Carburettor Icing...

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Carburettor Icing...

Postby Fozzer » Fri Aug 09, 2013 3:50 am

...and its consequences!... :cry: ...!

http://www.flyingmag.com/news/utah-forc ... =obnetwork

Fortunately no serious injuries this time (a rarity!), with the pilot concentrating on landing safely in difficult terrain!

When you are flying your small, normally aspirated, piston prop aeroplanes, how often do you observe atmospheric condition outside of the aircraft during the flight...low temperatures...damp conditions (clouds, fog, mist, rain)...etc....resulting in ice formation inside the carburettor, blocking the air/mixture flow to the engine, causing the engine to stop...
...and under those conditions, how often do you apply carburettor heat, and listen to the response from the engine?

...and apply Pitot heat, to ensure the instruments relying on air pressure (ASI, etc) are reading correctly?

Carburettor Icing is a regular killer of Pilots and their passengers!

Regular application of carburettor heat during flight is highly recommended!

http://www.fly13.co.uk/Tug/Carb%20Ice/Carb%20Icing.htm

Good practice in the Flight School!.... ;) ...!

Paul.....Motorcycles and carburettors!

Tip: Always apply carburettor heat when fully closing the throttle in preparation to land, a time when the temperature of the air in the carburettor venturi suddenly drops below the freezing point, due to the restriction of the airflow.
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Re: Carburettor Icing...

Postby Brian Z » Thu Jan 09, 2014 11:37 am

The "Real-world Weather" option in FSX seems to be hit or miss as far as how often it's updated, I've seen the same weather for weeks at a time sometimes, so I've started using FSRealWX lite. It actually will cause icing in the right conditions-- both airframe and carburetor. Fortunatley, if your carbs do ice, turning the heat on will clear them in a few seconds (in FSX I mean, r/w you'll be making a forced landing).
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Re: Carburettor Icing...

Postby Flying Trucker » Wed Jan 22, 2014 8:02 am

Good morning Paul... <<s

Interesting topic we chew the rag about at the bug smasher field.

Many of us Old Retired Rocking Chair Flying Geezers have a few stories about Carburetor Ice when bashing about the puffy wuffies.

The last Royal Canadian Air Force Dakota/C47/DC3 was lost with all crew when flying a Search and Rescue Mission. The DAK picked up Carburetor Ice at low level and crashed.

Myself, while flying the DC3 I picked up Carburetor Ice on one engine and was very lucky to catch the aircraft as she started to roll. It took full rudder.
We were fully loaded with freight and near the end of a sixteen hour flying day, it was just past midnight and my Number One was napping.

People complained when Transport Canada started to put stiffer restrictions on flying for the airlines but they were all for safety and many of us welcomed those rules and regulations. It would have been nice to have a union when I first started flying but that didn't come about until half way through my flying career.

It would have been nice to have a Flight Engineer on all flights but the Airline I flew for took the Flight Engineer off the Douglas DC3s and Consolidated Canso/Catalina/PBY5A.

Again good topic Paul... ;)
Cheers...Happy Landings...Doug
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Re: Carburettor Icing...

Postby Fozzer » Wed Jan 22, 2014 9:33 am

Hello Doug....

..many thanks for the reply on a subject very dear to my heart!

As a regular Motorcyclist, and owner of vintage Motor Cars, I am well aware of experiencing Carburettor Icing under certain atmospheric conditions, cold, damp weather.

On my Motor cars the effect was to freeze and shrink the aluminium bodies of my SU Carburettors, thereby jamming the close-fitting suction pistons in the chambers, and causing a serious unbalance in the Air/Petrol mixture passed into the engine.

On my Motorcycles the effect was to create ice build-up in the carburettor air intakes, especially at low throttle/high vacuum settings, restricting the air flow, exactly the same as normally aspirated aircraft Carburettors.

It may seem strange, but even in my Flight Simulators, I automatically apply Carburettor Heat when reducing throttle settings prior to landing, and be ready to immediately cancel the setting to obtain maximum power if an abandoned landing and go-around is required,
The effects of Carburettor Icing age are so deadly that it comes as second nature to me now...even though it is not recognised by the Flight Simulators!
And a regular application of Carburettor Heat during the cruise to check for any possibility of ice build-up.

Its reason for the (fatal) crash cannot be ascertained because the ice will have melted by the time the aircraft is inspected!

Many of the amazing Screen shots here, showing small aircraft with normally aspirated engines, appearing in what appears to be very unsuitable weather conditions, unfit for safe flying!

If flying conditions are not suitable for a safe flight, then stay on the ground...(and abandon the screen shot)....trust me!... ;) ...!

Keep a wary eye on those clouds up there...(and watch out for icing/blockage in the Pitot Tube and Static Port affecting your instruments!).

Paul...A Wise Weather Watcher.... :D ...!

