Robinson R44 air filter problem, total engine failure, autorotation landing
Thread Starter
Join Date: Nov 2008
Location: Czech republic
Age: 48
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
Robinson R44 air filter problem, total engine failure, autorotation landing
Hi guys,
My first real autorotation landing with passengers
Without passenger injuries or damage of the helicopter.
The helicopter (Robinson R44 Astro) began to gently vibrate after 10 min of flight at a height of 200m AGL. During the next 50 seconds the engine lost the power and I made an autorotation landing (2 pax on board).
The problem was in WIX air filter. The quality of rubber is really poor :-(
After replacing the air filter I was able to continue in flying.
Bena
My first real autorotation landing with passengers
Without passenger injuries or damage of the helicopter. The helicopter (Robinson R44 Astro) began to gently vibrate after 10 min of flight at a height of 200m AGL. During the next 50 seconds the engine lost the power and I made an autorotation landing (2 pax on board).
The problem was in WIX air filter. The quality of rubber is really poor :-(
After replacing the air filter I was able to continue in flying.
Bena
Thread Starter
Join Date: Nov 2008
Location: Czech republic
Age: 48
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
Genuine filter
The main problem is that this piece is delivered originally from Robinson helicopter company. The machine was after 100 hour inspection.
Last edited by bena; 20th Jul 2012 at 05:53.
Join Date: Aug 2007
Location: USA
Posts: 278
Likes: 0
Received 0 Likes
on
0 Posts
I'm with Soave Pilot on this one.
I Googled what I think might be the part number stamped on the filter: WIX 42097 ... and I get a page for an automobile filter:
WIX 42097 - Air Filter | O'Reilly Auto Parts
A call to both Robinson and your 100 hour inspector seems in order.
I Googled what I think might be the part number stamped on the filter: WIX 42097 ... and I get a page for an automobile filter:
WIX 42097 - Air Filter | O'Reilly Auto Parts
A call to both Robinson and your 100 hour inspector seems in order.
Join Date: Jan 2009
Location: Far North Queensland
Age: 37
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
Good job on the auto but I can't see how a filter in that condition could limit your power that much.
Unless there was something else that isn't shown, it'd be a brave man who flies a machine away after autoing it to the ground and changing JUST the air filter.
All Robinson do is inspect the automotive filter and put their own sticker on it which has a part number and batch number and charge ten times the price for it.
You don't honestly think Wix has an aviation division?
Unless there was something else that isn't shown, it'd be a brave man who flies a machine away after autoing it to the ground and changing JUST the air filter.
All Robinson do is inspect the automotive filter and put their own sticker on it which has a part number and batch number and charge ten times the price for it.
You don't honestly think Wix has an aviation division?
Join Date: Jun 2008
Location: England & Scotland
Age: 63
Posts: 1,413
Likes: 0
Received 0 Likes
on
0 Posts
If there is a risk that someone might have put a random automobile filter into an aircraft engine and released it to flight .....
I suppose the critical question is how many cubif feet / min flow through the filter, and if this is not the "correct" item, how many cubic feet / min does the engine need?
I suppose the critical question is how many cubif feet / min flow through the filter, and if this is not the "correct" item, how many cubic feet / min does the engine need?
Last edited by John R81; 20th Jul 2012 at 15:27.
Join Date: Jan 2009
Location: Far North Queensland
Age: 37
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
Don't get your knickers in a knot boys. Remember, Robinson make a very cheap helicopter and they do it by using cheap, readily available parts.
Like I said, all they do is buy a container load of Wix air filters, open and inspect them all (well, they say they do, I'm guessing they inspect every tenth one) and then put their part number sticker on it and sell it for ten times the price.
I stand by my original post.
From a filter I fitted today.
Like I said, all they do is buy a container load of Wix air filters, open and inspect them all (well, they say they do, I'm guessing they inspect every tenth one) and then put their part number sticker on it and sell it for ten times the price.
