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AOA Pitot: Heated or not

rolivi

rolivi

Well Known Member
Sponsor
I'm very interested in installing a Dynon AOA Pitot. I go back and forth about heated or not because of the price diffence of both purchase and installation. (All my work is done by an A&P)

My EFIS is a D100. My understanding is that the D100 uses the same pitot as the HDX or AFS use. (so I'm good for upgrade when the D100 eventually goes Tango Unform)

I'm a fledgling IFR pilot and my intention is to be able to reduce my no-fly days by being able to punch out, fly over the mess, and land. I don't want to be LIFR or spend long times in IMC... just transistioning.

So... am I penny wise to opt for the non-heated version? Does it effect resell? Do you have heated and not need it? Do you have unheated and wish you had it?

Thanks,
 
If you plan to fly any time in IMC then I’d say a heated pitot tube is a necessity. You should never go into known icing conditions but sometimes it happens despite your best intentions. You don’t want to lose your airspeed and AOA when you are picking up ice and can’t see out of the plane.
 
Nobody ever said IFR is cheap. I notice you used EFIS in the singular. Do you have any other attitude backups? If no, then you have even bigger problems to deal with. How old is your EFIS? If you go back in time far enough, the Dynon EFIS needed airspeed data to reach an attitude solution. Might be time for that upgrade you mentioned.
 
rolivi said:
Do you have heated and not need it?

Thanks,
Click to expand...
BTW, the answer to the above question is, "Who knows?". The heated pitot is controlled by a temperature sensor, so if I was in conditions where I might have had pitot ice I really wouldn't know, since the heat is "automatic" (assuming I don't forget to turn it on).
 
BobTurner said:
BTW, the answer to the above question is, "Who knows?". The heated pitot is controlled by a temperature sensor, so if I was in conditions where I might have had pitot ice I really wouldn't know, since the heat is "automatic" (assuming I don't forget to turn it on).
Click to expand...
Garmin makes two types of heated pitot/AoA tubes. One is just a heater and is always on, another has a temperature sensor and the heater cycles to achieve a preset temperature. I have the always on one because it is cheaper and I dont think the electrical savings from a temperature controlled one was worth the effort.
 
PilotjohnS said:
Garmin makes two types of heated pitot/AoA tubes. One is just a heater and is always on, another has a temperature sensor and the heater cycles to achieve a preset temperature. I have the always on one because it is cheaper and I dont think the electrical savings from a temperature controlled one was worth the effort.
Click to expand...
I have a Dynon unit which is thermostatically controlled, because many years ago I forgot to turn my ‘always on’ pitot heat off. Tying down the plane, I brushed against the pitot - and burned the skin off the back of my hand. Never again. Also - although I have no proof - I hope the thermostat-controlled heater will last longer than the always on units.
 
Please, please, please! Install a heated pitot AND an alternate static air source. Turn pitot heat ON when commencing takeoff roll, turn OFF when exiting the runway. Yes, even in VMC conditions, get into the habit now. Bad stuff happens very, very fast and you do not need to be trouble shooting erroneous data when IMC, especially single pilot. I'm sure folks with even more time than I will tell you about; inversions, supercooled rain droplets falling out the bottom of a TCU, and occluded front mis-adventures to name a few. I think there was a post about a fellow in a well equipped glass RV-9 coming out of Cleveland (my early stomping ground) about a month or so ago. He is still alive, his airplane still in one piece and a family he was able to go home to. (sorry - old fart ramble)
 
Dr_Dave_MT said:
Turn pitot heat ON when commencing takeoff roll, turn OFF when exiting the runway.
Click to expand...
Is there any downside to this besides the current draw?

I was previously taught to turn heat on if it looked like we were soon entering IMC, and that's what I continue to do to this day.
 
rolivi said:
I'm very interested in installing a Dynon AOA Pitot. I go back and forth about heated or not because of the price diffence of both purchase and installation. (All my work is done by an A&P)

My EFIS is a D100. My understanding is that the D100 uses the same pitot as the HDX or AFS use. (so I'm good for upgrade when the D100 eventually goes Tango Unform)

I'm a fledgling IFR pilot and my intention is to be able to reduce my no-fly days by being able to punch out, fly over the mess, and land. I don't want to be LIFR or spend long times in IMC... just transistioning.

