Haze during night flight?

[woodstock]

how much haze would you consider acceptable for a night flight? little/none? do you go by the posted Viz limits (i.e. 6-plus, etc.) or does the indication of any haze throw that out?

 

[Michael]

depends on if your instrument rated or not, and where the flight would take place. Over the water or desert forgetaboutit (vfr). over a congested city where you could make out the lights and horizon, i would think about it.

 

[woodstock]

this would be my regular training flight - JYO to MRB or the like.

 

[Dave Krall CFII]

how much haze would you consider acceptable for a night flight? little/none? do you go by the posted Viz limits (i.e. 6-plus, etc.) or does the indication of any haze throw that out?

Watch out for the "illusion of haze" illusion too, especially when landing.

 

[jdwatson]

Watch out for the "illusion of haze" illusion too, especially when landing.

What is the illusion of haze illusion ?

 

[Dave Siciliano]

Just stay away from that Purple Haze

Several times on a dark night, I've found myself in IMC without realizing it!! Since I'm normally IFR, it didn't matter, but it's pretty clear, VFR into IMC is much easier at night, 'specially when there's not a decent moon, or you're under broken to solid overcast, etc. As has been brought up, if there is more light, in the sky or on the ground, it's easier to contrast.

Clear nights with a decent moon are wonderful. Weigh all the elements Beth. The darker, hazier, etc. the more likely you'll need to be on instruments. If the ground is solid forest or water, all the more reason to be careful.

One story: I departed from an airport at night in south Texas on a moonless, overcast night. Immediately after rotation, there was no horizon--none. The airport was in a densely forested area--no lighting. Just felt like I was flying into a void. No light from overhead. Of course, the runway and other lights before takeoff ruined any night vision I might have had.

Immediately went on instruments through the climb until a horizon gradually became evident at a couple thousand feet. I'm not saying I couldn't have some how kept the wings level VFR, but it was much easier on the gauges. Routine instrument flight, but could have been a rude awakening for a VMC pilot.

Best,

Dave

 

[woodstock]

whew! what a story!

the good news is the moon is nearly full, or was a few days ago. it may well be fine tonight. we'll take off around 715 or so, be gone an hour, hour and a half tops, back at 815-845. assuming we start on time.

 

[Dave Siciliano]

You should have a great time. Everything looks much different. Look forward to hearing what you think if it.

Dave

 

[cherokeeflyboy]

What is the illusion of haze illusion ?

Haze gives the illusion of being at a greater distance.

 

[wsuffa]

how much haze would you consider acceptable for a night flight? little/none? do you go by the posted Viz limits (i.e. 6-plus, etc.) or does the indication of any haze throw that out?

Where you live, it's hard to avoid the haze. For training, I'd probably take >6, with the legal 3 miles there's more chance of disorientation. I would suggest that you do your 'flight by reference to instruments' training at the start.

Be careful, though, and know the local conditions.

Here in South Texas, at night, that haze can turn very quickly to ground fog - with near zero visability. I learned that shortly after I moved here. I got back into the home airport on special VFR (for visibility), I had a mile on landing (could see the entire runway), but the layer was building. By the time I got to the hangar, I couldn't see the tower from my T-hangar. I drove home in near zero conditions. It was >6 above 200' AGL.

Have fun!

 

[woodstock]

we did a night flight last Monday - beautiful! all my flights this fall will be night ones, I think - my CFI can't fly on wkds, at least not til his sched changes. Sept is already set in stone.

haze I'm not too crazy about though!!

 

[MSmith]

If the front has passed through, tonight should clear up pretty quickly. Cold front = high pressure = clear at night, sometimes fog near the ground

High pressure = hazy during the day and bumpy in the afternoon

Given my way, I'd ask for clear skies at night and a nice solid overcast at 9000 feet during the day (for VFR short XC's)

 

[mmthomas]

One story: I departed from an airport at night in south Texas on a moonless, overcast night. Immediately after rotation, there was no horizon--none. The airport was in a densely forested area--no lighting. Just felt like I was flying into a void. No light from overhead. Of course, the runway and other lights before takeoff ruined any night vision I might have had.

Immediately went on instruments through the climb until a horizon gradually became evident at a couple thousand feet.

I had exactly this same experience just a couple of weeks in mid-Michigan, out in the middle of nowhere where there were no lights for miles around the airport. Unexpectedly had to go on instruments immediately after rotation. I know I could not have done it VFR, because I found myself in an unintended, fortunately shallow turn to the right which I could correct only by looking at the instruments.

