Sounds similar to Yaros from Mallorca. If you want to fly, you’ve got no choice but to fly in high humidity. Yaros noted he’s seen rust on his drone. Have you seen any? Thanks for your response.
Is anyone else nervous about flying in very high humidity?
- Thread starter Dbez1
- Start date
Sorry, just one more story related to engine performance and cold intake air vs. hot air.
My old BMW E30 is fuel injected, so no carburettor. But it still has a throttle body and therefor is just as susceptible to throttle icing.
You'd think, how is that even possible with a hot engine running in a tight engine compartment with the hood closed? Sure the entire engine compartment is hot, but the only thing that really matters is the air temperature crossing the throttle plate. Depending on the pressure drop across the throttle plate, right there it's possible for the temperature to fall below freezing even when it's much warmer outside.
If you're running the engine with wide-open throttle applications, it's no issue because at wide-open there is very little pressure drop. It's more liable to ice up at only partially open throttle settings, and generally only if left to run like that for a long enough time without moving the throttle.
Perfect conditions for that would be, for example, at steady cruising speed, at steady partial throttle, for long periods on the highway.
Those clever German engineers eliminated any possibility of throttle icing occurring by fitting the BMW engine with a throttle body heater! There is a small coolant line running directly to/from the throttle body, circulating hot engine coolant around the throttle body.
Typically, all the cool kids recommend one should remove or bypass that coolant circuit altogether, because obviously the engine will run stronger on cold air versus heated air!
Except, they don't get it. Here the engine coolant is heating only the metal body of the throttle assembly. It has practically zero effect on the temperature of the air flowing into the engine.
A more practical reason for bypassing that coolant line is that the cork gasket sealing the heating unit to the throttle body is a notorious source of leaking coolant. Still, the heater is there for a perfectly good reason.
My old BMW E30 is fuel injected, so no carburettor. But it still has a throttle body and therefor is just as susceptible to throttle icing.
You'd think, how is that even possible with a hot engine running in a tight engine compartment with the hood closed? Sure the entire engine compartment is hot, but the only thing that really matters is the air temperature crossing the throttle plate. Depending on the pressure drop across the throttle plate, right there it's possible for the temperature to fall below freezing even when it's much warmer outside.
If you're running the engine with wide-open throttle applications, it's no issue because at wide-open there is very little pressure drop. It's more liable to ice up at only partially open throttle settings, and generally only if left to run like that for a long enough time without moving the throttle.
Perfect conditions for that would be, for example, at steady cruising speed, at steady partial throttle, for long periods on the highway.
Those clever German engineers eliminated any possibility of throttle icing occurring by fitting the BMW engine with a throttle body heater! There is a small coolant line running directly to/from the throttle body, circulating hot engine coolant around the throttle body.
Typically, all the cool kids recommend one should remove or bypass that coolant circuit altogether, because obviously the engine will run stronger on cold air versus heated air!
Except, they don't get it. Here the engine coolant is heating only the metal body of the throttle assembly. It has practically zero effect on the temperature of the air flowing into the engine.
A more practical reason for bypassing that coolant line is that the cork gasket sealing the heating unit to the throttle body is a notorious source of leaking coolant. Still, the heater is there for a perfectly good reason.
The owners manual explains the the details of what acceptable humidity is for your drone. Every drone I have ever owned which is 9 has this explained.
I've flown all over the world in many humid climates ranging from Africa, the Congo, Africa, Louisiana, You name it...You just need to understand how humidity effects flight. Has no baring on German made cars. We are talking about flight not driving. Very different things. This is explained well if you take the part 101 courses offered online. Or just research it.
Thank you but I understand the effect humidity has on flight. I’m interested in the possible negative effect on the DRONE in the real world, as Yaros and others responded earlier in this thread.The owners manual explains the the details of what acceptable humidity is for your drone. Every drone I have ever owned which is 9 has this explained.
I've flown all over the world in many humid climates ranging from Africa, the Congo, Africa, Louisiana, You name it...You just need to understand how humidity affects flight. Has no baring on German made cars. We are talking about flight not driving. Very different things. This is explained well if you take the part 101 courses offered online. Or just research it.
