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 |
#11
|
|||
|
|||
How does Winscore calculate finish altitude?
snip the altitude being displayed on the 302 is the same as being
recorded on the GPS /snip John, can you confirm that it's the pressure altitude, not GPS altitude, that's being displayed and recorded? 2NO (finish line fan) |
#12
|
|||
|
|||
How does Winscore calculate finish altitude?
On Jul 27, 1:09 pm, BB wrote:
Yes, actually I did get caught out. I cut the margin a bit too close (My altimeter showed me about 100 ft above the 500', but I suspect my altimeter needs recalibration) so lost some points. A good trick here is to look at the altitude that's being recorded in the GPS rather than the aircraft altimeter. If you have a 302, the altitude being displayed on the 302 is the same as being recorded on the GPS so you know to the last foot exactly what's going on. Most GPS systems can display altitude, you just have to find where it is and look at it. I should have listened to 44 and landed straight in. Less safe, perhaps, but a better race option. In most cases, it's the other way around: an early commitment to a rolling finish is safer than arriving at 501 feet, 1 mile out, and 42 knots, much safer than staring at the altimeter for the last mile or so if you're unsure you'll even make that, and far safer than arriving at a finish line over the center of the airport at 50 feet, 50 knots. Was there something unusual at Ionia that turned this usual advice around? John Cochrane Actually, I was crosschecking my SeeYou Mobile AGL readout with my altimeter. I thought I was just barely above the line. It showed me close to the 500', but there is a definite lag in the display. I may have to reconfigure the display to show straight GPS altitude and practice with that. Again, the problem is that if you are trying to win, you have to spend precious time clockwatching at a critical point of the flight. And on a weak day, 100ft could be as much as a minute. Yeah, it makes a difference! Of course, Winscore doesn't use GPS altitude, but pressure altitude. So you have to hope that there isn't a significant difference between your logger pressure altitude reading while stopped, and while moving (I have yet to see a logger hooked up to a static port - have you? I wonder what the static pressure is in my cockpit on final glide...fast=more ram pressure=lower altitude? It only takes a few feet...). At this particular race, the CD did not set a rolling finish penalty (and was asked to confirm it prior to the flight in question). I would easily have saved 2 - 3 minutes (!) by ignoring the 500' requirement altogether (even though I wasn't really low and slow enough to need to), pushing over to the deck, pulling spoilers crossing the fence, planting my glider on the first piece of runway available, and coming to a screeching halt. Safe? Probably not. Smart racing? Absolutely! That's one of the reasons I really question this finish rule and think it needs to be re-addressed - it's got a few huge loopholes in it! I realize that to some this may seem to be arguing about angels on a pinhead, but in racing, seconds really do count - so we shouldn't have rules that introduce a large unknown in the scoring equation. IMHO, of course ;^) Kirk 66 |
#13
|
|||
|
|||
How does Winscore calculate finish altitude?
On Jul 27, 12:15 pm, Tuno wrote:
snip the altitude being displayed on the 302 is the same as being recorded on the GPS /snip John, can you confirm that it's the pressure altitude, not GPS altitude, that's being displayed and recorded? It's ALWAYS the pressure altitude that's recorded. The altitude displayed on the 302 is pressure altitude adjusted for the local altimeter setting. So unless there is an accurate source of local pressure nearby, it's impossible to know precisely how high you are at the end of the day. -Tom |
#14
|
|||
|
|||
How does Winscore calculate finish altitude?
While Scoring the Region 8 contest I asked this exact question. I
think I talked to Guy about it but now I don't remember, it might have been one of the previous scorers in attendance. I confirmed that the finish alititude is caluclated off the feild elevation at the beginning of the flight. The theory I heard for this is that the pressure typically changes through out the day to make calculating it this way generally give the pilot the benefit of the doubt. I confirmed this on several flight logs that had low finishes, that if it had calculated it on the landing elevation the program would have scored the finish even lower. Now the feature that I and several other pilots disagreed with was scoring a low finish as a Rolling Finish. I am not sure where this practice comes from but it seems like a poor practice to me. It means that the pilot that is 10 feet low on the finish and doesn't realize it get penalized for coming back to the airport and flying a normal pattern because he doesn't realize the clock is still running. What this practice promotes is if a pilot is even close to being low they are encouraged to dive for the runway and land as soon as possible to get the clock stopped. In my opinion the clock should stop as soon as the pilot enters the cylinder. We shouldn't have pilots in the finish cylinder still racing. Brian CFIIG/ASEL |
#15
|
|||
|
|||
How does Winscore calculate finish altitude?
Brian wrote:
I confirmed that the finish alititude is caluclated off the feild elevation at the beginning of the flight. The theory I heard for this is that the pressure typically changes through out the day to make calculating it this way generally give the pilot the benefit of the doubt. I confirmed this on several flight logs that had low finishes, that if it had calculated it on the landing elevation the program would have scored the finish even lower. I looked at the source code for the 2007 version of Winscore, it looks to me like it uses the most favorable (to the pilot) of the field elevation corrections determined by looking at samples from 2 minutes before takeoff, and 2 minutes after landing, to calculate the finish altitude. In my opinion the clock should stop as soon as the pilot enters the cylinder. We shouldn't have pilots in the finish cylinder still racing. That seems like a sensible change to me. In any case, it absolutely defeats the whole purpose of the finish cylinder if the CD does not penalize rolling finishes by an amount greater than the time it would take to climb to the bottom of the cylinder... Marc |
#16
|
|||
|
|||
How does Winscore calculate finish altitude?
