Landing into sun

[fireflybob]

Last night we had a spectacular sunset round our neck of the woods.

The last 45 minutes or so before sunset was quite an interesting time to attempt landing on our south westerly runway. The runway was barely visible until about half a mile from touchdown.

This got me thinking about this issue. They say no question is too dumb so here goes! What specfically causes the apparent reduction in visibility in this case? (I am, of course, aware that vis into sun is worse than down sun).

For students, other than a Go Around and request for an alternate runway what gems of advice has anyone got out there?

Thanks for any help.

[Runaway Gun]

If you wish to land into the sun, it's best done in Winter as it's a bit cooler.

[sapperkenno]

Dirty/damaged windscreens don't help.

[flarepilot]

the windshield being dirty, damaged, or flawed makes landing into sun even harder

if you had a perfect windshield you would have the sun to contend with and you could sort of deal with it, but a dirty windshield really makes the situation worse, all the crazing distorts your view.

now imagine looking into the sun for a five hour transcontinental flight, suddenly descending into semi dusk right on the ILS, clear to land and BAM you hit another plane that is on the runway.

your eyes have to adapt from sun to dusk and you trusted ATC


it all happened at LAX

[BigEndBob]

http://i1175.photobucket.com/albums/r624/bigendbob/2013-12-08162417_zps0a58baac.jpg (http://s1175.photobucket.com/user/bigendbob/media/2013-12-08162417_zps0a58baac.jpg.html)

That Sunday evening looking 220 degrees. Picture doesn't do it justice. The sky was very red.

[Whopity]

What specfically causes the apparent reduction in visibility in this case?The direct light from the sun exceeds the reflected light from the ground by a margin that exceeds the dynamic range of the optical nerve. Much the same occurs with a camera. If you move your focal point away from the light source so that you use your periferal vision, you should be able to see more.

[athonite]

Yes I think this is probably has something to do with the physiology of the eye, perceptual psychology and the condition and how clean the screen is also a factor. I am always amazed though the reluctance of pilots to request and alternative runways when wind limitations are not a factor.


Oddly I remember a FI examiner, based at Tollerton (Nottingham) had a particular thing on renewals, about the screen being cleaned prior to a FI exam. He took kindly to FI candidates turning up with a bucket and sponge as well as cream cakes for the debrief.


This examiner I will never forget, as on my initial AFI exam, demonstrated an exceptionally slow entry into a barrel roll in a Beagle Pup.


Of course, I'm sure FireFlyBob as well as others will know who I am referring to!

[Whopity]

The retina has a static contrast ratio of around 100:1 (about 6.5 f-stops). As soon as the eye moves (saccades) it re-adjusts its exposure both chemically and geometrically by adjusting the iris which regulates the size of the pupil. Initial dark adaptation takes place in approximately four seconds of profound, uninterrupted darkness; full adaptation through adjustments in retinal chemistry (the Purkinje effect) is mostly complete in thirty minutes. Hence, a dynamic contrast ratio of about 1,000,000:1 (about 20 f-stops) is possible.[5] The process is nonlinear and multifaceted, so an interruption by light merely starts the adaptation process over again. Full adaptation is dependent on good blood flow; thus dark adaptation may be hampered by poor circulation, and vasoconstrictors like tobacco I recall the days when RAF crew coaches had pre-ox equipment so we could improve out night vision by breathing 100% oxygen for half an hour!

[fireflybob]

Of course, I'm sure FireFlyBob as well as others will know who I am referring to!

athonite, that could only be one person!

[Genghis the Engineer]

I don't disagree with anything above - but the best advice I can offer from personal experience (apart from land on another runway - but that's seldom much good where I am, where the prevailing wind 90% of the time aligns with the setting sun), is to wear a baseball cap and pull it down so the brim is just below the edge of the sun. Messes up general lookout, but improves the view of the runway massively.

G

[jumpseater]

If your landing field has lights, ask for them to be turned on. :ok:

[1Bingo]

You can't see the runway for the same reason you can't see the bandit coming out of the sun to shoot you.

