Sunrise/sunset

[Guest Marius Grobler]

Hi there all

 

We know that last landing time for VFR is 10 mins before sunset...but what is the first takeoff time? Is it sunrise or some time after that?

 

 

[Guest airsick]

I think this pretty much covers it.

 

AIP 1.1.2

 

Unless the pilot in command holds a Command Instrument Rating or night VFR (NGT VFR) rating and the aircraft is appropriately equipped for flight at night, a VFR flight must not depart from an

 

aerodrome:

 

 

 

a. before first light or after last light; and

 

 

 

b. unless the ETA for the destination (or alternate) is at least 10 minutes before last light after allowing for any required holding.

 

 

 

 

 

And technically speaking it is not sunset or sunrise that matters, it is last light and first light. These times differ from sunrise and sunset.

 

 

[Guest Marius Grobler]

Thanks mate

 

 

[Captain]

And bear in mind that if it is getting close in the evening, it can still be well within last light at 5000 ft and bloody dark + non-compliant underneath you at ground level, and particularly by the time you get the thing down.

 

 

[Guest Marius Grobler]

Got it. I'll keep that in mind.

 

Peace

 

 

[Matt]

Understand Captain's point about the actual amount of light available, but legally speaking, last light is last light as per the prescribed time for that day and if you land before it but it's "dark", you are still compliant with the regulations.

 

 

[Guest Marius Grobler]

Right! So, if the Official Last Light is at 6:15 PM and I land at 6:14 PM then it's legal; irrespective of the ACTUAL physical conditions...?

 

 

[Matt]

Yep, it is legal. Doesn't necessarily mean that it's the best thing to be doing - a good approach is to fly to the conditions, not just within the rules.

 

 

[Guest Marius Grobler]

Right! :thumb_up:

 

Common sense! I'll be sure to be safe

 

 

[PaulN]

A timely topic. Only this evening I was programming my GPS. While there I checked for first/last light but it (Jepperson) lists sunrise/sunset. So I looked up NAIPS to compare and found that for today at Cooma first light is 28 mins earlier than sunrise and last light is 26 mins later than sunset.

 

Sounds logical. Is this right?

 

Paul

 

 

[Guest airsick]

Spot on Paul. This is what I was getting at in my earlier post. Sun goes down past the horizon (sunset) but it is still light. Conversely for morning it gets light just prior to the sun coming up over the horizon. If you work off sunset you will have a good 'safety' margin, especially if you plan for ten minutes prior to sunset for landing.

 

 

[motzartmerv]

But, we've missed one important factor..Cloud. The first/last light publicised doesn't take tat into account.. On overcast days the light dissapates much earlier then quoted.. Its not uncommon to see it black just after sunset or even before..Just something to bear in mind..

 

cheers

 

 

[Admin]

But, we've missed one important factor..Cloud. The first/last light publicised doesn't take tat into account.. On overcast days the light dissapates much earlier then quoted.. Its not uncommon to see it black just after sunset or even before..Just something to bear in mind..cheers

http://www.recreationalflying.com/forum/showthread.php?t=3044&highlight=lesson

 

 

[motzartmerv]

Ian, yea i remember reading your thread..Great story (especially ending well).. Its a real problem isn't it.. It was probably still legal because of the last light documented, but far from legal ( i pressume) from a vfr minnima standpoint..

 

But whats a guy to do, we can only plan from info we have available..

 

And guys, please don't bombard me with the obvious "you should leave more time"

 

cheers

 

 

[Seal]

Understand Captain's point about the actual amount of light available, but legally speaking, last light is last light as per the prescribed time for that day and if you land before it but it's "dark", you are still compliant with the regulations.

That is undoubtedly true and the Captain's post also contains a warning about a trap for the unwary. Around the time of sunset and after, the available light changes rapidly with altitude. Although you may be stooging along at 5000', or even 2000', thinking "what's all this last light stuff, its still broad daylight" beware that as you descend it will rapidly get darker. On final you will be peering at a dark ground against a bright sky and it will be difficult to see obstacles or judge your flare and holdoff. If you happen to be landing anywhere towards the sunset then it will be even worse.

