Star crossing restrictions on undefined points

[wrf2e 1]

Ok.  I did a search and found many useful threads, but none answered my exact question.  First, let me give an example of where I need help.

 

Flying into SAN on the BARET 4 arrival, there is a restriction that states "Expect to cross 24NM Northeast of the PGY Vortac at 12,000.  OK, I know how to do this if PGY was part of the route or if it were to give something like "Expect to cross 24 DME from the PGY vortac on the 45 degree radial at 12,000".  The problem is determining at which point along the Star is 24nm from PGY.

 

I know I could give it a best guess and manually aim for 12000 by tuning PGY and watching the DME but there has to be a more accurate and less involved way (especially on this already intense approach/landing) to load this in the FMC and use VNAV to hit this point....right?

 

 

 

Wesley Frost

[scandinavian13 5,192]

 

 

I know I could give it a best guess and manually aim for 12000 by tuning PGY and watching the DME but there has to be a more accurate and less involved way (especially on this already intense approach/landing) to load this in the FMC and use VNAV to hit this point....right?

 

If I'm remembering this one correctly, PGY isn't actually on the STAR, and they're just giving you a reference point.  I don't know SoCal TRACON very well, but I do know that - over here - we avoid giving instructions like that.  Apparently they do issue the instruction just as on the chart, according to one of my friends.

 

You could, however, join the 21st Century and save yourself all of that pain simply by filing a better STAR that utilizes RNAV instead ANAV (old school VOR-VOR-type stuff): the LYNDI.

 

Same exact STAR, just RNAV and no guesswork: http://airnav.com/depart?http://155.178.201.160/d-tpp/1410/00373LYNDI.PDF

 

Always pay attention to your options!  :wink:

[wrf2e 1]

Good call on filing the different STAR.  I did encounter this restriction with LAX CTR on VATSIM.  I should pay more attention to the options, as I usually file whatever PFPX gives me.  I am flying this route again now (ATC is not online) and I was able to plan before T/O by adding the ring around PGY at 25nm and guessing a distance from the IFHEI way point and adding a custom way point with the altitude restriction.  It is only about 3.5 nm before IFHEI...I guess the FAA in their infinite wisdom couldn't have just said "cross IFHEI at 11000. 

[scandinavian13 5,192]

 

 

I should pay more attention to the options, as I usually file whatever PFPX gives me.

 

Yeah - always be wary of things a computer hands you.  At least double check.

 

 

 

I guess the FAA in their infinite wisdom couldn't have just said "cross IFHEI at 11000. 

 

It probably has roots in an older procedure, perhaps even with different legs and fixes, but the instruction was familiar with crews, so they just left it.  The TERPS teams are usually pretty good at coming up with more straightforward procedures.  Crossing points are usually not depicted on scopes unless they're associated with fixes, but different facilities have different engineers, who create and offer different maps, so it very well may be.  Still, it's a little arcane, outdated, and has an associated higher workload to ensuring compliance on both sides: pilot and controller (even if the crossing restriction was noted on one of the maps, they usually don't have those maps on in order to reduce clutter, so they have to eyeball it, whereas fixes are shown on the base maps as Xs).

 

Since they have the RNAV version which omits that instruction entirely, we can't fault them too much.  The ANAV versions must remain, though, because there are still aircraft out there without RNAV capabilities.  This is something I often laugh at, since I know of a 1945-built DC3 with RNAV capability, but we also have to remember that equipage is not inexpensive, unfortunately.

[g_precentralis 191]

You can add restriction to SALTN or CUMBA, depending from which side you are coming. It will not give you continuous descend, but you will comply with the instruction.

 

You can do it manually too, just draw 25nm arc around PGY, and set vertical speed so descend arc at ND is touching PGY 25nm arc.

 

Even more manually, if you are coming from northeast, you can assume you are flying directly to VORTAC, so you can use rate of closure and DME to calculate your descend really quick.

[downscc 1,327]

Navigraph should encode that altitude restriction, but my guess is they don't because it is not included in the FAA raw data. When I was encoding sidstars, I did do the math and define a waypoint at PGY D25 on the route segment at location LATLON N 32 52.202 W 116 35.537

[scandinavian13 5,192]

 

 

but my guess is they don't because it is not included in the FAA raw data

 

Bingo.  Expected instructions shouldn't be in there.  Only hard altitudes should be, though I have seen a mix in the Navigraph data...