 

[Dave Krall CFII]

What is the illusion of haze illusion ?

Even during nights of severe clear, the illusion of haze is often created by the beams of landing lights, runway lights and the optical distortions of plexiglass windscreens to name a few, causing the same illusional effects as real haze.

 

[Richard]

how much haze would you consider acceptable for a night flight? little/none? do you go by the posted Viz limits (i.e. 6-plus, etc.) or does the indication of any haze throw that out?

I'm currently reading the publication, NAVMC 2614, Professional Knowledge Gained From Operational Experience In Vietnam, 1967 edition. Lo, I just came across a section which is most appropriate to your question.

Listed under "Pilot Procedures" the question is asked, "At what point does the wx become too bad to continue the mission?" The answer given is, "When the situation appears to be making demands that exceed the capabilities of the aircraft or the pilot, it is time to abort. The common tendency is to go too far or to hesitate too long."

Mind you, the question broadly encompasses wx in general, but it is still valid when speaking of specific wx, such as sky obscuring HZ. Notice too how there are several references to pilot skill. The pilot must make use of his experience to adequately determine where the abort point is. Put another way, how does one know they can continue but aren't being suckered into a one way trip?

Staying on the ground is one option in wx avoidance but it won't help you to gain the experience. Your CFI is in the best position to help you make the appropriate decisions at the appropriate times.

 

[woodstock]

after all that we stayed in the pattern.

 

[Shipoke]

Probably a good choice Elizabeth, FLY SAFE Dave

 

[Richard]

after all that we stayed in the pattern.

Better that then staying on the ground. Even in the patt you are gaining experience.

What wx did you experience? What was the TAF, if available?

 

[MSmith]

after all that we stayed in the pattern.

I thought that might happen. My brother called from Jefferson, MD about 6:30 and I asked him about the weather. He didn't think you'd be flying.

 

[Henning]

how much haze would you consider acceptable for a night flight? little/none? do you go by the posted Viz limits (i.e. 6-plus, etc.) or does the indication of any haze throw that out?

Kinda depends on where and what I'm flying. If it's a short flight over a lit area, I'll go VFR. If it's over desert, water... I'll typically fly as I would IFR and airfile if I need to.

 

[woodstock]

it didn't seem too bad really but we stayed in the pattern. where we were, was fine, and allegedly plus-6 viz. however I find that viz in the DC area is a loose term: "hey, I think I can see that tower over there, and it's likely 6 miles away. wait, is that a tower?"

it is interesting doing things at night - but I will say, it compresses certain things - harder to tell how far away something is. when we first took off - dusk - someone was coming into the downwind (extended downwind) as I was still climbing. I decided to keep going straight because a turn to X-W at that point would likely have brought us together on downwind, although he did appear to be fairly far away yet. it was a good call. I didn't have to go as far out as I expected although I did reach TPA before I even turned x-w.

 

[woodstock]

oh yeah, and staying a little high on final is not a bad idea at night either. JYO doesn't have obstructions but other places might. (check out JYO if you are nearby - new runway - new lights - man it looks great!!)

 

[jdwatson]

Even during nights of severe clear, the illusion of haze is often created by the beams of landing lights, runway lights and the optical distortions of plexiglass windscreens to name a few, causing the same illusional effects as real haze.

I hadn't really thought of that. Yes! I agree. Especially landing lights. I remember the illusions that haze can produce, but I had not heard of a haze illusion in this context. I appreciate the clarification.

 

[Dave Krall CFII]

I hadn't really thought of that. Yes! I agree. Especially landing lights. I remember the illusions that haze can produce, but I had not heard of a haze illusion in this context. I appreciate the clarification.

The occurrence of the "illusion of haze" illusion can be quite insidious, since it often is present even in severe clear night wx when the pilot is less on guard than when in visible haze. I've never seen it mentioned anywhere in the aviation illusions texts.

Another related one is thin beach or regular ground fog. Nice & clear above and maybe 1-2 meters of mist or beach/ground fog. Traps pilots regularly at Copalis Beach Airport (S16) when landing on otherwise firm enough, wet ocean sand. Multiple times I've witnessed the results of their relatively minor lack of correction for the illusion which causes otherwise competent pilots to land just too hard enough to jam the nosegear up into the engine compartment or even nose over the entire aircraft.

 

[Dave Krall CFII]

I hadn't really thought of that. Yes! I agree. Especially landing lights. I remember the illusions that haze can produce, but I had not heard of a haze illusion in this context. I appreciate the clarification.