I stand by my original post.
From a filter I fitted today.
Join Date: May 2011
Location: you aint seen me rite
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
You sure it wasn't carb icing? I've seen the orange edged type filters completely deformed and melted without causing an engine failure. RHC stopped using this type a few years ago.
I would suggest that the long tail of rubber has been drawn in to the carburretor venturi and has been flapping around in the airflow.
That would give you a disrupted airflow and a loss of power.
Saw something similar on a Cessna 152 that ingested a piece of baffle rubber.
Cause I would suggest is that on installation the filter has been forced over a lip at an angle guillotining the rubber edge.
No fault of the filter.
That would give you a disrupted airflow and a loss of power.
Saw something similar on a Cessna 152 that ingested a piece of baffle rubber.
Cause I would suggest is that on installation the filter has been forced over a lip at an angle guillotining the rubber edge.
No fault of the filter.
Last edited by ericferret; 21st Jul 2012 at 18:06.
Thread Starter
Join Date: Nov 2008
Location: Czech republic
Age: 48
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
Good job Matari with the information of auto filter :-)
The rubber is fragile than the normal and it wasn't problem only this one piece. So if you can check it , do it. You can simply crook the rubber and if some part crumble, you are in a trouble. If is the steel grid partly visible on a rubber edge of a filter than is this one bad too.
I agree with ericferret. The engine speed go down slowly. When the mechanic execute the inspection, he found the long part in carburetor venturi and detached part of rubber was washed-up.
To IMO, I'm sure that it wasn't carb icing. The temperature was 20-25 deg Celsia and I pull full the carb heat.
The rubber is fragile than the normal and it wasn't problem only this one piece. So if you can check it , do it. You can simply crook the rubber and if some part crumble, you are in a trouble. If is the steel grid partly visible on a rubber edge of a filter than is this one bad too.
I agree with ericferret. The engine speed go down slowly. When the mechanic execute the inspection, he found the long part in carburetor venturi and detached part of rubber was washed-up.
To IMO, I'm sure that it wasn't carb icing. The temperature was 20-25 deg Celsia and I pull full the carb heat.
Last edited by bena; 21st Jul 2012 at 21:21.
Join Date: Oct 2003
Location: Canada
Posts: 1,852
Likes: 0
Received 0 Likes
on
0 Posts
A number of years ago a carbureted plane - I think it was a Cessna 140 - had an engine failure and made a forced landing on a beach near Toronto when it was 85 deg F. or about 30 C. When the engineers pulled the air filter they found water in the carburetor and determined the failure was caused by carb icing. It was quite humid that day and this was obviously the major factor in this case. I heard this directly from the owner of the plane who had a large flight school at YTZ.
Join Date: Feb 2005
Location: Australia
Posts: 1,957
Likes: 0
Received 0 Likes
on
0 Posts
found water in the carburetor and determined the failure was caused by carb icing
how much air? there's 540 cubes turning at about 2700 RPM from memory.
being an astro icing maybe a possibility, and the tail of rubber or bits broken off may also have fouled the crucial bit where fuel jets in. I think I would like to look at a picture of the venturi area before jumping to conclusions though.
Wake up folks.
FAA "Certified" or "Approved" means that it meets their minimum requirement. Quality, reliability or durability is not guaranteed.
2 ways to build a helicopter.
1/ To meet the basic design requirement. i.e. regulations.
2/ Build a helicopter that is safe and reliable, then durable and by design far exceeds the minimum requirements.
Remember from the IT guys - Cheaper, Faster, Better - pick 2.
FAA "Certified" or "Approved" means that it meets their minimum requirement. Quality, reliability or durability is not guaranteed.
2 ways to build a helicopter.
1/ To meet the basic design requirement. i.e. regulations.
2/ Build a helicopter that is safe and reliable, then durable and by design far exceeds the minimum requirements.