So... am I penny wise to opt for the non-heated version? Does it effect resell? Do you have heated and not need it? Do you have unheated and wish you had it?

Thanks,
Click to expand...

Even the professionals struggle to survive a pitot blockage.

Pitot heat will save your life.
 
After start - pitot heat ON
Shutdown - pitot heat OFF

Very simple.

The unregulated probe draws around 10 amps all the time. The Regulated unit is a variable load based on temperature so it doesn’t draw much when it’s warm, and only draws around 10 when it is cold.
 
In Canada for IFR equipment the regulations state the following:
  • (f) a means of preventing malfunction caused by icing for each airspeed indicating system;

The would require a heated pitot for IFR flight. Not sure if the US regs are the same. I would suggest the added safety factor outweighs the additional cost.
 
BobTurner said:
Nobody ever said IFR is cheap. I notice you used EFIS in the singular. Do you have any other attitude backups? If no, then you have even bigger problems to deal with. How old is your EFIS? If you go back in time far enough, the Dynon EFIS needed airspeed data to reach an attitude solution. Might be time for that upgrade you mentioned
Click to expand...
Backup attititude is provided by a Gemini ADI https://sarasotaavionics.com/avionics/gemini-adi (with it's own backup battery)

Thanks for the thought.
 
tass said:
Is there any downside to this besides the current draw?

I was previously taught to turn heat on if it looked like we were soon entering IMC, and that's what I continue to do to this day.
Click to expand...
Only downside I can think of is when one losses an alternator and is running on battery power. So short of an emergency, can't think of a downside with a well designed and executed electrical system. My pitot heat is on the master switch, so it wont stay on if I forget to turn it off. But I make sure it is off because it will drain the battery during start before the engine fires up. And during tie down, I cant accidentally hit it because it is behind the leading edge and I check to make sure it is not too hot before putting the pitot cover on.
 
tass said:
Is there any downside to this besides the current draw?

I was previously taught to turn heat on if it looked like we were soon entering IMC, and that's what I continue to do to this day.
Click to expand...
#1 No. Once airflow is over pitot, no danger of overheating. #2 You'll forget, it takes a while to come to temp also.
 
Thanks! I just double checked the details of the Dynon one, and it seems it's regulated so there's no issue with overheating even when on the ground.
 
tass said:
Thanks! I just double checked the details of the Dynon one, and it seems it's regulated so there's no issue with overheating even when on the ground.
Click to expand...
FWIW, when I installed my dynon heated pitot in the wings in the cradle I tested it. Heated to around 65 Celcius, drawing around 5-6A, though obviously in the air it would be different.
 
bmellis11 said:
If you plan to fly any time in IMC then I’d say a heated pitot tube is a necessity. You should never go into known icing conditions but sometimes it happens despite your best intentions. You don’t want to lose your airspeed and AOA when you are picking up ice and can’t see out of the plane.
Click to expand...
I agree 100% with this post. You might not know what the temp in the cloud (or any visible moisture) will be when you fly into that visible moisture. If you are planning to fly IFR, you should have an installed pitot heat system and use it on any IFR flight that involves cloud or visible moisture penetration.

If your plan is VFR only, then no, it’s not required, or in most cases not needed, but you should be aware that if you inadvertently fly into weather in cold conditions, you may loose airspeed indications, and possibly other systems and should have a plan to cope with this.
 
Scott Hersha said:
I agree 100% with this post. You might not know what the temp in the cloud (or any visible moisture) will be when you fly into that visible moisture. If you are planning to fly IFR, you should have an installed pitot heat system and use it on any IFR flight that involves cloud or visible moisture penetration.

