Saharan Dust Plume

[rocketman]

With the Saharan dust plume coming soon to the southern parts of the USA, does anyone have any knowledge on how this might effect our airplanes with respect to the very small dust particles getting through the air filters and into the engine. There is very little information on this subject I could find. AOPA had no knowledge when I called them today. I understand these dust particles travel anywhere between 5,000 to 20,000 feet. and are as small as a couple of microns in diameter. Although this is a yearly event for this plume, this year the Saharan is much thicker and intense then in the past. 

[tmo]

When a volcano last decided to have a party it was jet CAT that had issues, not piston GA. Not sure how similar sand dust is to volcanic dust, but the volcanic dust can be dangerous.

[Nick Pilotte]

This sounds similar to the powder like sand at the Playa where Burning Man is held.  Perhaps @gsxrpilot can comment.  He’s BTDT.  

[RLCarter]

Living on the third coast (Gulf of Mexico) we see the dust storms migrate across the pond every year, some years are worse than others, we also get the smoke from Mexico, same thing. They also burn sugar cane down here and I’ve seen ash as high as 7500 ft. 

[carusoam]

Based on the prior experience of the Saharan sand and volcanic clouds...

The sand particles are dangerous for our engines...

larger ones get removed by the air and oil filters...

If you fly through a cloud of ultra fine sand... it would be measurable in the oil analysis SiO2

The weather bureaus should be able to advise where the clouds are in a useable format...

We have a weather guy around here we can ask...

1) try to avoid it

2) If you end up in it, leave it...

3) Change the oil, test the oil as you normally would... but don’t wait for the regular time between oil changes...

Essentially, getting sand in your oil is a high wear issue... With turbines, that is a build up and tight tolerance problem for unfiltered air in the jet engine... jets can experience a flame-out at high altitudes...

PP thoughts only, based on old fuzzy memories...

Best regards,

-a-

[Seth]

Evidently this happens nearly every year or every few years. This one is just being reported on. It may also be larger than normal, but that is speculation on my part. I too am worried about operating in it.

Good job bringing this topic up for discussion.

-Seth

[gsxrpilot]

2 hours ago, Nick Pilotte said:

This sounds similar to the powder like sand at the Playa where Burning Man is held.  Perhaps @gsxrpilot can comment.  He’s BTDT.  

The powder that is the Playa in northern Nevada where Burning Man is held each year, is so fine that taking a bite of food that is dusted, is imperceptible to your mouth. It's finer than talcum powder. I've been to BM two times in my Mooney and both times made multiple flights in and out. Landing on the playa every time. Each time after returning, I had SWTA do a full service that opened everything up and changed every possible filter on the plane and washed everything down with appropriate solvents. We never found any problems and the filters were never even really dirty. 

Based on that experience, I wouldn't worry about this years Sahara dust.

[0TreeLemur]

It's here.  GOES true color image shows the Saharan dust cloud has reached the gulf coast.   I wouldn't fly through it unless I had to.  The filter won't catch these particles.   The risk is to the most expensive part of our aircraft.  Our engines ingest almost  1000 lb of air per hour.   Add a teaspoon of dust passing through the filter each hour.  If you are ok with that, have fun flying.  Numerical simulations call for it to move north over the southeast then back out to the east over the mid-Atlantic region over the next few days.  There is another dust cloud behind this one, not sure it will make it to CONUS.

 

[gsxrpilot]

If the particles are so small/fine that they pass right through any filter... I don't see them doing any damage to the engine.

[carusoam]

Expect the sand cloud to follow the typical route that Hurricanes do...

They start over the Sahara going West...

Proceed towards the Caribbean before heading North...

Then north along the Mississippi until getting pushed back out to sea... by our prevailing West to East winds...

So expect waves of sand clouds... rainy weather probably has a good way of getting the sand to fall out of solution...

 

Seeing if @Scott Dennstaedt is around for a weather comment...
 

PP thoughts only, not a weather guy...

Best regards,

-a-

[GDGR]

Power Boost  - CLOSED

[GeeBee]

Going to create some really fine St. Elmo's.

 

 

[EricJ]

I live in the southwest.    Dust is a way of life.   Dust is normal.   Do not fear the dust.

 

[jaylw314]

IIRC, sand in the Sahara is notable for having very round particles from being blown around all the time, unlike volcanic ash which is usually made of jagged particles from fractured glass.  OTOH, I'm guessing stuff that is small enough to be blow halfway across the world is probably too small to be abrasive anyway.  Fun fact, the dust from the Sahara is part of what makes the soil in the Midwest so fertile, so give thanks to the dust storms

 

[EricJ]

Haboob.   We get these a few times a year during our summer "monsoon" season.