Was doing some more reading here whittsflying and found that for landing lights, it causes some pilots to flare too high...

 

[grattonja]

Was doing some more reading here whittsflying and found that for landing lights, it causes some pilots to flare too high...

I had a taste of haze on final at night last night at Smoketown. I was coming back from a trip over to NJ. It was severe clear except when I turned from base to final at S37. There is a little stream off the arrival end of 28. It was starting to produce what later would be ground fog. It was really disconcerting to see the beam from the taxi light (landing light bulb out) where I had not seen it before. It definitely made finding the runway a bit more difficult in the flare. I did 3 tols, to get night current. The second one I flared a bit high, which in part was this haze ( partly being tired as well). The final landing made up for it.

But the haze definitely has an impact on pattern work. One that I will remember.

Jim G

 

[SCCutler]

When I was a baby pilot, maybe a month after I got the license, my wifey and I flew up to Ardmore, OK for a supper run, flying up in evening light and back in the darkness. I was tempted to turn back when I got to altitude northbound, because while the skies were "clear," the visibility was grunt. Reported 6, but (in hindsight) I doubt it was.

In any event, we got there with no controversy, but the indistinct horizon was very troubling to me.

Coming home, I was severely intimidated by what I feared would be even worse conditions (because of the darkness); but, in fact, because the way home was sufficiently populated that I always had ground lights to see, I had less trouble.

I would be cautiously hesitant to launch night VFR in (1) unfamiliar territory; (2) very sparsely-populated areas; and (3) very hilly or mountainous terrain. The last bothers me the most, because I know that in the approach phase, you might be flying right toward a hill while believeing you are just over a less-populated flat place without lights. First clue otherwise could be the trees that you're about to hit in the landing light.

For unfamiliar areas, if the chart shows any meaningful obstacles, not a bad idea to follow a published approach even when you are VFR.

 

[Richard]

When I was a baby pilot, maybe a month after I got the license, my wifey and I flew up to Ardmore, OK for a supper run, flying up in evening light and back in the darkness. I was tempted to turn back when I got to altitude northbound, because while the skies were "clear," the visibility was grunt. Reported 6, but (in hindsight) I doubt it was.

In any event, we got there with no controversy, but the indistinct horizon was very troubling to me.

Coming home, I was severely intimidated by what I feared would be even worse conditions (because of the darkness); but, in fact, because the way home was sufficiently populated that I always had ground lights to see, I had less trouble.

I would be cautiously hesitant to launch night VFR in (1) unfamiliar territory; (2) very sparsely-populated areas; and (3) very hilly or mountainous terrain. The last bothers me the most, because I know that in the approach phase, you might be flying right toward a hill while believeing you are just over a less-populated flat place without lights. First clue otherwise could be the trees that you're about to hit in the landing light.

For unfamiliar areas, if the chart shows any meaningful obstacles, not a bad idea to follow a published approach even when you are VFR.

My very 1st x/c for the PPL was a night flight. I dutifully noted all the information about the destination aprt and surface area including the row of 90' trees off the approach end. The aprt was a paved unlighted strip with a VASI in an ag rural area with hardly any lights visible. Downwind entry, turning base to final, I suddenly remembered those trees. The fact that everything below and in front of me was black only added to my anxiety. Even though I had the VASI I would not allow myself to descend from TPA.

My CFI was asking if perhaps we should descend? Only when when we were over the numbers did I decide we were clear of the trees. By then it was too late so I got to do my 1st go around which was CFI-initiated. I didn't even have the wherewithal to recognize a bad approach. It was hard to trust those little VASI lights.

By biggest error was not noting the distance of those trees from the rwy. They were actually outside the pattern if properly flown. A return flight in the day revealed how foolish I was.

 

[John J]

For most of my night flight experience I would file IFR . I flew in the New England area for just about 25 years and there were many times the slant visability was.... to say the least was on a good night maybe 2 miles. The tower or ASOS would give you maybe 5-6 miles at ground level. The take offs from places such as EWB, ACK and MVY on the runways that faced the water are the big black hole. I would do Instrument take offs for there was nothing to see once the wheels left the ground. Haze at night is what has gotten so many pilots in trouble. Particujlarly ACK for Runway 24 takes you right out over the water. There are no lights for ground refference.

Now back home on the Eastern Shore of Maryland I still would do instrument takeoffs for there are so little in the way of ground references.

Then there are those special nights when the moon is so bright that it looks like day time and those are the best night for VFR.


John