are light IFR airplanes at best, fly them that way.
Click to expand...


Just stay on the ground, carb icing is common occurrence in St. Pete/Tampa area this time of year and I learned early to stay on the ground when things were on the edge wx wise...;)
 
vic syracuse said:
You are correct. If you activate it in level flight you will notice an increase in altitude and airspeed. If coupled to an autopilot at the time, it can cause a good pitch change.

So, why leave it guarded? So that it is only purposefully activated, and not inadvertentaly bumped on or left on. When performing an approach to minumums in actual IMC conditions you certainly wouldn't want your altimeter to read 100" high (or even more in some cases).

For this reason, during flight testing you would want to fly at various speeds and determine how much the indicated altitude and airspeed change just in case you need to use it for real someday.

Vic
Click to expand...


Sold !!! Guarded it will be.
Thanks Vic,
 
Video idea

vic syracuse said:
An alternate static source is easy to plumb, and is required for certified aircraft. I put one in all of my aircraft.

I had the EXACT same problem years ago climbing out of Cleveland. I recognized the blocked static ports prior to entering IMC and opened the alternate static port (Bonanza S-35) and everything returned to normal immediately. I recognized that the airspeed was rapidly decaying, but power and pitch attitude were perfectly normal. It was an indication problem caused by a faulty static system.

My guess is that the static ports did not really freeze over. I've not seen icing accumulate on the aft fuselage. My thoughts are that the static lines are routed in such a way that they trap water inside the fuselage. Then the water froze in there. I've written articles about this.

I only continued the flight because we were climbing through a thin layer, and it was clear above. It was also clear at home (Atlanta). When I accepted the clearance I asked for an unrestricted climb to 10K', which was granted. When I got home, I dosconnected the static lines and blew a bunch of water out of them. It had been raining all week in Cleveland and the airplane was parked outside. Then it got cold and froze.

Yes, the comment about the fuel vents is very important. I drill a hole on the back side of my fuel vents to help with that, as the ice usually accumulates on the front side of the vent. In the few times that I have been in icing in the 10, mainly in Alaska, I remind myself to swap the fuel tanks every few minutes while I am working with ATC to get out of the icing. NO sense having to deal with fuel starvation while dealing with ice. ATC is very accomodating when you mention ice. They immediately assign a block altitude, and usually within 1000' feet the ice is shedding.

Vic
Click to expand...

Sounds like a great topic for your next Baseline video.
 
Note that ForeFlight can display Baro Altitude (when connected to an ADS-B In device equipped with a barometric pressure sensor), in addition to GPS Altitude and AGL Altitude.

https://support.foreflight.com/hc/e...-Can-I-view-indicated-altitude-in-ForeFlight-

"The Baro Altitude instrument and the Altitude Tape in the AHRS view can display pressure altitude corrected for local barometric pressure, otherwise known as indicated altitude.

i-22VqZG6-L.png


To display Baro Altitude, ForeFlight must be connected to an ADS-B In device equipped with a barometric pressure sensor, such as a Sentry. (ForeFlight does not use the barometric pressure sensors built into some iOS devices.) It can then use various data types to convert pressure altitude to indicated altitude. These include:

• ADS-B data from an ownship target or nearby traffic.
• Altimeter settings from the nearest METAR report within 100 nm.

Throughout the ForeFlight app, indicated altitude is referred to as baro-corrected pressure altitude, baro altitude, or BARO ALT."
​
 
RV8JD said:
Note that ForeFlight can display Baro Altitude (when connected to an ADS-B In device equipped with a barometric pressure sensor), in addition to GPS Altitude and AGL Altitude.

https://support.foreflight.com/hc/e...-Can-I-view-indicated-altitude-in-ForeFlight-

"The Baro Altitude instrument and the Altitude Tape in the AHRS view can display pressure altitude corrected for local barometric pressure, otherwise known as indicated altitude.

i-22VqZG6-L.png


To display Baro Altitude, ForeFlight must be connected to an ADS-B In device equipped with a barometric pressure sensor, such as a Sentry. (ForeFlight does not use the barometric pressure sensors built into some iOS devices.) It can then use various data types to convert pressure altitude to indicated altitude. These include:

• ADS-B data from an ownship target or nearby traffic.
• Altimeter settings from the nearest METAR report within 100 nm.