 

[Davidv]

Thanks for posting this as well.  I'm flying from Boston to FXE later today and any PIREPS from those who have flown through it on how high the top is or severity would be appreciated...

[rbridges]

On 6/24/2020 at 8:32 PM, jaylw314 said:

Fun fact, the dust from the Sahara is part of what makes the soil in the Midwest so fertile, so give thanks to the dust storms

 

I heard that elsewhere. Doesn't make sense to me, but interesting tidbit. 

[N201MKTurbo]

1 hour ago, Davidv said:

Thanks for posting this as well.  I'm flying from Boston to FXE later today and any PIREPS from those who have flown through it on how high the top is or severity would be appreciated...

I used to commute from Phoenix to Tucson. Did it for 20 years with the Mooney. During the Monsoon season I had to deal with them almost every day.

The dust storms radiate out from thunderstorm cells. You can see them on radar sometimes. The tops are around 4000 feet.

They look like death on wheels, but the worst part is the reduced visibility.

I would never fly into one, but two different times I was flying home and the vis just kept getting worse and worse. In both cases I thought "if it gets much worse I'll have to turn around". All of a sudden, Clear skies! I had flown from the inside through the dust wall.

Surprisingly, they aren't very bumpy.

[ArtVandelay]

Thanks for posting this as well.  I'm flying from Boston to FXE later today and any PIREPS from those who have flown through it on how high the top is or severity would be appreciated...

As of 5:00am the southeast Florida skies were clear, I could see stars clearly. I predict it will be a non issue. Thunderstorms on the other hand....

[Hank]

1 hour ago, N201MKTurbo said:

I used to commute from Phoenix to Tucson. Did it for 20 years with the Mooney. During the Monsoon season I had to deal with them almost every day.

The dust storms radiate out from thunderstorm cells. You can see them on radar sometimes. The tops are around 4000 feet.

They look like death on wheels, but the worst part is the reduced visibility.

I would never fly into one, but two different times I was flying home and the vis just kept getting worse and worse. In both cases I thought "if it gets much worse I'll have to turn around". All of a sudden, Clear skies! I had flown from the inside through the dust wall.

Surprisingly, they aren't very bumpy.

SW duststorms are a different phenomenon than what brings Saharan dust across the Atlantic. 

[1001001]

On 6/24/2020 at 6:26 PM, carusoam said:

. rainy weather probably has a good way of getting the sand to fall out of solution...

I would not count on that.  In wet particulate scrubbers that are specifically designed to remove dust and ash, the difficulty of removing particulate increases exponentially as the size of the individual particles is reduced.  Rain is not enough to knock the fine stuff down, especially in an open environment with large liquid droplets and a large mean free path between droplets. 

[Hank]

2 minutes ago, 1001001 said:

I would not count on that.  In wet particulate scrubbers that are specifically designed to remove dust and ash, the difficulty of removing particulate increases exponentially as the size of the individual particles is reduced.  Rain is not enough to knock the fine stuff down, especially in an open environment with large liquid droplets and a large mean free path between droplets. 

True dat! My senior project in college examined removing particulate from smokestacks in various spray patterns and airflow rates. T'ain't as easy as it sounds . . . .

[EricJ]

1 hour ago, Hank said:

SW duststorms are a different phenomenon than what brings Saharan dust across the Atlantic. 

For flying, though, the effect of having a lot of dust suspended in the air is similar.    I think if people keep their air filters clean and don't use their ram-air (if equipped) their airplane will likely be fine.

[1001001]

52 minutes ago, EricJ said:

For flying, though, the effect of having a lot of dust suspended in the air is similar.    I think if people keep their air filters clean and don't use their ram-air (if equipped) their airplane will likely be fine.

What kind of particle size are we talking about?  I have a feeling that a pleated or oiled sponge induction air filter is likely not going to do much to such a fine dust as is described above.  HEPA filters are generally rated to stop particles above 0.3 micron in size, but in general I can't even find references for the capabilities of typical induction air filters.  Fine dust may simply pass through the filters and not even foul them.

[gsxrpilot]

13 minutes ago, 1001001 said:

Fine dust may simply pass through the filters and not even foul them.

It will also then, pass through your cylinders without any effect on them either.