Flying above freezing level in clear conditions

[Ryanm]

This doesn’t have to be so difficult.

clear of cloud will almost certainly keep you clear of icing. If you go through some rain, you could pick some up. Just stay clear (inclusive of required margins), you’re VFR. 

[skippydiesel]

25 minutes ago, Ryanm said:

This doesn’t have to be so difficult.

clear of cloud will almost certainly keep you clear of icing. If you go through some rain, you could pick some up. Just stay clear (inclusive of required margins), you’re VFR. 

Rightly or wrongly I was taught that passing through rain is "technically" entering cloud - its pedantic I know however if the intention, of the clear of cloud rule for VFR pilots, is about being safe from all aspects of cloud flying (not jus a loss of visibility) then avoiding rain becomes part of the intent.

 

I have (in the UK) experienced freezing rain (sleet freezing on contact with a car windscreen) conditions but never heard of it in Australia

[Roundsounds]

 

1 hour ago, skippydiesel said:

Rightly or wrongly I was taught that passing through rain is "technically" entering cloud - its pedantic I know however if the intention, of the clear of cloud rule for VFR pilots, is about being safe from all aspects of cloud flying (not jus a loss of visibility) then avoiding rain becomes part of the intent.

 

I have (in the UK) experienced freezing rain (sleet freezing on contact with a car windscreen) conditions but never heard of it in Australia

Hmmm, not sure why you’d be led to believe rain was technically cloud. 
cloud is cloud, rain is rain, snow is snow, etc. 
It’s a matter of understanding the hazards associated with various types of weather. Sometimes rules of thumb become law in people’s minds. It’s healthy to question why we do things and study appropriate material to develop an understanding of the subject. Weather and aviation are one of the topics pilots should understand. 

[kgwilson]

There are 2 problems with rain. 1 is visibility so depending on how heavy the rain is you may not be able to see where you are going. Light rain usually doesn't cause a problem as the windspeed will disperse the rain from the screen. 2 is propellor damage. Rain is bad for wooden props even glass reinforced wooden props, less so for composite and carbon fibre pros but can still cause damage and not so bad on full metal props  but it will take the paint off and eventually roughen the prop metal surface. If the rain goes solid as in hail that is a very different story.

[facthunter]

Rain is not cloud. Fog or mist is much the same as cloud except cirrus clouds are ice already and don't wet anything. You only get them at quite high altitudes. Flying through snow won't wet much if it's cold enough. The "V" in VFR is visual and that's about seeing where things are. Large raindrops can fall in a clear sky as  can hail. There's two types of airframe icing spoken of in aviation Ryme and clear. Ryme tends to impact forward facing areas and can be very irregular and muck up airflow

 Regarding surface damage. of rain, velocity of the drops play the most part so with wooden props slow the revs and get out of the rain   Rain can damage metal also  where speeds get to around 400 mph the surface can be etched severely by the water.  With a propeller that figure is arrived at considering Diameter of prop and forward speed and prop RPM.

  Hail can come from anvil Cloud from the top of a big Cumolo Nimbus cloud. when you are even some 20 miles away from the main cloud . so just staying VFR isn't enough sometimes.. Heavy rain can reduce the OAT quickly as the subsiding air is from very cold levels at times. Nev

Edited July 10, 2021 by facthunter

[skippydiesel]

Oh goody!!!we have a debate ;

 

• I say ALL precipitation is part of the cloud it comes from ego you fly through precipitation (light or heavy) you are passing through cloud (light/heavy)
• Further - I also say precipitation can not fall from a clear sky (there must be a cloud somewher even if not directly overhead the reciprocation).

 

Lets go to it chaps!

[kgwilson]

Clouds form when water vapour (less dense than air) rises and condenses at an altitude and condition defined as the dew point into a liquid where the droplets are tiny and the density reaches an equilibrium with the surrounding air. When these combine to form larger droplets they become dense enough to be pulled to earth by gravity. The droplets continue to combine as those already formed fall out of the bottom of the cloud which is at the dew point to form. The size of the rain drops depends upon a number of factors including air movement direction, temperature and air pressure which increase the amount of water vapour condensing and the combination into rain drops.