Throughout the ForeFlight app, indicated altitude is referred to as baro-corrected pressure altitude, baro altitude, or BARO ALT."
​
Click to expand...

True, but that baro alt is coming from an encoder inside the plane that is also tied into the same static system, so should be reporting the same incorrect altitude.
 
lr172 said:
True, but that baro alt is coming from an encoder inside the plane that is also tied into the same static system, so should be reporting the same incorrect altitude.
Click to expand...

Most EC devices that integrate with EFBs such as Sentry, sky echo etc just vent to cabin for their baro altimetry.
They then adjust based on ADSB transmissions from nearby aircraft if available.
Certainly good enough as a backup.
 
Kind of makes me wonder why we don't have "static port heat" given we have pitot heat. You could turn them both on with one switch if you suspect ice. I suppose it's a combination of 1. static ports aren't directly in the airstream and so are less likely to ice up, 2. we have redundant static ports and the ability to use cabin static pressure if needed, and 3. static heaters would add weight and complexity.
 
I think it’s possible that a lot of frozen static issues in small planes are frozen moisture somewhere in the low points of static lines rather than the port itself freezing over. So heating it may not guarantee reliability.
I know everyone supposedly installs them with the port as the low point but I’ve seen non complying examples.
 
The fuselage tapers rearward where our static ports are located. I don't think ice can form there since it's not facing the airflow.

On airplanes that are not supposed to be anywhere near icing conditions, it's way overkill.

FWIW, on the work plane, the static ports are on the sides of the nose, facing the airflow slightly. It needs to be very dramatic icikg to get ice on the fuselage near the static ports. They are heated, but it's rarely relevant.
 
Richard Connell said:
I think it’s possible that a lot of frozen static issues in small planes are frozen moisture somewhere in the low points of static lines rather than the port itself freezing over. So heating it may not guarantee reliability.
I know everyone supposedly installs them with the port as the low point but I’ve seen non complying examples.
Click to expand...

Absolutely agree, I've seen plenty of static systems in RV's installed incorrectly, the plans show you the correct way.
 
Richard Connell said:
Most EC devices that integrate with EFBs such as Sentry, sky echo etc just vent to cabin for their baro altimetry.
They then adjust based on ADSB transmissions from nearby aircraft if available.
Certainly good enough as a backup.
Click to expand...

My transpoder (ADSB source) gets it's air data from the EFIS which is tied to the static system and suspect many are set up this way. I suggest confirming baro source before trusting this as a backup. I always thought most of these ADSB devices were sniffing the transponder output to get altitude and thought most encoders were tapped into the static system. How could you pass a 2 year transponder check if the alt wasn't tied to the static system? I can't see how the FAA would be ok with Mode C alt data coming from the cabin instead of a static source, as that is not a reliable source and would vary widely by aircraft type. It is also not testable, so why require biannual testing? Maybe I am missing something here.
 
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I believe the transponder/"encoder" is fixed to a baro of 29.92. If you
sniff a transmission from a transponder you get an altitude based on 29.92
baro altitude......
 
Abbreviation of Barometric and Barometer

Flyingleap said:
I believe the transponder/"encoder" is fixed to a baro of 29.92. If you
sniff a transmission from a transponder you get an altitude based on 29.92
baro altitude......
Click to expand...

Don’t confuse “baro”used to refer to static or barometric pressure with “baro” used to refer to barometer setting. Yes, Mode C transponders and ADSB that uses the transponder data transmit “pressure altitude” which is, as you stated, altitude with reference to standard 29.92 inHg. Even though the Mode C transponder doesn’t need to know the current altimeter barometer setting it still receives encoded static pressure measurement from an air data source to be able to transmit your actual pressure altitude.

Skylor
 
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lr172 said:
My transpoder (ADSB source) gets it's air data from the EFIS which is tied to the static system and suspect many are set up this way. I suggest confirming baro source before trusting this as a backup. I always thought most of these ADSB devices were sniffing the transponder output to get altitude and thought most encoders were tapped into the static system. How could you pass a 2 year transponder check if the alt wasn't tied to the static system? I can't see how the FAA would be ok with Mode C alt data coming from the cabin instead of a static source, as that is not a reliable source and would vary widely by aircraft type. It is also not testable, so why require biannual testing? Maybe I am missing something here.
Click to expand...

I’m talking about portable EC (electronic conspicuity) devices, not the ships installed transponder.
 
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