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Brown/Whiteout


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Set down quickly while you can see what is underneath you.  In my youthful career I've already gotten very close to a brownout and thankfully I just landed it very quickly without further result.  After we waited a while on the ground for the dust to settle we were prepared to leave I told my student this is the one time we wont dilly dally on the lift off.  We pulled pitch quite quickly and went directly into a takeoff roll inorder to avoid the brownout again on take off.  The whole situation was a very scary and stupid move on my behalf....live and learn.

 

 

PS this happened on an airport enviroment.  The airport in question only had three taxiways, one at each end and one in the middle.  I (in my infinite wisdom) decided it was a waste of time for my student to taxi all the way down to one of the taxiways and told him to just cross the innocent looking dirt...never again.

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Agree with jimbo. I have not much experience with brown-out but lots of experience with white-out conditions.

When wite-out conditions may be expexted the risk can be reduced by trying to blow the snow away with the rotor downwash and land with some forward speed. If you get in white-out conditions, lower the collective and land and keep the collective down until you regain visual references. Take-off in conditions where white-out conditions is expected should be performed as a max. performance take-off.

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I was in Mexico last year at a race and there was a 206 that was taking off.  As soon as the pilot pulled pitch the helicopter disappeared and he couldn't see a thing.  The helicopter was only about 3 feet off the ground and began forward flight.  He must have thought he was a little higher because he just passed a parked car by about 10 feet.  I could tell when he regained visibility because he immediately pulled pitch and climbed another 50 feet.  That was pretty scary for a few seconds.

Sorry this doesnt have to do much with your question, it just reminded me of that story.

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Never flown in snow but I regularly land in dusty/sandy areas. I will usually do a steep, slow approach and just let the helicopter go all the way to the ground without coming to a hover. If you set the power right you shouldn't have to pull in any pitch at the bottom. As soon as your skids touch ground continue lowering the collective.   On take off I try to climb vertically and move forward rather fast.  

 

I saw a video of a Cobra helicopter ,I believe in the first Gulf war trying to take off in the desert...You see the helicopter as it starts to pull pitch, it disappears in the dust, you can still hear it trying to fly out and then you see one of the rotor blades fly out of the dust cloud, after everything settles the helicopter is laying on its side and the crew is getting out.

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Some of my own advice on this stuff (let me know what else you all do):

 

WHITEOUT: If you can, land to an object that is in contrast with the snow (branch, rock...) If there is none try throwing something onto the snow when you fly by to give you a point to go to. Use the landing light to see how close you are to the snow, watch for uneven snow, realize you may sink up to your tail rotor, and don't hover too long if at all.

 

BROWNOUT: Make sure the ground you'll be going to is level. Pick a spot that you can still see something through the chin bubble, and keep an escape route if all goes to crap. Turn on the particle separator if you have one.

 

I also get my share of brownout landings (usually they are at night. The agencies have some great strobe lights that are good to use for reference (unless they put them under a tree!)).

 

I saw that cobra video. He was trying to do an ITO if I remember right. I think it would be very hard to take off in a brownout if you are heavily loaded.

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Can't speak for brownout but in the norwegian arctic, landing in recirculating snow was commonplace.  The technique was to aim for a zero/zero landing at a distinct marker.  That might be a branch, rock or your passenger (who, knowing what was required would kneel down in the snow with his back to you whilst you stuck the forward point of the right skid up his backside!).

If we were above the treeline with no other features we would drop a smoke grenade (which, if it works properly gives you a wind indication and a marker).

 

Whiteout more commonly occured above the treeline (often in Bowls /Cirques / corries) when the vis was hazy or in light snowfall.  It would be impossible to judge where the sky stopped and the surface began, lack of definition of the surface in those conditions made landing hazardous.  Best option there was to vacate the area pronto.

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Rey,

    Rudy had explained to me that if you encounter a white out that if you pick out something that you can land close to you can keep a visual of (like a flag if you have landed at this location before)that you have a clear visual of everything that is within the rotor diameter. The white out is on the outside of the rotor diameter, so you have a clear view of the ground close to the skids and directly under neath the helicopter. Also if possible land with a little forward airspeed (like a running landing) and that should help to prevent the white out conditon. The reason for this is because the snow is being blown behind the helicopter and not straight up in to the rotor. All this pertained to landings only, as for taking off get the helicopter light on the skids (you will encounter a little bit of a white out during this maneuver)but as soon as the helicopter gets light add a litte forward cyclic and when you start to move forward (look at your airspeed for verification of forward movement) pull in the power and you will clear the white out in a couple of feet. Just my two cents from what I was told. Thought that I would pass this on.

