Winds Aloft Entries

[pcubine 143]

I don’t use average winds for long distance flights in the MD-11 so I make no entry on line 6L of the FLT-PLN INIT page 1. I enter altitude, wind direction, and speed for each waypoint by entering the information on the VERT REV page accessed from the ACT FL-PLN page 2 of 2. This works fine except for flight plans between Europe and the west coast of the United States. A typical flight plan might be 45 waypoint of which 30 are just to get out of Europe, up the North Sea and across the top of Great Britain. So 2/3 of the waypoints account for maybe 10-15% of the flight distance. So an average wind is no good for this flight plan. I have confirmed with HiFi that the average wind in there reports doesn’t take into account the leg distances. So an average is going to be heavily influenced by European winds since AS2012 average is not weighted by leg distance but is just a simple average even though some legs maybe 8 miles and some maybe 350 miles in length . They all count the same in the average.

 

Anyway back to the problem. The CLIMB FORECAST is completed and inserted. To reach top of climb use maybe the first 5 waypoints. So what I am looking at is waypoint 6 to 30. Now I don’t want to be entering winds for waypoints that start a 20 mile leg on a 5000 mile flight. So for waypoints 6-30 I would enter average direction and speed by making that my entry for waypoint 6 and that entry would be propagated thru waypoints 6-45. The next entry would be at waypoint 31 which starts a 300 mile leg. When the entry for 31 is made and inserted it not only propagates 32 to 45 it also propagates backward to waypoints 7. I can get around this by entering the same info in 30 as I did in 6. Waypoint 31 does not change when this is done and it still propagates all the way to 45. I continue on entering and inserting info for 32 to 45 since the legs are of significant length.

 

I know this is not the correct way to enter waypoints 6-30 because I have done it the right way for 2 1/2 years. At least I think it was right. Maybe I have been screwing it up and just never noticed. Any ideas would be appreciated.

 

Thank you

Michael Cubine

[phil747fan 14]

Michael,

 

you need a FO that s why there are here .....

 

the more you feed datas the more accuracy of prediction will be ...

 

note the word prediction .....

 

all the best.

 

Phil

[scandinavian13 5,192]

Michael,

 

You can always create pseudo-waypoints along your route using PBD waypoints or similar. AS2012 won't get your wind reports for those fixes, but you always have Aviationweather.gov's wind page:

http://aviationweather.gov/adds/winds/

 

It's not perfect and requires a little guesswork/interpolation, but that's what aviation (and life) is all about: making a decision using the best information available. In the end, it'll be a little better than what you have now.

[pcubine 143]

I don't beleive I explained the issue correctly. Forget paragraph one. Either the FMS is doing something incorrectly or I am. The basic issue is the wind direction and speed are being propagated not only forward in the flight plan but also backwards to the last entry. In the above example an entry for waypoint 6 which is the average of 6 thru 30 is propagated forward to the end of the plan. However when the entry for waypoint 31 is made it not only propagates to end of the plan it also propagates back to waypoint 7. So waypoint 6 has the average but 7 thru 31 have become the same as 31 when it should be 6 thru 30 the same and then the entry for 31.

 

You think this is confusing, you should try to enter this mess into to the FMS correctly if there are maybe three or for averages between 6 and 30. Sometimes you just say screw it. "Let's get this mother in the air".

 

Thank you

Michael Cubine