Official Night time

[cosworth211]

Hi,

Does anyone know of any websites that publish official night times in various areas? I am currently hour building in Florida and quite often fly somewhere during the afternoon and return as it turns night, but can't always get a definitive answer from ATC at my destination to what time it became night.

(I do not want to log time as night time if it wasn't officially night)

Many thanks.

[Fuji Abound]

There is a very good free software utility here for PcoketPC

http://home.comcast.net/~jonsachs/#Ephemeris%201.0

[helicopter-redeye]

You can calculate it using the Arc to Time formula, based on your location E-W.

h-r:)

[dublinpilot]

This (http://www.nomadelectronics.com/) program for the PocketPC also gives a sun rise/set time for your exact location, based on an inputted lat/long.

[Stan Evil]

As well as knowing when sunset is, you need to know what National rules are regarding when night flying starts. In the UK it is 30 mins after Official Sunset. However, there are 4 different sorts of sunset - official, civil, nautical and astronomical. Some countries may well use civil sunset as the night flying time (it's used in the UK as 'lighting-up time').

[FBS]

Official night is usually about five minutes after the last aircraft lands claiming is is still "just after sunset"!

[RodgerF]

The best site I have found for this is the US Naval Observatory

at http://aa.usno.navy.mil/

It will calculate SR/SS given lat and long for an entire year. This can be downloaded and printed.

[qeduve]

If you're not flying too far, or only flying from A-A, try:
www.cmpsolv.com/los/sunset.html

For calculating/logging the proportions of day/night hours for a flight beginning during daylight and finishing during night time or vice versa:
The easy way is to buy SkyLogPro www.skylogservices.co.uk - it has a strapped on :O (rather than built in) day/night calculator. Because it only allows you to enter chock to chock time, it has to make some assumptions regarding the duration of taxiing time.

The other way is free, tedious, but accurate:
www.teamsamas.com
"This page will calculate combinations of the following:

Great Circle distances between two points.(nautical/statute/kilometers)
The initial true course from A to B.
Sunrise & sunset times in UTC for point A and/or B.
Total voyage time & day/night flight totals required for pilot logbooks.
Average groundspeed (nautical/statute/kilometers) /hour"

The difference in results for the last two methods above is in the order of less than +/-3mins, for taxi durations of 5-10 minutes.

If you do use the second method regularly, building a database of airport lat/longs speeds things up and makes the job more accurate. Speaking of which, does anyone have any links to airport nav data in spreadsheet or csv format with lat/longs listed as 'DDMM.M'? I've started something but the source data is pretty rough in places.

RodgerF's recomendation looks good too. Thanks.