 

Steve

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From my experience in the Arctic, and winter in general, I get the machine light on the skids, then pull max power and perform a vertical takeoff.  Once above the "snowball", then I would transition to forward flight.   You only need to get to 50' or so to regain forward visibility, and then you can transistion to forward flight.   If you try to go forward immediately after lifting off, you may unknowingly sink the skids back into the snow, which might cause you to roll the a/c.  

 

 

Cheers

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  • 1 year later...

Everyone's posted some great techniques for brown/white-outs.  I hope this helps for brown-out discussion.  I'm not claiming to be a know-it-all, but am pretty good at describing things I've learned and seen:

 

I'm only a 500 hour UH-60L guy, but I do have have some experience with brown-outs in Iraq during OIF1.  I'm talking about no-joke brown-outs to LZ's with almost a foot of moon-dust (during OIF1 we didn't have as many hard-stand LZ's as there are now).

 

First, if you can do a run-on landing, do a run-on.  You can stay ahead of the dust cloud the whole way down.  Too easy and VERY safe.  Granted, terrain or your type of aircraft may not make this the best choice.

 

The next best thing you can do is take your doors off.  On our Hawks, we never saw the ground for any of our dust landings during the first 3 or so months in Iraq, but as soon as summer hit and we finally got the Army to approve us to fly doors off we lost pretty much all fear of dust landings as we could look straight down to our side and see the ground the ENTIRE way down (pretty huge shock after doing landings with the technique I'm about to mention).  The Blackhawk cockpit and doors hinder a good view directly below the aircraft (the chin bubble is more forward and allows you to view the dust being churned up right under the nose in front of you and you never really see ground through it in Iraqi dust).  Yes, doors off will make your entire cockpit dusty but it is SO worth the safety margin.  With doors off, it's a normal VMC steep approach.

 

For point landings, the adage I was taught in flight school and our unit taught before we got to Iraq that "you'll see the ground through the chin-bubble the whole way down" was completely untrue.  UH-60 and similar aircraft have too much air displacement under the rotor to stir up the super-fine dust that's here in Iraq.  We learned that if we were to go-around every time we lost the ground we would NEVER land to most non-hardened LZ's.  

 

Here's the technique I used and learned from multiple PIC's:  

 

1) Do a high recon of the LZ, obviously, and try to choose a bush, stake, rock, or something for a ground reference point to shoot for.  We didn't always have one... just make do.  Cardinal rule definitely applies for dust: land into the wind!

 

2) Key thing on a dust approach is the set-up.  On short final, stay just above effective translational lift, up around 100 feet or so on a nice long final, staying level until ready to commit to your steep approach (out of ground effect so as not to stir up too much dust).  

 

3) Slow your approach to a fast walk or enough to where as you descend you know you'll be able to plant the landing with little to no ground run (and still make a safe steep approach).  Take the time to get a good comfortable speed now BEFORE you reduce collective.

 

4) When you intercept the correct steep approach angle to your intended landing point, commit to a descent as "BDR" mentioned in his post with enough down collective to push through the ground effect at the bottom (firm enough to get you down QUICKLY through the dust while preventing any drift at the bottom).

 

5) Key thing is forward and down, forward and down.  If, as soon as you enter that descent you feel your approach will not be dead on straight ahead or you notice the slightest lateral drift; go around.  Take your time and do the set-up process again.  If you think your isn't fast enough to get you through the cushion at the bottom, then go-around and do the set-up again.

 

If the descent is quick enough you should only lose the ground about 10-15 feet up while feeling completely sure you will stick the landing with no drift and can brake hard for the landing and not roll but a few feet.  Remember, I'm talking about a Blackhawk here.

