![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
![]()
Since most of us that fly cross country (or locally as weel), and are
restrained by the FAR's to be on the ground before sunset assuming that we don't have position lights. Since most of us use some kind of navigational devise (SeeYou, Glide Navigator, WinPilot etc.), I am wondering if any of these programs utilize some data showing sunset at the region one happens to be in? I am running WinPilot, and not aware of of any data availabe in conjunction with it. What is everybode else doing?? 6PK |
#2
|
|||
|
|||
![]()
On Apr 19, 9:05*am, PK wrote:
Since most of us that fly cross country (or locally as weel), and are restrained by the FAR's to be on the ground before sunset *assuming that we don't have position lights. Since most of us use some kind of navigational devise (SeeYou, Glide Navigator, WinPilot etc.), I am wondering if any of these programs utilize some data showing sunset at the region one happens to be in? I am running WinPilot, and not aware of of any data availabe in conjunction with it. What is everybode else doing?? 6PK SeeYou Mobile displays sunrise and sunset on one of the stats pages. There are various (free) sunrise/sunset calculators for the iPhone and probably other platforms. The US Naval observatory will generate tables you can print out if you need an "official" time. Darryl |
#3
|
|||
|
|||
![]()
On Apr 19, 12:05*pm, PK wrote:
Since most of us that fly cross country (or locally as weel), and are restrained by the FAR's to be on the ground before sunset *assuming that we don't have position lights. Since most of us use some kind of navigational devise (SeeYou, Glide Navigator, WinPilot etc.), I am wondering if any of these programs utilize some data showing sunset at the region one happens to be in? I am running WinPilot, and not aware of of any data availabe in conjunction with it. What is everybode else doing?? 6PK My system is very crude. I use a Garmin 12xl to drive a B50 which in turn drives my PDA. One of the 12xl screens displays official sunrise and sunset for the current coordinates. Switching 12xl screens does not effect NMEA data or the PDA presentation. So if I need the sunset time, I simply select to the sunrise/sunset screen on the Garmin. Wayne http://www.soaridaho.com |
#4
|
|||
|
|||
![]()
On Apr 19, 10:24*am, Wayne wrote:
On Apr 19, 12:05*pm, PK wrote: Since most of us that fly cross country (or locally as weel), and are restrained by the FAR's to be on the ground before sunset *assuming that we don't have position lights. Since most of us use some kind of navigational devise (SeeYou, Glide Navigator, WinPilot etc.), I am wondering if any of these programs utilize some data showing sunset at the region one happens to be in? I am running WinPilot, and not aware of of any data availabe in conjunction with it. What is everybode else doing?? 6PK My system is very crude. *I use a Garmin 12xl to drive a B50 which in turn drives my PDA. *One of the 12xl screens displays official sunrise and sunset for the current coordinates. *Switching 12xl screens does not effect NMEA data or the PDA presentation. *So if I need the sunset time, I simply select to the sunrise/sunset screen on the Garmin. Waynehttp://www.soaridaho.com One of the problems we've seen is that there is really no such thing as an "official" sunset time, just times calculated from astronomical tables based on a lat/long on the earth's surface. Although these agree with each other reasonably well, they use geometric approximations of the earth's shape. Even over sea, there is an uncertainty of a minute or so over the time the sun actually sets because of differences in atmospheric refraction. In mountainous country (like we are in Arizona), actual sunset time can differ from that calculated in tables by many minutes. This has led to some grumbling when flights were disallowed because landing occurred after a calculated sunset, but before an actually observed sunset. Another wrinkle at our home field is that our prevailing winds have us land to the west on our main runway and this is definitely easier and safer just after sunset than just before it, when the setting sun would be in your face. Fortunately for us, mountains to our west result in sunset at the field before the computed sunset for our location, so folks looking at the "official" sunset time don't ding us. Presumably, though, we should still show position lights if we land after the sun has actually set at our field. Mike |
#5
|
|||
|
|||
![]()
On Apr 19, 11:48*am, Mike the Strike wrote:
On Apr 19, 10:24*am, Wayne wrote: On Apr 19, 12:05*pm, PK wrote: Since most of us that fly cross country (or locally as weel), and are restrained by the FAR's to be on the ground before sunset *assuming that we don't have position lights. Since most of us use some kind of navigational devise (SeeYou, Glide Navigator, WinPilot etc.), I am wondering if any of these programs utilize some data showing sunset at the region one happens to be in? I am running WinPilot, and not aware of of any data availabe in conjunction with it. What is everybode else doing?? 6PK My system is very crude. *I use a Garmin 12xl to drive a B50 which in turn drives my PDA. *One of the 12xl screens displays official sunrise and sunset for the current coordinates. *Switching 12xl screens does not effect NMEA data or the PDA presentation. *So if I need the sunset time, I simply select to the sunrise/sunset screen on the Garmin. Waynehttp://www.soaridaho.com One of the problems we've seen is that there is really no such thing as an "official" sunset time, just times calculated from astronomical tables based on a lat/long on the earth's surface. *Although these agree with each other reasonably well, they use geometric approximations of the earth's shape. *Even over sea, there is an uncertainty of a minute or so over the time the sun actually sets because of differences in atmospheric refraction. *In mountainous country (like we are in Arizona), actual sunset time can differ from that calculated in tables by many minutes. *This has led to some grumbling when flights were disallowed because landing occurred after a calculated sunset, but before an actually observed sunset. Another wrinkle at our home field is that our prevailing winds have us land to the west on our main runway and this is definitely easier and safer just after sunset than just before it, when the setting sun would