In the past, you region 8 guys have used a graduated
finish penalty something like; 100 foot low = 5 points 200 foot low = 10 points 300 foot low = 15 points 400 foot low = 20 points I didn't like it because it wasn't in the rules. Might be time to put something like this in the rules??? I have tried to use GPS pressure altitude and ended up with a penalty. Things get complicated, you must read GPS pressure altitude before flight, note correction (+125 feet or - 236 feet), apply the corrected GPS pressure altitude to the start and finish pressure altitude, then select GPS pressure altitude to view when starting or finishing. Oh, also you need to display the start/finish distance at the same time. Much toooo complicated for me, also like kirk said, the GPS isn't hooked to the ships static system, but your altimiter is, sooooo set it to field elevation before takeoff and use it because it's the most accurate information available, then apply an appropriate margin for error. JJ At 20:18 27 July 2007, Brian wrote: While Scoring the Region 8 contest I asked this exact question. I think I talked to Guy about it but now I don't remember, it might have been one of the previous scorers in attendance. I confirmed that the finish alititude is caluclated off the feild elevation at the beginning of the flight. The theory I heard for this is that the pressure typically changes through out the day to make calculating it this way generally give the pilot the benefit of the doubt. I confirmed this on several flight logs that had low finishes, that if it had calculated it on the landing elevation the program would have scored the finish even lower. Now the feature that I and several other pilots disagreed with was scoring a low finish as a Rolling Finish. I am not sure where this practice comes from but it seems like a poor practice to me. It means that the pilot that is 10 feet low on the finish and doesn't realize it get penalized for coming back to the airport and flying a normal pattern because he doesn't realize the clock is still running. What this practice promotes is if a pilot is even close to being low they are encouraged to dive for the runway and land as soon as possible to get the clock stopped. In my opinion the clock should stop as soon as the pilot enters the cylinder. We shouldn't have pilots in the finish cylinder still racing. Brian CFIIG/ASEL |
#17
|
|||
|
|||
How does Winscore calculate finish altitude?
In my opinion the clock should stop as soon as the pilot enters the cylinder. We shouldn't have pilots in the finish cylinder still racing. You haven't met enough contest pilots. If the rules change in this way, pilots will aim to finish one mile out, 50 feet, 90 knots and then float in to the landing, european-style. If you don't think people racing inside the cylinder is a good idea, then what you want is a "hard floor". 499 feet = distance points only. Now, again, everybody inside 1 mile is done racing, but pilots aim for 500 feet, not for 50 feet. John Cochrane |
#18
|
|||
|
|||
How does Winscore calculate finish altitude?
BB wrote:
In my opinion the clock should stop as soon as the pilot enters the cylinder. We shouldn't have pilots in the finish cylinder still racing. You haven't met enough contest pilots. If the rules change in this way, pilots will aim to finish one mile out, 50 feet, 90 knots and then float in to the landing, european-style. Applying an appropriate penalty for finishing below the Minimum Finish Height would eliminate that behavior. I was actually surprised to find that the SSA competition rules provide no guidelines as to how to penalize pilots who don't make it into the finish cylinder. Given the difficulties of knowing precisely how high one is finishing, missing by 50 or so feet shouldn't result in a huge penalty, but it should also never be beneficial to intentionally finish low... Marc |
#19
|
|||
|
|||
How does Winscore calculate finish altitude?
A question: How does Winscore calculate finish altitude on a cylinder
finish? Winscore calculates altitudes and finish heights according to SSA Contest rules 6.7.4.3 and 11.2.1.5.1. 6.7.4.3 If a Flight Recorder records both calculated and pressure altitude, pressure altitude will be the primary data source and calculated altitude will be the backup data source for flight evaluation. 11.2.1.5.1 When the Scorer must measure a pilot's height above ground level (AGL), this height shall be the difference between a recorded fix and that of a fix recorded on the ground. For all purposes except finish height, a fix prior to takeoff shall be used. For finish height, the Scorer shall use the more favorable of a pre- takeoff or post-landing fix. Guy Byars Author of Winscore |
#20
|
|||
|
|||
How does Winscore calculate finish altitude?
On Jul 28, 6:44 am, wrote:
A question: How does Winscore calculate finish altitude on a cylinder finish? Winscore calculates altitudes and finish heights according to SSA Contest rules 6.7.4.3 and 11.2.1.5.1. .... Guy Byars Author of Winscore Winscore calculates altitudes and finish heights according to SSA Contest rules 6.7.4.3 and 11.2.1.5.1. ... Guy Byars Author of Winscore What does winscore do about 6.7.4 Altitude recording 6.7.4.1 A Flight Recorder may record altitude derived from a calculated position. The estimated altitude inaccuracy shall be applied in a way unfavorable to the pilot (if the flight log does not include a reliable estimate of this inaccuracy, a value of 75 feet shall be used). 6.7.4.2 A Flight Recorder may record a calibratable pressure altitude. If such a device is used in circumstances where altitude is needed, the altitude inaccuracy determined from the best available calibration data shall be applied in a way unfavorable to the pilot. 6.7.4.3 If a Flight Recorder records both calculated and pressure altitude, pressure altitude will be the primary data source and calculated altitude will be the backup data source for flight evaluation. I've never really understood these rules. Does winscore subtract 75 feet from GPS altitude in deciding if you get a penalty (or add it for start gates and 17500?) I've never submitted calibration data at a contest, does 6.7.4.2. apply anywhere? John Cochrane |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
WinScore Question | Ray Lovinggood | Soaring | 2 | June 5th 07 03:15 PM |
calculate last point of diversion | jaws | Piloting | 1 | July 5th 06 04:19 PM |
How to calculate TOC and TOD? | Andrea da lontano | Piloting | 3 | October 21st 04 09:24 PM |
Weight and Balance Formula, Can one calculate the envelope | Joe Wasik | Piloting | 12 | September 29th 04 08:15 AM |
Winscore source code now available | Guy Byars | Soaring | 0 | February 5th 04 10:43 AM |