 

Key mitigating factors we used to help us:

1) Crewmember not on the controls focuses on the instruments and if sees an unusual attitude will announce "go- around," take the controls, and perform and instrument take-off (everything should be smooth and level the whole way down, so any deviation in attitude is clearly wrong- remember what I said about proper set-up).

2) Get your crewchiefs/medics to look out their windows to call dust for you ("at the tail, my door, your door, 10 feet, 5 feet") and be prepared that if they call out ANY drift you do an instant go-around.  We had this on occasion if we had a crewchief with Wiley-X goggles that was willing to keep his/her window open to call us down the whole way.  It was really effective for us, but we couldn't MAKE crewchiefs do it if they didn't have eye-protection.  We had plenty of eye injuries (yes, even with clear visors down) from the dust, dirt, straw, hay, etc. for the valiant ones trying to help us pilots get on the ground safely during those first few scary months.

3) ANYONE can call a go-around in a crew.  They may see something you're not (drift, obstacle, etc.).  Talk through all actions with your crew.  Go arounds are free.

 

For take-offs, I shouldn't say much as in the UH-60 "L" model Blackhawk with no wing/tanks we could pull power all day and never overtorque the aircraft.  We just did straight up, vertical instrument take-offs (ITO's) until clear of the dust cloud (50-80 feet), then transitioned to forward flight.  You guys in smaller aircraft might not have that luxury.

 

I hope this helps.  In short, a deliberate steep approach is all this is with a talk through of some key points to help make this easier and safer.  This is from 11 months of flying with MULTIPLE pilots in command and MANY lessons learned in how not to do it (from the invasion months when we had no clue how to do real dust landings in Iraq; I was co-pilot (read: along for the ride) for some of the scariest landings of my life during that time) to doing very accurate and safe formation flight dust landings (6 ships) at night under goggles by the end of our tour.  

 

Please don't sharp-shoot me specifically as I'm only stating what I saw and learned.  Please DO add any critical steps or clarification to any of the techniques I've mentioned (if you've had serious brown-out experience).

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I'm not going to sharp shoot you, thanks for the post. I have a question for you, how was the army dealing with the dust and sand getting into places it didn't belong, I would think that flying doors off in that enviorment would have made it heck for avonics. But then again all I fly are old Bell 206's, not to mention eye problems like you said.  The few  dusty landing I have made also had FD near, so I would ask for the Firemen to just wet down were I wanted to land. Works well, if you have people and things like fire trucks near by.  Thank you for your post  again and service to the nation.
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For the most part, we DIDN'T deal with the dust in the aircraft.  Most of the avionics held up REALLY well, though.  We did have issues with dust collecting on pitch links, uniballs, and the like.  Also, keyboard/number buttons like on our GPS would stick really bad.  

 

Consistent aircraft washings was a marginal help (not really because you can't hose down avionics bays- although that did help on main mast components), some units got a hold of clear flexible keyboard covers specifically made for our GPS to prevent buttons from sticking (like those 1980's dust covers they used to make for early computer keyboards).  I heard of some units just taking saran wrap and duct-taping a few layers over them (or a cut open freezer bag).  

 

I'll check with some buddies to see what they're doing now.  Unfortunately, I'm in a non-flying job for this tour (yes, another 1 year tour- hooray!).  Hence, why I have time to get on this forum:).

 

Yeah, water on the LZ before landing is a great short-term solution if you have FD assets available.  A couple of units tried out "gorilla snot" over here (it was a environmentally friendly super-glue type substance for dust) but it didn't last long.  Mobi-mats and thick plastic roll-able mats (really expensive types the air force had) were good, but both were expensive.  

 

A really good (and seemingly cheap) mat I saw was one our division used up north when we brought our Air Assault School instructors over.  They had a large, porous matt (like a thick tarp, but with tiny pores so the wind wouldn't catch it as bad) that was staked down (in a grid type pattern all over it).  I don't know where they got it, but it worked great.  We used it a lot for the repel portion of the course (where I went through the course with the first class that started, then got my repel qual and flew for subsequent classes).

 

Also, gravel has been our answer to most dust mitigation in Iraq.

