TonyC,
Thanks for the reply. My comments are listed below.
Originally Posted by TonyC
Reviewing your post, I see you've said you noticed a difference in points of up to ten miles. I don't see that. I see the same points as before. What discrepancies do you see, specifically? Could there be an error in your charts?
The Charts that I'm looking at were downloaded off of AirNav.com. The dates, serial numbers and etc. all correspond to the FLIPs at work that are printed in paper/bound format.
Compare the BEERT 1 Arrival with the GILMORE 3 Arrival. Now take a look at the FSM Transition from FSM to HERTZ Intersection. The GILMORE Arrival indicates the FSM R-076, while the BEERT Arrival indicates the the FSM R-082. That's six degrees difference over the course of 103 miles between FSM and HERTZ.
We have a tool at the sector that allows us to plot these angular differences. According to my plots last night at work, there is a 9.53 mile difference in the location of HERTZ between the two arrivals. I'm not up to speed on the formulas required to calculate this by hand. 9.53 miles is fairly significant in my world of ATC.
Originally Posted by TonyC
I'm a bit puzzled why the holding patterns are different, though. On the WLDER 4, the inbound course for the published holding pattern at SPKER is 225 degrees. On the corresponding RNAV arrival, the LTOWN 1, the inbound course is 226 degrees. I don't understand why these would differ. The holding pattern at MRCEL is the same on the WLDER 4 and the LTOWN 1 (RNAV). Oh, there's one more thing. The LTOWN 1 (RNAV) specifies an OUTBOUND leg length of 7 NM for both patterns. I've never seen that before.
Yes, it's all very unusual to me as well. I've seen a number of chart changes, additions and updates over the years, but
never the number of
slight differences that exist with these 8 overlying procedures.
Originally Posted by TonyC
Unless there's a strong crosswind, I don't see how flying either procedure will place the airplane in a much different place. Back up to the feeder routes, even. Whether it's a 727 wandering left and right of a VOR signal, or a DC-10 going point to point with an INS, or and MD-11 with RNP of 2.0, I don't think you'll see much variation from what you see today. We're all trying to get from one point to the next with whatever tools we have on board.
These types of procedures are supposed to
reduce workload and help pilots and ATC by reducing the frequency congestion, as well as provide standardized routings in/out of the Terminal area. If I have to
guess or
ask each aircraft which STAR Procedure he's flying, or if I fall back into the habit of issing a heading at the "pivot point" and then relaying this information to the next sector -- then I've negated some of the positive benefits of implementing these new RNAV STAR Procedures.
Originally Posted by TonyC
Now, that's just my take on it from the perspective of having looked at the procedure on paper. Give us a chance to fly it and I might see something different.
As usual, thanks for your input. I'll post anything unsual from the ATC side.
Take care,
MEM_ATC