If your plan is VFR only, then no, it’s not required, or in most cases not needed, but you should be aware that if you inadvertently fly into weather in cold conditions, you may loose airspeed indications, and possibly other systems and should have a plan to cope with this.
Click to expand...
With all the various discussions on risks, why would anyone NOT have a heated pitot, and more important, use it?

It is simple, proven, and has no downside.
 
rocketman1988 said:
With all the various discussions on risks, why would anyone NOT have a heated pitot, and more important, use it?

It is simple, proven, and has no downside.
Click to expand...
I agree - mostly……. There is, of course, a downside that you probably don’t agree with - Cost, complexity, and weight. I have the standard kit supplied bent SS pitot tube on my current (and last) RV, and also had that on my two RV4’s that I didn’t build. I don’t plan on ever flying in icing conditions, but if I somehow get onto weather that can cause an iced pitot tube, I’m confident that it won’t be a problem. The OP says he is a fledgling IFR pilot, and so yes, he should definitely install a heated pitot tube. There are some of us that are no longer at that point in our flying careers, and have no reason to install pitot heat. Some may say “what about resale value?” I didnt build this airplane for someone else, and I honestly don’t think it would affect resale value on an RV6. But, with that in mind, and even though I never intend on selling this airplane, I installed wiring out to the bay in my left wing where a heated pitot can be installed - just in case. I’ve told all of my grandchildren that whichever one learns to fly first, I will give them my airplane, and my hangar. And yes, if they want a heated pitot, I will buy and install that for them too (if I can still bend over by then).
 
I wouldn't fly an airplane in IMC without heated pitot, an alternate static source, and a backup AHRS. Some people will, but that's my risk tolerance and I think it's pretty mainstream. So yeah, from a resale standpoint, if you're selling an airplane and say it's IFR capable, most people are going to expect it to have pitot heat.

My checkbook was suffering Garmin overload when it was time to buy a pitot tube, so I went with the heated but unregulated version. No fancy thermostat, it's just on or off. I have it wired so it throws a CAS message to remind me to turn it off when appropriate.

The cost difference between the unheated VFR version and the one I have was literally the cost of a tank of gas, so I can't imagine a scenario where I can afford an IFR airplane, but can't afford a heated pitot. For alternate static, I went with the Steinair toggle fitting which was a whopping $20.
 
RV7 To Go said:
In Canada for IFR equipment the regulations state the following:
  • (f) a means of preventing malfunction caused by icing for each airspeed indicating system;

The would require a heated pitot for IFR flight. Not sure if the US regs are the same. I would suggest the added safety factor outweighs the additional cost.
Click to expand...
FYI (also in Canada) heated pitot is also required for Night VFR.
 
jaypay said:
FYI (also in Canada) heated pitot is also required for Night VFR.
Click to expand...
If you are flying out here in the southwest USA at night, night VFR IS IFR, because it is one giant black hole; might as well be in clouds because there is no difference.
 
Scott Hersha said:
I agree - mostly……. There is, of course, a downside that you probably don’t agree with - Cost, complexity, and weight. I have the standard kit supplied bent SS pitot tube on my current (and last) RV, and also had that on my two RV4’s that I didn’t build. I don’t plan on ever flying in icing conditions, but if I somehow get onto weather that can cause an iced pitot tube, I’m confident that it won’t be a problem. The OP says he is a fledgling IFR pilot, and so yes, he should definitely install a heated pitot tube. There are some of us that are no longer at that point in our flying careers, and have no reason to install pitot heat. Some may say “what about resale value?” I didnt build this airplane for someone else, and I honestly don’t think it would affect resale value on an RV6. But, with that in mind, and even though I never intend on selling this airplane, I installed wiring out to the bay in my left wing where a heated pitot can be installed - just in case. I’ve told all of my grandchildren that whichever one learns to fly first, I will give them my airplane, and my hangar. And yes, if they want a heated pitot, I will buy and install that for them too (if I can still bend over by then).
Click to expand...
You’d be correct. No one that has an RV ever plans to be in icing conditions but that doesn’t preclude it from happening. You can say you’d be ok but I would be interested in seeing how you react to those conditions and have an iced pitot. I can tell you, from experience and training, that it isn’t an easy task. We can just leave it at that. As for complexity, you state that you already ran the wiring, so it isn’t about that…which leaves cost as your primary factor. To me, the trivial extra cost isn’t worth the risk. The beauty of the hobby, though, is everyone is free to do what they please.
 
rocketman1988 said:
With all the various discussions on risks, why would anyone NOT have a heated pitot, and more important, use it?