 

So, rain is precipitation which means it is falling from the sky not being suspended in it which is cloud. Precipitation includes snow, sleet and hail. 

[Thruster88]

1 hour ago, skippydiesel said:

Oh goody!!!we have a debate ;

 

• I say ALL precipitation is part of the cloud it comes from ego you fly through precipitation (light or heavy) you are passing through cloud (light/heavy)
• Further - I also say precipitation can not fall from a clear sky (there must be a cloud somewher even if not directly overhead the reciprocation).

 

Lets go to it chaps!

Visibility is zero in cloud. In rain it is often in excess of the legally required 5000 metres for VFR ops.

[facthunter]

You have to pay attention to the   detail. I said rain can fall in a clear sky. Rain drops and hail falls at a terminal velocity depending on the size of the drops. IF there's severe updrafts in an active Cu Nim the updrafts stop the descent of the drops until they get large enough. to overcome the updrafts. I DID say LARGE raindrops and IN a clear sky.. Wind at various heights can TRAVEL IN DIFFERENT DIRECTIONS. Where they mix will often form stratus type clouds. In any  case the drops or pieces of ice may land far from the cloud that helped to form it. The structure of some large hail often indicates it has gone down and up 2 or 3 times  at high altitudes before it finally descended to a low level at a remarkably large  size and mass. A  large drop can be from a piece of Hail that has melted completely or partially. Nev

[APenNameAndThatA]

2 hours ago, skippydiesel said:

Oh goody!!!we have a debate ;

 

• I say ALL precipitation is part of the cloud it comes from ego you fly through precipitation (light or heavy) you are passing through cloud (light/heavy)
• Further - I also say precipitation can not fall from a clear sky (there must be a cloud somewher even if not directly overhead the reciprocation).

 

Lets go to it chaps!

You are going to have to cop the losses on this one.  RA-Aus aircraft are allowed to fly in rain, and can thereby get airframe icing. If rain was cloud, VFR pilots would be required to remain clear of rain. It isn’t and we’re not. 

[facthunter]

Rain if you include all types is probably harder to remain clear of than cloud. Fog can catch you easily if you operate in certain localities and  the slightest film of water on your windscreen can reduce your forward vision to very little usually  later in the day. Being able to land looking out each side is a must. Similar to having a small oil leak from the engine, Loss of vision isn't only being in an obvious cloud. Nev

[skippydiesel]

2 hours ago, kgwilson said:

Clouds form when water vapour (less dense than air) rises and condenses at an altitude and condition defined as the dew point into a liquid where the droplets are tiny and the density reaches an equilibrium with the surrounding air. When these combine to form larger droplets they become dense enough to be pulled to earth by gravity. The droplets continue to combine as those already formed fall out of the bottom of the cloud which is at the dew point to form. The size of the rain drops depends upon a number of factors including air movement direction, temperature and air pressure which increase the amount of water vapour condensing and the combination into rain drops.

 

So, rain is precipitation which means it is falling from the sky not being suspended in it which is cloud. Precipitation includes snow, sleet and hail. 

Just to keep the debate on the move - "water vapour (less dense than air) - Naaa! warm/hot air rises and being hot can carry more water vapour than cold air - the water vapour (invisible) condenses,  in to tiny droplets, as the hot air cools, forming clouds.  Rain develops when these droplets start to combine (often around a microscopic dust nucleus). The stronger the hot air rising (updraft) the longer the droplets/rain will stay airborne, forming ever larger droplets.

 

Snow is just frozen rain that has nor gone through the cycles below

 

Hail is formed when the droplets/rain meet very cold air and freeze - again the greater the updraft the longer the hail will be suspended, rinsing an falling through warming/cooling cycles and growing ever lager (large hail).

 

Sleet is a rain/snow combined.

 

You can see through wispy light clouds - does this mean its OK for a VFR pilot to fly through?

 

You can see through light rain /mist at what point did it cease to be cloud allowing you to fly through?

 

You can see through light blowing snow - OK to fly through ?

 

When it becomes opaque - still OK to fly through?

 

If precipitation, in all it forms, comes from cloud at what point is it no longer cloudse and the VFR pilot can fly through it?? 