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hawkdriver 101st

In your last post are you saying landing gravel was the way to go, I supose it was the least dangerous but what about shrapnell

(still supose in Iraque stone shrap is the least of your troubles)

only asking because have had a stones jam a flight colective linkage after landing on stones

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Good call- I should have clarified about the size of gravel.  Most of it in Iraq is really thick stuff (diameter of a tangerine to as big as a grapefruit- more or less "small rocks" as opposed to gravel) used especially to mitigate dust around a pad (although there were whole LZ's with this type of rock/gravel).  This was used where we had a metal pad (just big enough for the helicopter) with those rocks/gravel around the pad itself so you don't lose the pad on your approach.  We also used it along the edge of taxi-ways on airfields (where we would park), approaches to FARPs, etc.  

 

The smallest gravel I ever saw was no smaller than the diameter of a nickel.  In other words, stuff so big even a Blackhawk's rotor-wash didn't throw stuff (I can't speak for the Chinook guys though).  Now that I think of it, I rarely saw this smaller sized gravel, though (as most of our improved LZ's had to be UH-60 and CH-47 capable).  

 

Safety consideration: I guess look for gravel that's proportional to your sized aircraft for the given LZ.

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Great post fellow hawkdriver.

 

That is still the most prefered way for dust lands I teach today too.

 

Ive seen all kinds of dust from Afghanistan to Iraq and lots of snow in Korea which is a little different.

 

Like stated above, at least for our airframe staying OGE or about 75 or so feet till I intercept a steeper then normal approach angle and maintain a low power approach at the high end of ETL to to the ground is the way to go.

 

We didnt go doors off in either theater and it works the same. At ETL and above I can keep the dust at my transistion section so it's predictable when it is actually going to catch up with me at landing. With that said, foward rolling landing is the best, but executing that technique to a point works out just as fine.

 

Additionally landing in the wind is great, but sometimes if you are multiship landing in a quartering or crosswind is even better when you have the power available and ability to do so due to that actual area to land in.

 

We also had inches of dust in the cockpit. Price of doing bizz. Nothing a paintbrush cant take care of later on for the most part.

 

We did start getting this stuff called elephant snot that was like black tar that hardened. It works out pretty good to keep the dust down, but breaks up in a short time.

 

Great discussion on techniques that save lives.

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  • 2 years later...

The best technique by far is don't do it. If you have any choice at all, and you almost always have a choice as a civilian, don't land in brownout conditions. As soon as you see that you may encounter it, pull maximum power and start a climb, and climb out of it. Once you're inside the dust, and can't see outside, you have no idea whether you're moving sideways, forward, bacward, up or down. You're screwed. You're very likely to roll it up in a ball. I once had a fire dept set up an LZ at night in a silica plant, which produced dust as a product, and it was everywhere inside the plant. I saw the dustball coming at 100' or so, and started a max climb at 100% torque, and still got inside it briefly, although I was climbing out. If I had continued into that, the end results would not have been pretty. IMO you need to be ready for brownout or whiteout conditions, and start an immediate climb as soon as you even suspect that it's going to happen. Landing in those conditions is as unsafe as anything you can do, or even contemplate. You wouldn't try to land in dense fog, would you, and trying it in sand or snow is even more dangerous.

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  • 2 years later...

When doing a brownout/whiteout landing many of you seem to suggest to look for visual references on the ground. I am researching a new systems which uses an acoustic reference. There are three different possibilities, using an acoustic vector sensor (AVS), which is very small and is able to determine direction of the sound source.

 

1) Ground based acoustic detection to home in the helicopter

At a given landing area, AVS can be installed. Considering the helicopter as a single tonal sound source, the position of the helicopter (bearing, elevation, and range) can be determined and relayed to the pilot.

 

2) Airborne AVS detecting acoustic ground beacon

AVS can detect a beacon on the ground, despite the tonal background noise of the helicopter and the wind noise around the sensor

 

3) Helicopter's own low frequency noise transmission is used

If the helicopter is seen as a noise source, its reflection on the ground can be used to aid navigation. Approaching the ground, acoustic reflection takes place, causing standing waves to occur. Exploiting this phenomenon, the helicopter can navigate in a similar fashion to a bat.

 

What do you experienced guys think. Could this be of any help while landing in DVE?

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  • 3 years later...

 

For a newbie please- would somebody define a brownout and a white out.

Thanks alot

Chris

 

So, what's a BLUE-OUT?

 

:o

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