Remember from the IT guys - Cheaper, Faster, Better - pick 2.
Join Date: Oct 2003
Location: Canada
Posts: 1,852
Likes: 0
Received 0 Likes
on
0 Posts
ahhh, would you like to think about that for a bit? I think you will conclude that it is patent nonsense.
Join Date: Jan 2008
Location: lancs.UK
Age: 77
Posts: 1,191
Likes: 0
Received 0 Likes
on
0 Posts
I think TET was referring to the R44, not the cessna.
I'd agree withthe others- careless installation has pulled a shred off which was disturbing venturi airflow.
SU carbs on cars were deemed to have "needle-flutter" caused by airflow when the venturi was wide- this caused unstable mixture and prevented the carb. from meeting emergent emission standards. the "cure" was to spring-bias the needle so that it always pressed against the jet,thus stabilising it....a flawed fix, 'cos the constant "sawing" up and down ensured both jet and needle wore rapidly.....not so bad on wide venturi openings, but a bugger when the needle was fully down and the wear had a dramatic effect on the size of the gap twixt needle and jet.
I digress (as usual
) the shred of rubber would not only thrash around wildly, but would also elongate considerably, as this foam has a considerable amount of elasticity as one of it's basic functions.
Earlier posters are bang-on.....careless installation. and, yes, they're quite likely bog-standard automotive parts probably same with oil and fuel filters. anyone thinking otherwise hasn't a clue about development and tooling costs.....the huge markup increases the distributor's profit and gives enough extra to also pay the premium for product-liability insurance.- Cynic? moi?
I'd agree withthe others- careless installation has pulled a shred off which was disturbing venturi airflow.
SU carbs on cars were deemed to have "needle-flutter" caused by airflow when the venturi was wide- this caused unstable mixture and prevented the carb. from meeting emergent emission standards. the "cure" was to spring-bias the needle so that it always pressed against the jet,thus stabilising it....a flawed fix, 'cos the constant "sawing" up and down ensured both jet and needle wore rapidly.....not so bad on wide venturi openings, but a bugger when the needle was fully down and the wear had a dramatic effect on the size of the gap twixt needle and jet.
I digress (as usual
) the shred of rubber would not only thrash around wildly, but would also elongate considerably, as this foam has a considerable amount of elasticity as one of it's basic functions.Earlier posters are bang-on.....careless installation. and, yes, they're quite likely bog-standard automotive parts probably same with oil and fuel filters. anyone thinking otherwise hasn't a clue about development and tooling costs.....the huge markup increases the distributor's profit and gives enough extra to also pay the premium for product-liability insurance.- Cynic? moi?
Join Date: Feb 2005
Location: Australia
Posts: 1,957
Likes: 0
Received 0 Likes
on
0 Posts
found water in the carburetor and determined the failure was caused by carb icing
Water inside the carburettor comes from dirty fuel and overloaded filters and almost always causes the engine to stop because the blessed stuff will not vapourise the way fuel does when the airflow thru the venturi is trying to suck it out of the carby bowl to mix with air and form a combustable mixture. If it does get sucked out of course it would destroy the usual ratio of the mixture of fuel to air that is necesssary for combustion.
The term Carby ice on the other hand refers to and is caused by too much water vapour in the atmosphere at the prevailing temperature when it is being drawn thru the venturi where the fuel air mixing takes place, ice will build up and restrict the flow of air and the engine will usually splutter first then can quite quickly stop.
Helicopter engines will become silent, and an auto is required, especially if the machine is at a low level. Usually an aeroplane engine can easily be restarted because the propellor should be windmilling and there is often a much slower descent rate in engine off mode.
I suggest the engineer may have been having a serious lend of the pilot concerned, carby ice from water in the carburettor, indeed! Made my day.
cheers tet
But if the venturi blocks due to icing, the engine stops and later the carb is inspected, the ice will have melted and left water in the carb - I think that is what rotornut was getting at.