P.S...I hate cold, damp weather.!.... :( ...!
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Re: Carburettor Icing...

Postby PhantomTweak » Wed Jan 22, 2014 1:08 pm

P.S...I hate cold, damp weather.!.... ^-^ ...!


Well, then you live in precisely the right part of the world, doncha?? :lol:

Simple fix: Move to Panama, or Iraq, or.... the list goes on! Heck, even Yuma, Az :happy-sunshine: :angry-extinguishflame: is fairly warm most of the time! I lived there for 30 years, and regularly saw temps over 100 in the middle of winter. Hated every minute I was there...ALTHO the weather do make the gals dress rather....thinly? :dance: :handgestures-thumbupleft:

360 flying/biking days a year, just watch out for the wild horses, I hit one myself riding my retired police bike, lost an eye to the whole mess...Most asinine headline in the paper the next day: Horse Dies in Motorcycle Accident! To this day I can't figure out how he got ON the bike in the first place! But carb icing is definately NOT a problem there! :lol:

Anyway, you are right, in all seriousness....Bad juju, carb/pitot icing! definately something to watch out for! Good post, thanks!

Fly warm and safe all!

Pat☺
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Re: Carburettor Icing...

Postby Flying Trucker » Thu Jan 23, 2014 9:06 am

Good morning Pat...will try very hard not to hijack (OOPs) are we allowed to use that word on an aviation forum?) Paul's Thread... <<s

Not sure I could live in a location that does not have snow, freezing rain, below freezing temperatures, high winds and white out conditions during the Winter months... :lol:

Like the other three seasons there is so much to do during the Winter months.

Many locations are much easier to access with a ski/wheel ski aircraft.

We Canucks enjoy our winters... ;)

A topic we chewed the rag about at the local bugsmasher field the other day was about trading in a motor vehicle.

Some of those other Old Retired Rocking Chair Flying Geezers have some ideas of their own.

-Trade in a motor vehicle on a cold rainy day...the engine runs hot and sounds smoother....
-Nine times out of ten the sales person won't spend much time looking at the trade in vehicle in the rain....
-If it is raining they probable won't look in the trunk or lift the engine hood....

When I purchased an aircraft I would look at it two or three times before making up my mind to buy or not and that is usually what I do when purchasing a vehicle, weather never really entered into the equation for purchasing, I have a list of options like for aircraft, de-icing equipment and navigation equipment.
It did not matter if it was raining, snowing or the sun was shining when I made the deal...still...a lot of folks think a motor vehicle should be traded in on a rainy day.... :o :whistle:
Cheers...Happy Landings...Doug
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Re: Carburettor Icing...

Postby Fozzer » Thu Jan 23, 2014 10:47 am

It is a fact, that my motorcycles run much smoother, and I suspect develop a few more brake-horse-power on cold, damp days when the air is full of moisture....

The air is denser, and the combustion effect (pressure) is increased by using the steam provided by the moist air to accelerate the pistons downwards!

Indeed, at one time, direct water injection into the carburettor air intake was used, (and maybe still is!) to achieve the same effect.
(An accessory for motorcycles).

...but I still hate cold, damp days...when I get cold and wet!

But in the market garden of the USA...California...>>> http://www.pbs.org/newshour/bb/nation/j ... 01-22.html
http://www.telegraph.co.uk/news/worldne ... ntury.html

Where I spend most of my time basking in the heat!

Paul.... :D ...!

Water Injection for engines....>>>

http://en.wikipedia.org/wiki/Water_inje ... engines%29
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Re: Carburettor Icing...

Postby aeroart » Thu Jan 23, 2014 2:03 pm

Paul,

I don't agree with all of your last reply. Water adds power only if the fuel is detonating rather than burning normally. When moisture is present in the fuel-air mixture, the moisure replaces a volume of air equal to the moisture's volume. Displaced with that air is the 20% oxygen content contained in the displaced volume. Less oxygen, less power. Engines seem to run smoother and quieter because they're developing less power.

You are right about the "cold" part. Power increases with decreasing ambient temperature; increases air density. What's probably happening with your motorcycle is that the effect of the lower temperature is outweighing the effect of the increased moisture.

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Re: Carburettor Icing...

Postby PhantomTweak » Thu Jan 23, 2014 3:02 pm

I don't know much about water injection on piston engines in aircraft, other than it exists, and I think was used as an emergency power booster when absolutely necessary for survival of the airplane and pilot. Kinda like WEP, I think...Limited of course by the size of the water tank :lol:

I DO know for a fact however that the AV-8A and C model Harrires used in Yuma have to use water injection during the hover. I was there when they first arrived in Yuma and they had all kindsa trouble hovering in the heat until they Installed the water inject system. They even hovered one right into the GA hanger over on civ-side. BIG mess. :shock:

Oh yeah, my father in law worked on the Harrier development team when they were first adapting the Harrier into the Marine Corps. He has all the inside scoop :mrgreen:

But anyway, that's all I know about water injection...teensy, tiny amount indeed. As to vehicles running better in cold, wet weather...No clue, Spent 30 plus years in Yuma! :lol: Cold and wet were definately NOT our normal order of business! :lol: :lol:

Have a wonderfull day all! Warm OR cold!