be in your face. *Fortunately for us, mountains to our west result in sunset at the field before the computed sunset for our location, so folks looking at the "official" sunset time don't ding us. *Presumably, though, we should still show position lights if we land after the sun has actually set at our field. Mike It may be semantics but the problem some pilots run into is there is *exactly* a precise definition of sunset time, it's just too bad it might be different from what they observe because of what you mention. Which is why I assume the OP is after a tool that gives pilots "official times" (which for us in the USA are the US Naval Observatory times -- i.e. Judy will look at http://aa.usno.navy.mil/data/docs/RS_OneDay..php for your badge or record flight). SeeYou seems to be close (~1 minute) to the naval observatory tables when I checked, I presume Garmin gets this right. Hopefully everybody understands there is absolutely no leeway on this, if you are outside the official sunset times by even a small amount you are going to have problems with badges and records. Darryl |
#6
|
|||
|
|||
![]()
I can't tell how important that "sunset" time really is. I HATE
having a long flight not be counted because of 2 or 3 minutes! Judy (The badge Lady) is very precise in her checking of the sunset times. Please don't fall in that trap. I had a pilot in Logan Region 9 North in 2009 that stayed out and out and out...and finally landed 2 minutes before official sunset...WHEW!!!!!!! |
#7
|
|||
|
|||
![]()
On Apr 19, 4:54*pm, MickiMinner wrote:
I can't tell how important that "sunset" time really is. *I HATE having a long flight not be counted because of 2 or 3 minutes! *Judy (The badge Lady) is very precise in her checking of the sunset times. Please don't fall in that trap. *I had a pilot in Logan Region 9 North in 2009 that stayed out and out and out...and finally landed 2 minutes before official sunset...WHEW!!!!!!! I had a 1000km flight at Mifflin that I had to abort because of the approaching sunset. I was comparing SeeYou Mobiles sunset with my expected finish time and just did not have time to make the last turnpoint ( just south of the wall ) and then return to Mifflin before dark. I still was able to claim a 750km flight ( out of 950km flown ) because I landed before sunset. And I didn't have to fly the Raystown resevoir in the dark !!! Todd |
#8
|
|||
|
|||
![]()
Darryl Ramm wrote:
/snip/ One of the problems we've seen is that there is really no such thing as an "official" sunset time, just times calculated from astronomical tables/snip/ Mike It may be semantics but the problem some pilots run into is there is *exactly* a precise definition of sunset time, it's just too bad it might be different from what they observe /snip/ Darryl I have run into a definition of sunset that used to go like this: "The time at which the trajectory of the Solar center is six degrees below the local horizon." You can see how this could vary when the horizon is the Rockies, versus five miles West where it might be 5000 ft lower... Brian W |
#9
|
|||
|
|||
![]()
On Apr 19, 8:14*pm, brian whatcott wrote:
Darryl Ramm wrote: /snip/ One of the problems we've seen is that there is really no such thing as an "official" sunset time, just times calculated from astronomical tables/snip/ Mike It may be semantics but the problem some pilots run into is there is *exactly* a precise definition of sunset time, it's just too bad it might be different from what they observe */snip/ Darryl I have run into a definition of sunset that used to go like this: "The time at which the trajectory of the Solar center is six degrees below the local horizon." You can see how this could vary when the horizon is the Rockies, versus five miles West where it might be 5000 ft lower... Brian W Stop tying to make this hard, there is one proper definition to worry about for gliding in the USA. That is the table generated by the US Naval Observatory. The FARs define sunset times as published in the Air Alamanac which is produced by the US Naval Observatory, but for practical purposes the official data is the USNO tables I provided the link to. Those tables are exactly what is used for badge and records flights in the USA and are the numbers glider pilots need to worry about (unless the glider is one of the few equipped with lights and appropriate certification, etc. to fly until the end of civil twilight, in which case the USNO has civil twilight tables as well). Darryl |
#10
|
|||
|
|||
![]()
Darryl Ramm wrote:
/snip/ You can see how this could vary when the horizon is the Rockies, versus five miles West where it might be 5000 ft lower... Brian W Stop tying to make this hard, there is one proper definition to worry about for gliding in the USA. That is the table generated by the US Naval Observatory. The FARs define sunset times as published in the Air Alamanac which is produced by the US Naval Observatory, but for practical purposes the official data is the USNO tables /snip/ Darryl I have no problem with competitive sporting endeavors adopting a uniform definition of anything they choose to. But supposing that the Official Definition of Sunset from the USNO and the ACTUAL sunset time, as described by the USNO, always coincide for a particular place and time would be an over simplification. At times, a LETHAL over-simplification. Take this NTSB accident investigation from April 15th, 2002 for example. http://www.ntsb.gov/recs/letters/2002/A02_08.pdf Here an aircraft landing in the Rockies failed to note an intervening summit. It was subject to a LOCAL sunset that was 25 minutes earlier than the official sunset time as pointed out by the USNO in a footnote, mentioned in this report. Brian W |
|
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Sunrise | Patrick R7 | Aviation Photos | 2 | October 19th 08 11:10 AM |
Col. Robert Bowman, PhD, U.S. Air Force (ret) - Director of Advanced Space Programs Development under Presidents Ford and Carter. "A lot of these pieces of information, taken together, prove that the official story, the official conspiracy theor | Custard Cream | Naval Aviation | 10 | July 14th 07 06:51 PM |
Sunrise, Sunset -- the real data, for anywhere in the world | [email protected] | Piloting | 8 | June 30th 07 02:59 AM |
Jet Sailplane at Sunset | Bob C | Soaring | 0 | June 27th 07 07:16 AM |
Japan Airlines_Early Bird Sunrise | Ducky | Aviation Photos | 0 | February 8th 07 07:31 AM |