Dense haze

Old Geek

Old Geek

Pattern Altitude
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Old Geek
After Christmas dinner, I drove the son-in-law out to the airport for a little sightseeing flight. The AWOS was reporting 6 miles vis, no clouds and no wind. We've been in the middle of a long period of inversion haze here and things didn't look too bad on the ground. We went up with the plan of climbing above the haze and looking around. At 2000', the haze was so dense that I became concerned about being able to spot traffic. I was within 4 miles of three uncontrolled fields and was becoming distinctly uncomfortable. I still had the ground and the horizon in sight, but it seemed unlikely that I had 3 miles of forward visibility. We went back down to 1000' where the vis was at least 3 miles and puttered around for awhile and then did some takeoffs and landings.

Anyone else have to deal with this before?
 
I was guessing inversion, and I saw you mentioned it when I read your post again..

It happens, I saw it once out East. I think the LA basin is subject to inversions too?
 
Northern California weather is odd lately. I drove all the way to the airport yesterday and had to decide not to go up. The briefer told me I had no worries but by the time I got there the airport was starting to get a ceiling at / below TPA already. Driving up there we saw a lot of haze, fog, clouds, etc. I was really bummed, and called the phone AWOS every thirty minutes after we left. Sure enough, a few hours later, the clouds were even lower. I made the right choice but it sucked.
 
We used to get that in late summer in Iowa. It was like flying inside a ping pong ball, with visibility down -- and not much more.

Add a setting sun to the mix, diffracting off the haze, and it's pretty much IFR.
 
I've had that happen to me before. You can be legal VFR, and lose your horizon if you have sufficient altitude. Not a good situation to be in if your instrument skills are rusty.
 
Sac Arrow said:
I've had that happen to me before. You can be legal VFR, and lose your horizon if you have sufficient altitude. Not a good situation to be in if your instrument skills are rusty.
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Say What???
 
It is hazy like that around Memphis, but usually not as bad as you describe. When I fly VFR much in weather like that, the eyes really start getting tired of straining to see out into the murk. Not a lot of fun.
 
That exactly. The thing about haze is that there is usually a low enough ceiling to it that you fly out of it in to clear air before you lose sight of the ground straight out the window. Otherwise, imagine being at 10,000 feet in 3 mile visibility. Draw a cone starting from the bottom of your airplane extending to the ground so that the slant length is three miles. The ground, if you can see it at all, is like a small furry ball below you. Kind of like flying on a clear, moonless night over an unlit area. You can see stars and traffic, but no horizon. A star above you or a circular ground patch under you doesn't give you a real attitude reference.
 
Then I think we need a new definition of VMC. We'll call it FVMC for Flying VMC. This is where you can see enough that you don't care if you lose your instruments and can continue the flight safely.
 
Jaybird180 said:
Then I think we need a new definition of VMC. We'll call it FVMC for Flying VMC. This is where you can see enough that you don't care if you lose your instruments and can continue the flight safely.
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And Old Geek did exactly the right thing. Decending is always a good option, particularly if you're over flat land. But it isn't aways a case of climbing in to a known haze layer. I've been happily cruising at 7,000 feet on a long flight in clear air, and found visibility to gradually decrease to a point where the horizon disappears. It's not like a cloud, where you can see it and avoid it before you're in it. What would I do if I were on a VFR flight and ran in to those conditions? Highly dependent on the situation. Decending is a good option, but if I'm reasonably certain I was "legal" (I can see other traffic, patches of ground) I would hold my altitude and treat it as any other flight in IMC and decend closer to my destination. If I was in terrain, I'd climb to a known safe altitude and head toward some flat land. If I couldn't do that, I'd turn back. Otherwise, I'd file and continue the flight IFR.

It's sort of a moot issue to me personally as the few times I've run in to those conditions, I was already on an IFR flight plan.
 
I had this happen at 5500 feet VFR over SC this summer. It was one of those days where it really wanted to be 95F but it just wouldn't warm up. Vis kept getting shorter and shorter, as a fresh PPL it finally got uncomfortable (but still very legal) and I turned around and descended. Ended up landing to wait out warmer temps and going later, but had to stay under a layer that was at about 3000. What was odd was that at one point it started getting bad again (but again still very legal) and I was getting an AWOS about 12 miles ahead calling for CAVU. Sure enough, as I got about 5 miles from that airport it all went away...maybe coastal winds...?

Sac Arrow said:
And Old Geek did exactly the right thing. Decending is always a good option, particularly if you're over flat land. But it isn't aways a case of climbing in to a known haze layer. I've been happily cruising at 7,000 feet on a long flight in clear air, and found visibility to gradually decrease to a point where the horizon disappears. It's not like a cloud, where you can see it and avoid it before you're in it. What would I do if I were on a VFR flight and ran in to those conditions? Highly dependent on the situation. Decending is a good option, but if I'm reasonably certain I was "legal" (I can see other traffic, patches of ground) I would hold my altitude and treat it as any other flight in IMC and decend closer to my destination. If I was in terrain, I'd climb to a known safe altitude and head toward some flat land. If I couldn't do that, I'd turn back. Otherwise, I'd file and continue the flight IFR.

It's sort of a moot issue to me personally as the few times I've run in to those conditions, I was already on an IFR flight plan.
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I remember not feeling very VFR in the early 90s smog over L.A., flying out of KVNY.

Denver's wintertime temperature inversions can also trap particulates and smog below the inversion and make visibility cruddy at that altitude but it's rare that gets very thick/bad anymore.

When I was a kid you could go up to the foothills near Golden and not be able to see Downtown Denver. Stapleton used to be under that crud. DIA is too far out of the bowl.
 
gtmule said:
I had this happen at 5500 feet VFR over SC this summer. It was one of those days where it really wanted to be 95F but it just wouldn't warm up. Vis kept getting shorter and shorter, as a fresh PPL it finally got uncomfortable (but still very legal) and I turned around and descended. Ended up landing to wait out warmer temps and going later, but had to stay under a layer that was at about 3000. What was odd was that at one point it started getting bad again (but again still very legal) and I was getting an AWOS about 12 miles ahead calling for CAVU. Sure enough, as I got about 5 miles from that airport it all went away...maybe coastal winds...?
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You probably learned that 5500' over SC is pointless unless your avoiding turbulence or heat.
 
dmccormack said:
You probably learned that 5500' over SC is pointless unless your avoiding turbulence or heat.
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I was attempting to avoid both. Felt like the DP was 85, and it was 85... I wasn't really THAT bumpy, but it was the wife's first trip so I wanted to keep it as smooth as possible.
 
gtmule said:
I was attempting to avoid both. Felt like the DP was 85, and it was 85... I wasn't really THAT bumpy, but it was the wife's first trip so I wanted to keep it as smooth as possible.
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You may want to consider leaving early in the AM.

With nervous pax I plan o-dark-thirty departures. It's calmer, they tend to fall asleep at altitude, and everyone is happier.

:yesnod:
 
denverpilot said:
I remember not feeling very VFR in the early 90s smog over L.A., flying out of KVNY.

Denver's wintertime temperature inversions can also trap particulates and smog below the inversion and make visibility cruddy at that altitude but it's rare that gets very thick/bad anymore.

When I was a kid you could go up to the foothills near Golden and not be able to see Downtown Denver. Stapleton used to be under that crud. DIA is too far out of the bowl.
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I remember the brown cloud from when we lived there 30 years ago. Good viz where we lived SW of Denver, but when you looked towards the city the cloud was very obvious.
 
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