If wind is not a factor, recommend opposite or alternative runway, hold until sun is not a factor or divert.

[Capetonian]

Wasn't one of the contributory causes of the Afriqiyah crash at TIP from JNB that they were landing into the sunrise?

[SawMan]

One of the enhanced vision techniques taught in certain US military classes is to not look directly at what you are trying to see, rather look slightly beside it, below it, or both. Focusing on a point slightly nearer or farther away than the object you want to see may also help. This has to be practiced as no two people will find the same 'aiming point' correct and it is not the natural vision process. It is not something you can do without practice! This also develops your peripheral vision acuity because in effect, this is the part or your vision you use to do this. Learning the technique is best done at night (in someplace safe, not while doing anything more dangerous than walking) where the 'target' is a known size, shape, and distance away but blends in with the background or surrounding objects. Scan slowly till you first see the 'target' and you'll notice that you're not looking directly at it, and that when you do it disappears again! This technique also works when looking into the sun, but is less effective in light than in the dark for some reason. It still enhances your vision though. Being that I learned this second-hand from a Special Forces friend long ago, I can't much better explain it other than to say that once you master the technique, you will be amazed at how much more you will see that was always there which you have simply been missing so far.

Eye health also matters. I take a bilberry and lutien supplement and get enough carotene in my diet. The effect here is more slow-acting and is more important for your night vision- special bilberry jam rations were issued to pilots of night bombers in WW2 as this was the best source they had back then. I began this routine when I was 45 and I was having trouble seeing the road markings at night in the rain. Two months later I could see them as well as I could at 25- quite a difference- and at 55 now it's almost that good. Give this a couple months to work but you'll notice an improvement begin in 2-3 weeks.

I'm neither a 'whacko' or a pilot, I just know that all this really works and I hope it can help others gain some extra safety as it has done for me.

[Agaricus bisporus]

Carrots are of no use to your vision unless you are suffering a lack of vitamin A. If you are not, they will make NO difference. If you are suffering a lack of vit A there are lots of ways of sorting that out apart from carrots.

See wiki, as ever...

Lack of vitamin A can cause poor vision, including night vision, and these can be restored by adding vitamin A to the diet. An urban legend states that eating large quantities of carrots will allow one to see in the dark. This myth developed from stories about British gunners in World War II, who were able to shoot down German planes at night. The rumour arose during the Battle of Britain when the RAF circulated a story about their pilots' carrot consumption in an attempt to cover up the discovery and effective use of radar technologies in engaging enemy planes,

[janrein]

Fireflybob,

One may consider:

- Request opposite runway indeed, wind permitting.

- Considering that the worst situation is when the sun is almost at the lowest, simply delay your arrival a bit so as to be on final a few minutes AFTER SS. When there is a hill somewhere between runway and horizon, that hill will take out the sun problem some minute(s) earlier than SS (some have "night" defined as "after SS"(!), rather than ICAO definition "after End of Evening Civil Twilight").
When already on final and then realising to be squinting into a blinding sun, your GO-AROUND, then same thing.
Or - with more anticipation - plan to arrive before the sun is so low.

- On short final set up for a slow flight with a power setting giving you typically 200 fpm RoD. Maintain airspeed and power until the mainwheels hit the runway, then close the throttle. Slow flight gives you the attitude for avoiding noseweel landing. The technique is from seaplane flying for "glassy-water" landings, but worked fine for me in an into-sun landing.
If unfamiliar, finding suitable airspeed, flap (10º, 20º) and power setting can be practiced at altitude.
BTW you need more than normal runway length depending on where on final you initiate the procedure and because you basically do not know where you are going to touch down.

jr

[Darfung]

we have this problem in the UK especially in the winter evening flights and the runway is 24
what I would suggest is that if the winds by that time are pretty light and variable
ellect to land with a slight tailwind on runway 03 at least you have a much better control and see what you are doing
and worst comes to the worst there is always always a go around

[Oceanic815Pilot]

I always have my eyes closed when I land anyway so I don't find the sun an issue at all.

[South Prince]

always thought you are exceptionally smart Oceanic