[Thruster88]

I get what you are saying Skippy, this recent flight with low cloud and light rain is a good example. Would I have continued if the only option was the rain showers on the right, no way. Fine rain drops on the screen definitely make things worse as Facthunter mentioned. As always 10 mins later on the ground the weather was beautiful.  

[skippydiesel]

Great photos Thruster88

[kgwilson]

 

 

I should have said  less dense than dry air because water vapour becomes an integral part of the air until the dew point is reached and it condenses. It doesn't have to be warm to rise if the air above it is dry.

 

At 18 atomic units, water vapor is lighter than diatomic Oxygen (32 units) and diatomic Nitrogen (28 units). Thus at a constant temperature, the more water vapor that displaces the other gases, the less dense that air will become.

 

In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds.

Edited July 10, 2021 by kgwilson

[Old Koreelah]

10 hours ago, kgwilson said:

…Thus at a constant temperature, the more water vapor that displaces the other gases, the less dense that air will become...

That makes sense, but is opposite to my experience riding in rain and 100% humidity, when I’d always get my best fuel economy…

But maybe that had more to do with more careful twisting of right wrist.

[RFguy]

WelI, I got my first misty flying (J230D) on Friday in OAT=12, misty, drizzle, intermittant sparse raindrops,  ceiling = 750 AGL, slightly fogged windscreen on taxi/TO. The wet, foggy windscreen certainly affects visibility around the airport, and seems to change depth perception  and attitude perception on TO.  - IE so that's another thing that gets affected flying in most weather, depth perception and general visibility. Even though I had sufficient horizontal vis to meet VMC if my head was OUT of the aircraft, inside, the water on the windscreen makes for quite a difference in judgement and what you can see., and would likely affect ability to get nav fixes . I'd say that if flying above BKN looking for holes and ground nav fixes, that WITH the mess on the windscreen, that would probably be drawing a long bow, and in that condix, perhaps flying over FEW would be the limit.

 

windscreen material compatible anti raindrop etc coating might assist in these cases.
(now 12 hours on type , since engine rebuild) 

 

 

Edited July 11, 2021 by RFguy

[facthunter]

The stuff for motorcycle visors is ok,but how (and when) are you going to apply it?  You usually don't have foreknowledge if you are a fair dinkum VFR operator and not a  seasoned  scud runner.. PROPERLY equipped IFR planes have squirters that distribute the additive concentrate over the screens  by the rain and wipers. If the rain disappears as you do it the whole lot smears the windscreen. Besides creating a significant hazard that makes you look like a grade "A" novice.. Nev

[skippydiesel]

For RFguy - When I were a wee lad we used a freshly cut spud, wiped over, on the windscreen. I guess the starch effected the surface tension of the rain drops causing them to run together. The effect is to improve visibility - wipers would be 110% better. I can just see you reaching out of the cockpit at 2000 ft, 110 knots,  with half a spud in hand gamily wiping over the rai effected windscreen😁

[Roundsounds]

12 hours ago, RFguy said:

WelI, I got my first misty flying (J230D) on Friday in OAT=12, misty, drizzle, intermittant sparse raindrops,  ceiling = 750 AGL, slightly fogged windscreen on taxi/TO. The wet, foggy windscreen certainly affects visibility around the airport, and seems to change depth perception  and attitude perception on TO.  - IE so that's another thing that gets affected flying in most weather, depth perception and general visibility. Even though I had sufficient horizontal vis to meet VMC if my head was OUT of the aircraft, inside, the water on the windscreen makes for quite a difference in judgement and what you can see., and would likely affect ability to get nav fixes . I'd say that if flying above BKN looking for holes and ground nav fixes, that WITH the mess on the windscreen, that would probably be drawing a long bow, and in that condix, perhaps flying over FEW would be the limit.

 

windscreen material compatible anti raindrop etc coating might assist in these cases.
(now 12 hours on type , since engine rebuild) 

 

 

I’m thinking you need to revise the rules if you think you can use visual fixes to navigate above BKN cloud. If you’re flying under RAAus rule set you cannot use navaids for position fixing. 

Edited July 11, 2021 by Roundsounds

[RFguy]

Hi Skippy

Interesting on the spuds.  Cant open the door while flying in the J230. Although I see many GA aircraft do have a door/ window open/off spec, useful for the spud application... But you cant reach it in harness. 