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I have a dehumidifier cabinet for some of my camera gear. If I ever fly in humid conditions I'll put the drone in there for a couple days to dry it out. I also have several packets of desiccant in my hard case to keep the moisture out. One thing about flying in humidity is that you don't know how much has been sucked in by the cooling fans and is just sitting on the circuit boards when you're done flying. I figure it can't hurt to put it in the cabinet. If it's good enough to keep moisture out of your lenses it's got to be good for the drone as well.
FLDave
Well-Known Member
I think there are 2 distinct issues discussed: high relative humidity and clear air and 100% humidity with visible moisture.
With warm weather (Florida) and no visible moisture there is not a concern as long as the drone and air temperature are the same, so no condensation on internals. This also assumes that the drone is stored in a climatized area where the relative humidity is considered "dry"; it depends on the temperature.
I have no concerns flying in high relative humidity (less than 100%. The real problem, however, is that very little skin evaporation can occur to it is extremely uncomfortable and hot when perspiration cannot evaporate when the temperature is high along with relative humidity.
With warm weather (Florida) and no visible moisture there is not a concern as long as the drone and air temperature are the same, so no condensation on internals. This also assumes that the drone is stored in a climatized area where the relative humidity is considered "dry"; it depends on the temperature.
I have no concerns flying in high relative humidity (less than 100%. The real problem, however, is that very little skin evaporation can occur to it is extremely uncomfortable and hot when perspiration cannot evaporate when the temperature is high along with relative humidity.
Just out of curiosity, what details exactly does your owner's manual explain is an acceptable humidity for your drone?
I have an original Phantom, a Phantom 3 Pro, and a Mavic Mini. I searched the manual of the Phantom and it makes no mention at all of humidity, moisture, wetness, or anything like that.
The manual for the Mini only mentions "humidity" twice. Once in reference to the Downward Vision System where it warns to;
And once in reference to the camera, where it says;
Neither reference specifies what would be considered a suitable or acceptable % relative humidity. I suspect they mean anything greater than 100% where actual droplets of water might obstruct the lens.
The Phantom 3 Pro manual also makes no mention whatsoever of "humidity". With reference to the Vision Positioning System, the closest it gets is;
Can you provide a quote from any of your nine drone manuals explaining how humidity affects it?
Exactly. You can have 99% relative humidity in cold air or warm air. At 99% it's still absorbed in the air. When it reaches 100% it will condense out as visible water droplets.
Every time you exhale, your breath carries moisture away from your lungs. If you are inside a warm house, or step outside into warm air, you won't see that moisture because warm ambient air (unless it's already at 100% relative humidity) will easily absorb the moisture from your breath.
But if you step outside into frigid air, your exhaled breath produces a cloud of visible droplets in the air. That's because cold air can only absorb a small amount of moisture. Your warm exhaled breath contains moisture at some % relative humidity less than 100%. But as it rapidly cools in the frigid air, the relative humidity suddenly exceeds 100% and the moisture condenses out as visible droplets.
A similar thing happens when you step from the cold outside into a warm humid room. The warm air inside can hold a greater quantity of moisture than the cold air outside. But you don't see it in either environment unless the % relative humidity goes over 100% in either place. But if you carry cold items (cameras, drones, eye-glasses) from the cold outside into the humid warm environment inside, wherever that warm humid air touches those cold surfaces and cools the air, moisture will condense onto the cold surfaces. If your lenses are cold enough, you get frost forming. If they're only just cool enough, you get just fog.
LoudThunder
Part 107 Licensed
Here is a more concise explanation of flying around clouds. It is also in the FAA Advisory Circular, AC No: 107-2A, Subject: Small Unmanned Aircraft System (Small UAS), Date: 2/1/21.
It also addresses those instances of folk who fly their drone above the clouds… And make no mistake about it, FOG is a CLOUD, one is on the ground, the other is not… And another point is when the drone is above the fog, it is not in your line of sight…
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