Pat☺
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Re: Carburettor Icing...

Postby Fozzer » Thu Jan 23, 2014 4:25 pm

More interesting bits and bobs regarding water injection...>>> http://blizzard.rwic.und.edu/~nordlie/w ... round.html

I can remember it was a hot (wet!) subject regarding the engines on my motorcycles during the 1950's when various water injection devices were tried out!

Me?.....I just stuck to good-old-fashioned Amal Carburettors, sucking in oxygen and leaded petrol!
(The Carburettors...not me!).... ;) ...!

Paul....sucking and blowing.... :mrgreen: ...!
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Re: Carburettor Icing...

Postby aeroart » Thu Jan 23, 2014 4:44 pm

Good link, Paul. It filled in the blank spaces.

Pat, I surfed for "water injection jet engines," and found good info on Purdue University's website. Spraying water into the compressor cools the air flow, and the increase in air density increases thrust. Injecting coolant into the combustion chamber increases mass flow through the turbine. Pressure and temperature decreases across the turbine and increases pressure in the jet pipe, giving additional thrust. Turbine inlet temperature also decreases, which allows the fuel system to increase fuel flow, which increases engine rpm, providing additional thrust.

I remember those long, white-knuckle takeoffs in the early jet airliners, even though they had water injection.

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Re: Carburettor Icing...

Postby Brian Z » Wed Feb 05, 2014 3:33 am

For water injection on piston aircraft, the water also has methanol mixed in. I'm not sure if the methanol burns as fuel, or if it's extra cold.
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Re: Carburettor Icing...

Postby TryHinkel » Sat Apr 15, 2017 2:47 pm

Oh, this video angers me to no end. The biggest anger point was flying with a baby in an unsecured infant seat, that is inexcusable. They're extremely lucky the baby was not injured any more than could be expected in such an outcome.

Let me explain: when I was in middle and high school in the late '70s through to the mid-'80s, I helped my dad and friends recover wrecked aircraft for an insurance company. On one call, we had to go into a rather dense forest and recover a Bonanza, which flew VFR into IMC and slammed into a mountain. The coroner had already done his job, but nonetheless there were other things hanging around, such as blood, brain and feces, which are de rigueur in such an event of that magnitude...yet what drove it all home to a shocking degree were the other effects: twin toddler boys' things, such as broken car seat fragments, toys, diapers, you name it. That one broke me, I never helped on another recovery again. By that time, I had 8 years and several recoveries under my belt, including the 1983 midair collision of two Cessnas over Kent, by Seattle.

There are many things a pilot can control while flying, there are many more things (s)he is forced to come kindly to terms with...and also other things, based on mitigating circumstances, with which there is no negotiation whatsoever. When margins are cut far too close, throw a baby into the mix and what can end up a tragedy can be multiplied exponentially.

I keep wondering why the pilot didn't make an attempt at a roadway landing, as the highways appeared sparsely-occupied; even with occasional-yet-rare power lines, there is little else to interfere with such a forced landing, as it was open highway with few to no traffic controls or buildings. He opted for an open field covered in snow, which presents two realities: the smooth snow hides the irregularities of the land, plus said land probably has a degree of saturation due to moisture and a very rough, irregular surface after being turned over after harvest. All this proved true in this instance.

I'm glad nobody was seriously hurt, but I've witnessed fatalities for far less. But kids and aviation accidents make me cringe to no minor degree.

Sorry for the rant, but it hits far too close to home.
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Re: Carburettor Icing...

Postby Flacke » Fri Jun 23, 2017 2:27 am

Fozzer wrote:
It may seem strange, but even in my Flight Simulators, I automatically apply Carburettor Heat when reducing throttle settings prior to landing, and be ready to immediately cancel the setting to obtain maximum power if an abandoned landing and go-around is required,


:( ...!


Hi Fozzer, its fine to use carb heat in your Flight Sim as long as the airplane actually has a working carb heat knob. Its fun to fly right even on a Sim.
In real life and in the Sim the procedure is to apply carb heat when the engine is running at cruise power. This ensures enough heat to melt any ice quickly, then reduce power for the descent. If its a long descent or if carb icing conditions are an issue I like to keep the engine running at a heat-producing rpm and then clear the engine with carb heat occasionally during the descent.
Regarding water-injection, the big Hawker-Siddeley HS-748 Twin Turbine transport aircraft used Water-Methanol injection for maximum power on hot, high, or heavy takeoffs.
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