It is simple, proven, and has no downside.
Click to expand...
Yep
Desert Rat said:
I wouldn't fly an airplane in IMC without heated pitot, an alternate static source, and a backup AHRS. Some people will, but that's my risk tolerance and I think it's pretty mainstream. So yeah, from a resale standpoint, if you're selling an airplane and say it's IFR capable, most people are going to expect it to have pitot heat.

My checkbook was suffering Garmin overload when it was time to buy a pitot tube, so I went with the heated but unregulated version. No fancy thermostat, it's just on or off. I have it wired so it throws a CAS message to remind me to turn it off when appropriate.
Click to expand...
Agree with all that too.
My only observation would be that they chew a lot of power if unregulated.
In almost all new builds now, an unregulated pitot is going to be the biggest power hog in the aircraft - possibly by a long way.
Aside from it sucking more generating capacity- having 10A up to the panel running constantly seems overkill.
My only ever smoke in the cockpit was a poor quality toggle switching an unregulated pitot.
My 10 has a regulated pitot with some other electrical design changes as a result.
 
rocketman1988 said:
You’d be correct. No one that has an RV ever plans to be in icing conditions but that doesn’t preclude it from happening. You can say you’d be ok but I would be interested in seeing how you react to those conditions and have an iced pitot. I can tell you, from experience and training, that it isn’t an easy task. We can just leave it at that. As for complexity, you state that you already ran the wiring, so it isn’t about that…which leaves cost as your primary factor. To me, the trivial extra cost isn’t worth the risk. The beauty of the hobby, though, is everyone is free to do what they please.
Click to expand...
I could tell you how I reacted to the only time I experienced an iced pitot (at no time was I in IFR conditions), but I think at this point it’s futile. My experience and training made it a non-event. However, that was on my first RV8, which had a VFR glass panel. After that flight I built a new IFR panel for my one year old airplane, and of course installed a heated pitot tube. Installing the wires in my current RV6 took about 5 extra minutes during construction, still leaving about 90% of the work installing a new pitot to be done In a completed wing.
 
rocketman1988 said:
You’d be correct. No one that has an RV ever plans to be in icing conditions but that doesn’t preclude it from happening.
Click to expand...
I've never yet intentionally ventured into ice in either the RV or the C-172, but I've found myself in ice anyway close to a dozen times in my flying career. Anyone who has an IFR rating and actually USES it, for real, will eventually find themselves in ice at some point.

Put the heated pitot in. Failing to plan is planning to fail.
 
Richard Connell said:
Yep

Agree with all that too.
My only observation would be that they chew a lot of power if unregulated.
In almost all new builds now, an unregulated pitot is going to be the biggest power hog in the aircraft - possibly by a long way.
Aside from it sucking more generating capacity- having 10A up to the panel running constantly seems overkill.
My only ever smoke in the cockpit was a poor quality toggle switching an unregulated pitot.
My 10 has a regulated pitot with some other electrical design changes as a result.
Click to expand...
I used the same design practice as I would for other high current draw items: my pitot heat switch is a 15a toggle with two contacts operating in parallel , so even if I have one high resistance contact, I am still properly derated. As with anything, high current is not to be feared, just dealt with properly.
 
One nice thing about regulated pitot heaters I don't think has been mentioned here is that they can provide feedback about the actual pitot temperature... or at least the one I installed does. It's an easy way to know that your pitot heat is actually working, for the small cost of adding one extra wire. Yes with an unregulated heater you can watch for a current rise, but a discrete signal is a bit more elegant.
 
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