Primarily for general aviation discussion, but other aviation topics are also welcome.
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By TheFarmer
#1808968
Is it my imagination, or does it get darker ‘faster’ in the winter than in the summer?

What I mean is that during the summer months, I comfortably have a good 30 mins of daylight left after ‘sunset’, and getting home is done easily in decent light when I’m landing 20-25 mins after sunset.

Recently though, by the time it’s official sunset it’s pretty dim already, and by the time SS+30 arrives, it’s nearly pitch black, and hardly VFR flyable at all.

A couple of afternoons ago I was very nearly caught out, and have now made SS my cut off until a few weeks after the shortest day.

Can some of you clever IR lot shed some light on whether darkness falls faster at this time of year?
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By TheFarmer
#1808982
Thanks Iceman. So it’s zero seasonal difference at the equator and exaggerated the further north you go.

Misc must get about 3 mins to land after SS in the winter !
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By Irv Lee
#1808983
Memories stirred. My French goddaughter asked me this (pre Google) as she had to find out as part of her homework. At the end of a minute of seriouly concentrated attention, I thought I had done quite well considering, she sat back, looked at her parents and just said "pas un mot".
By Bill McCarthy
#1808986
At 15.15 on the shortest day up here it does get dark very quickly. Sun up at 09.15 ish.
By Ibra
#1808987
"Darkness time" is function of year date, latitude, surrounding terrain, clouds oktas and sunset time, street lights activated by a photovoltaïc cell will give the right time on the clock given all those conditions, the only thing that will stay random is cloud & pollution effect, overall this can go from SS-10min in tick low cloud day in rhone valley to SS+3h in summer blue sky

"Night time" is SS+30, an easy legal definition and hipefully that to stay that way, it's the average of darnkess time

IFR or VFR does not really matter if lights are not there, even on IFR you have to acquire visual clues to flare NO? what you can fly after SS+30 depends on your LED lights and runways markings, even those with IR anf SyntheticVision or Radio Altimeter can do better for approach but they still the flare is done on real runway surrounding & marking & surface :D ?
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By Flyin'Dutch'
#1808989
Ibra wrote:
IFR or VFR does not really matter if lights are not there, even on IFR you have to acquire visual clues to flare NO? what you can fly after SS+30 depends on your LED lights and runways markings, even those with IR anf SyntheticVision or Radio Altimeter can do better for approach but they still the flare is done on real runway surrounding & marking & surface :D ?


How quaint.

Does your ap not do that for you?

:shock:
AndyR, Ibra liked this
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By Trent772
#1808991
The other explanation is the relative speed of the earth with latitude. It is fatter at the equator, (oblate spheroid if you wish to get picky) therefore goes faster - hence why a lot of rockets are launched close to equatorial regions - free speed.

If you go to say Barbados, the sunset is very quick indeed, almost blink and you miss it. Sooooo, there we were, on said beach drinking rum punches and one of the crew said why does it go dark quickly.

As the "Commander", I was tasked to explain and despite at least a couple of libations, said as per above. This particularly less blessed lass absolutely refused to believe it, despite her colleagues getting it. She wandered off into the rapidly darkening night muttering..... :clown:
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By Flintstone
#1809015
Ibra wrote:even those with IR anf SyntheticVision or Radio Altimeter can do better for approach but they still the flare is done on real runway surrounding & marking & surface :D ?



Or follow the flare cue on the HUD. :wink:
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By Dave W
#1809016
In GA, a high pitched audio cue from around my right ear has stood me in good stead for decades.

On an unrelated note, does anybody else find that their landings are a tad firmer when solo?
AlanC, T6Harvard liked this
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By Trent772
#1809019
It's pre Omgomulator, ignore. Earlier version I believe. The latest ones have Nubulators for a better flat flare compensation.
Flintstone, rohmer liked this
By Ibra
#1809030
Flintstone wrote:
Ibra wrote:even those with IR anf SyntheticVision or Radio Altimeter can do better for approach but they still the flare is done on real runway surrounding & marking & surface :D ?



Or follow the flare cue on the HUD. :wink:


I use certified blind stick that I extend from the PIC window, it's way more cheaper :lol:
Flyin'Dutch' liked this
By Boxkite
#1809032
Sunset is slower in the winter because of the shallow angle at which it crosses the horizon, and vice versa. It just seems darker because of all the rotten weather we've been having .
Stu B liked this