It's smoke season

[NoBShere]

So work has been busy lately and I haven't been flying in about a month. Yesterday I found myself with some free time and the RG was available so let's go poke some holes in the sky and knock out some landings. I took off from RHV (San Jose) and went to E16 (San Martin). On my way out of RHV i noticed some haze but, that is typical this time of year. On my way back to RHV about an hour later, normal stuff, get the weather, contact tower. Around 10 or 15 miles out I had noticed that the haze appeared "thicker". I quickly checked the weather again and visibility was reported at 10 miles and clouds were scattered way above my altitude. I thought Ok, just normal haze no big deal. on my way in, tower advises of an aircraft departing the pattern of my location and the pilot responds that the smoke is thick and he can't see me. When tower advises me of the other aircraft, I respond similarly. Then immediately someone else contacts tower to talk about the smoke. Right about this time, I think i should let them know I can't see the field. Unfortunately, the smoke conversation that tower is having is taking longer than expected but, its providing me with some useful information. I keyed the mic a couple times, hoping they might wrap up so I can talk. Just as they do stop talking, field comes into sight and I am not lined as well as i would have liked but, easily corrected for an uneventful landing.

Part of me says I should have told tower a little earlier about visibility but, it was changing quickly as there was brush fire just north of the field that started after I departed RHV. I didn't know about the brush fire until after I landed. The whole time I thought it was just smoke that had blown in from far away, which can happen. Additionally, with the hills to the east and smaller hill to the south, it appeared the smoke just wasn't blowing out and I may have come through the worst of it. For instance, the tower is on the west side of the field and it was clear there.

As i rolled onto the taxi way, I was reminded of a night flight a few years ago while returning from dinner. Due to the street lights and businesses in the area, I found myself doubting if i was lined up for 31R properly. Just as I started to contact tower to discuss, it became clear I was lined properly. Shortly after that, my nephew was in town and we went on tower tour. I was telling the controller about my questioning of where the runway vs road was on that night flight. Her response was that I'm not the only one and just let us know and we will help you out. My learning from this was just speak up earlier but, I'm not going to beat myself up for thinking through a situation. And a reminder that smoke can behave differently from clouds and fog.

 

[GeorgeC]

I added this to my preflight routine recently:
http://www.ospo.noaa.gov/data/spl/kmlfiles/fire/smoke.kmz

Previous discussion https://www.pilotsofamerica.com/community/threads/new-ticket.133086/#post-3115924

 

[sourdough44]

I was flying the Al-Can Hwy, back in the 90’s. Once north of the border, we’ll north in Canada, smoke was a major factor. I was able to fly above the worst of it. I did hear some planes turning around over smoke visibility. It can be a real impediment to flight.

 

[DesertNomad]

Also be aware that the ASOS/AWOS equipment is not very good at figuring out visibility in smoke. It will usually be much worse than reported.

 

[geezer]

The smoke plume close to a major fire may be oxygen depleted, resulting in a major decrease of power. If the wildfire consumed half the oxygen, you will have a maximum of 50% power possible, and a wildly over rich mixture.

Further from the scene, the percentage of O2 converted to CO2 will be less, but the reduction combined with the mixture going over rich can cause a surprising reduction of actual power without an obvious cause.

Approaching a mountain pass, or in an IFR approach to land, even a moderate reduction can be deadly. Smoke has much more than a visibility risk.

 

[NoBShere]

Also be aware that the ASOS/AWOS equipment is not very good at figuring out visibility in smoke. It will usually be much worse than reported.

I was going to ask if anyone could comment on this. I was curious if that was case or if it was more to due with how variable smoke can be. Probably both?

 

[GeorgeC]

All of the stations near me were reporting CAVU when the visibility from the smoke was pretty lousy.

 

[eman1200]

e v e r y season is smoke season, ya dig? ya feel me?

 

[murphey]

In a eastern 'burb of Denver, less than 20 miles from the mountains, I can't even see the outline of the hills. Been this way for a few weeks. I did 3 Young Eagle flights earlier this week. Nothin'. No Longs Peak, no Pike Peak (ok, that's 70 miles away) but not even Mt Evans or the foothills. Hoping the forecast monsoons this weekend will clear the area for a bit, but not depending on it.

 

[Lachlan]

I can normally see forever, the air is usually crystal clear. I couldn’t clearly see 5 miles. This was 7/24/21 in the Adirondack of northern NY state.

 

[brcase]

Way better than Central Idaho last Friday, Smoke coming from California and Oregon as the Idaho fires were all well North here.

 

[Zeldman]

Smoke can be relentless, so much more so than fog. I got a face full of smoke once when flying and had to physically hold an eye open to see the instruments. When that eye was so blurred that I could not see then I would let that one close and hold the other open.

 

[flyingron]

Coming into OSH two weeks ago I was certainly glad I had an instrument rating. While I didn't actually get an IFR clearance (it was 4SM reported), it wasn't comfortable visual flying.

 

[Ed Haywood]

It's also Sahara dust storm season in the Southeast.