 

Anyway, there is little chance of seeing another plane flying around with the mess on a windscreen without wipers- ---that's a fair hazard.

 

I noticed that after bringing the aircraft significantly below the cloud layer in circuit, you get the horizon visible again and then you get contrast between the planes flying around against the 'brighter far sky', if I can call it that. 

 

Still learning lots of useful things every flight -  (my 12 hours on type  have 95% been with instructor) in less than NCD.  In the J230, once you get airspeed + cabin heat, fogging is no issue .  

 

[MattP]

I must say I do find the thread drift on some of these topics confusing. We start out in a discussion about flying above freezing level in clear conditions, segway to rain being cloud or not and then onto putting potato on your windscreen.

 

I do worry that given this is a student forum that some might actually read this and consider some of these strategies.

 

To that end, since the conversation is based on an RAA context, why not make it simple? Others have put some well constructed and technically accurate answers to cloud and rain, but I thought simplifying it would also help in case someone actually reads this looking for advice.

 

Rain = rain wet stuff falling from the sky - can vary in how much wet stuff falls and how big the wet stuff is. You can fly through this VFR, although the regs assume you're smart enough to decide whether you should or not (its the pilot part of being a pilot).

 

Cloud  = wet stuff suspended in the sky... you don't really need to worry too much about these as a RAA pilot, you need to stay away from them, even the rules tell you to. Don't go in them, don't be tempted to fly VFR "on top" above a BKN layer. If you do, go and read any one of the multitude of reports written about the last intrepid aviator that did so without the proper training.

 

ICE = good in drinks, bad on your aircraft, you can get it in clouds (should not be there anyway). You can also pick it up if the OAT is ~ 0 and its raining / drizzling (cold soaked airframe) [looking at you Tas, Vic and ACT winters]. Likes to accumulate on sharp / pointy things first - pitot probes are a favourite, wing struts / horizontal stabilisers also good (especially worth looking for in a Jab / other high wing where you can't really see it). Your RAA aircraft will likely not be equipped to handle this as it may not have the right equipment, after all the designers didn't expect you to be flying around in icing conditions....

 

If the ceiling is 750ft raining, BKN/ OVC cloud etc, I'd personally admire the plane in the hangar, or on the ramp, make a cuppa and find someone to talk to about flying as I have nowhere so important to be flying to, that as a private or recreational pilot I need to be.

 

As a bit of context, the circling minima for my local airfield is 720ft and I wouldn't contemplate departing IFR below that even though technically the approach minima straight in are lower. Just a personal minimum, and that's with a suitably equipped aircraft. VFR, nah.. got better things to do and its outside my personal minimums.

 

YMMV.

 

 

 

 

 

 

 

[skippydiesel]

On 12/07/2021 at 12:16 PM, MattP said:

I must say I do find the thread drift on some of these topics confusing. We start out in a discussion about flying above freezing level in clear conditions, segway to rain being cloud or not and then onto putting potato on your windscreen.

 

I...................................................................................................................................................................................................................................................................................................................................

 

As a bit of context, the circling minima for my local airfield is 720ft and I wouldn't contemplate departing IFR below that even though technically the approach minima straight in are lower. Just a personal minimum, and that's with a suitably equipped aircraft. VFR, nah.. got better things to do and its outside my personal minimums.

 

YMMV.

 

 

Hi MattP,

 

I agree there can be significant (amazing) "thread drift" - this is very much part of the free conversation style of this Forum and a characteristic I very much enjoy.

There should be no confusion, if you read from the beginning, as you will see how the conversation has evolved.

Further; usually the opening topic is thrashed out/address pretty comprehensively at the start and only "drifts' as we seek to explore its outer limits & beyond.

Long Live The Thread Drift

[Kununurra]

MattP,

thread-slides, big and small occur regularly but rest assured the forum does provide solutions & not just problems so have a little patience.

Most people place a disclosure clause with their advice but I am sure they all mean well.

Happy reading

cheers

 

[RFguy]

usually threads stay on message until a solution is provided, or there has been discussion on said topic, at least the first page. from then on, there is drift and hangar talk.