 

Cheers, Selwyn

 

 

[Guest brentc]

Right! So, if the Official Last Light is at 6:15 PM and I land at 6:14 PM then it's legal; irrespective of the ACTUAL physical conditions...?

Yes. It would also be legal to land at 6:20pm IF your plan had you landing at 6:04pm. Herein lies the catch 22 in that you need to plan to land 10 mins before last light, however weather or conditions beyond your control may make you late, but you probably won't have any night experience and might end up doing something silly by landing elsewhere in an unfamiliar location with limited light. In the US a Night VFR rating is issued with the PPL by default, so this would go a way to alleviating this concern. It's like the age old debate over whether or not you should be well taught on how to not get in a spin, or should you be taught how to get out of a spin. I hope that makes sense!

 

 

[Ben Longden]

A quick check of astronomical tables will give you rise and set times, but the one to look for is called "civil twilight'.

 

(If its cloudy, does that mean its uncivil?)

 

Ben

 

 

[Guest airsick]

The one to look for is 'last light' as given by NAIPS! :)

 

Easy to get, nearly impossible to misinterpret and hard to argue with in terms of the law.

 

 

[pylon500]

Don't forget to check the location of last light as it varies when you travel North or South.

 

Twilight can be nearly six months in Antarctica!

 

But very short in Darwin.

 

Arthur.

 

 

[PaulN]

That's the beauty of using NAIPS ... simply key in the location you need to know about, day, month and year then hey presto up comes first and last light for that given location in zulu time. But of course we all only use this to check our calcs from the Daylight and Darkness Graphs as taught in Nav school, don't we :raise_eyebrow:.

 

 

[Yenn]

Two things.

 

Using the graphs will give you a time but it has to be corrected for Longitude. One degree is equal to 4 minutes, so at YGLA Gladstone E 151 deg 13.4 min we are 5 minutes ahead of Eastern Standard time.

 

The other thing is if you are going to arrive 5 mins before last light and there is a herd of cattle on the strip, it could well be after last light when you land, a lessom I learnt a long while ago.

 

 

[tangocharlie123]

Hi Great topic

 

Firstly I am not against the rules that we fly under.

 

Should we do a portion of training on landing planes on last light in the syllabus as as some have said enviromental issues may prevent us from landing on time thus last light comes and then we become unstuck..

 

Should we also have a landing light on our planes so that if this occurs we have some chance of landing safley..

 

Its just a saftey issue and should we address this with RAA..

 

Cheers Peter

 

 

[facthunter]

Landing/ Runway lights.

 

I wouldn't recommend landing after dark without runway lights, or at least illuminate the runway with several car lights, at the threshold and pointing away from you. This would be an absolute emergency, and I cannot conceive how environmental factors could get you into it, if you plan, manage your flight properly (and legally).

 

On a sealed, wet runway , landing lights are not much help anyhow, as you only get an effect when you are quite low. The runway lights provide you with most of the visual cues that you rely on. Nev..

 

 

[tangocharlie123]

Herein lies the catch 22 in that you need to plan to land 10 mins before last light, however weather or conditions beyond your control may make you late, but you probably won't have any night experience and might end up doing something silly by landing elsewhere in an unfamiliar location with limited light!

To quote Yenn as well

 

The other thing is if you are going to arrive 5 mins before last light and there is a herd of cattle on the strip, it could well be after last light when you land, a lessom I learnt a long while ago.

 

It is these sort of reasons that shouldn't we be taught.

 

Nev

 

It is great to hear your views as an instructor but here in Darwin we have very limited places to land mostly bush strips. While on a recent trip I had picked a private landing strip to refuel but with about 50+ cows on the strip none of them moved, I had to do a precautionary landing on a road. We are taught that and it can be used before last light. I was just lucky I was following a major road.

 

Cheers Peter

 

Ps I guess you have taken Mannys course in advanced navigation I too would like to do this but Distance is a problem..

 

 

[Guest peterf]

Visualisation

 

Hi Guys,

 

a long time ago I wrote a program to calculate and help visualise first/last light and sun rise/set for any location on Earth.

 

If you're interested, have a look at

 

[/url]

 

[/url]http://planofile.com/Earth.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-Peter