TEC Routes

[Mark Hargrove]

I need two points of clarification about TEC routes:

-- when there is more than one route for the aircraft type serving the same destination area, does it matter which one you select? (I can't ask the direct question I want to ask without creating a "spoiler" for the I-08 rating).

-- what does the altitude code in the preferred route database mean? Is it the mandatory altitude, or the minimum altitude, or something else? If it is the mandatory altitude then there is a disconnect between the I-08 transcript and the NFDC preferred route database (again, I can't ask the direct question I'd like to ask without creating another "spoiler").

Thanks!

-M.

[Peter Grey]

There shouldn't be more then 1 route for a given pairing and aircraft type. Note however that some routes are airport configuration dependent (normally the configurations at LAX, SNA, and SAN affect this). You can see this with notes like LAXE (LAX East) or SNAS (SNA South). As a rule LAX is west (LAXW), SAN is West (SANW) and SNA is South (SNAS).

Altitudes listed are mandatory. Note that altitudes can be type specific, so P50Q40 means type P flies at 5000 while type Q flies at 4000. If your type doesn't match the type in the transcript this can cause a disconnect.

[Steven Winslow]

But there are instances where more than one preferred route is available. See the screenshot below:

[Mark Hargrove]

There shouldn't be more then 1 route for a given pairing and aircraft type. Note however that some routes are airport configuration dependent (normally the configurations at LAX, SNA, and SAN affect this). You can see this with notes like LAXE (LAX East) or SNAS (SNA South). As a rule LAX is west (LAXW), SAN is West (SANW) and SNA is South (SNAS).

Hmm. Can you expand on what you mean by "airport configuration specific"? So the "rule" for LAX being "west" means what? What does it mean if I see LAXE rather than just LAX?

Altitudes listed are mandatory. Note that altitudes can be type specific, so P50Q40 means type P flies at 5000 while type Q flies at 4000. If your type doesn't match the type in the transcript this can cause a disconnect.

OK, got it -- thanks!

[Alex Stjepanovic]

There shouldn't be more then 1 route for a given pairing and aircraft type. Note however that some routes are airport configuration dependent (normally the configurations at LAX, SNA, and SAN affect this). You can see this with notes like LAXE (LAX East) or SNAS (SNA South). As a rule LAX is west (LAXW), SAN is West (SANW) and SNA is South (SNAS).

Hmm. Can you expand on what you mean by "airport configuration specific"? So the "rule" for LAX being "west" means what? What does it mean if I see LAXE rather than just LAX?

Airport configuration. Departing/arriving one set of runways or another, one direction or another, one time of day or another etc. When these change, depending on the complexity of airspace around such an airport, so do the traffic flows, which affects the route assignments.

Unless the airspace is super simple, one couldn't expect to have the same routes all the time, while still coming and going into an airport every which way.

The "rule", simply means that that's the common config of the airport. You don't see these places switch much.

[Peter Grey]

Based on your screenshot there are 5 possible routes from SBA to SAN, from top to bottom here is how to read which one to use.

Route 1 (SBAN30), This is for P and Q aircraft only (based on there being no published altitude for J and M), and is for use when KSAN is landing East (See SANE in the area section).

Route 2 (SBAN31), same as route 1 but for J and M type aircraft.

Route 3 (SBAN29), for J and M again, but with no notes on SANE or LAXE, the assumption is that SAN and LAX are West (which is the normal situation).

Route 4, (SBAN28), for P and Q and with LAX East (LAXE)

Route 5, (SBA27), for P and Q with no notes on SANE or LAXE, therefore assuming LAX and SAN are West.

The configuration notes tell you what to do based on the weather at certain airports along your route. Because of the amount of aircraft that land at LAX, SNA, and SAN when they change the runway in use it affects more then just aircraft landing at those airports. To account for this a significant number of TEC routes depend on which runway these airports are using.

90+% of the time LAX is using runways 24 and 25, this is the "West" configuration and is default.
The remaining 10% of the time LAX is using 6 and 7, this is the "East" configuration. Routes that have a note of LAXE are only to be used when these runways are in use at LAX. LAXW is generally not noted and is assumed (per the introduction to TEC routes in the A/FD). If no routes specify configuration then it does not matter what runway LAX is using.

In a similar fashion 90+% of the time SAN uses runway 27 (West) as opposed to 9 (East), and SNA uses runway 19s (South) as opposed to the 1s (North).

To keep it simple you can ignore routes that say SANE, LAXE, and SNAN. However for the rare case that those runways are in use you can expect ATC to change your route.

[Mark Hargrove]

Outstanding explanation -- thank you!

[Steven Winslow]

Peter, thanks for that explanation! Awesome!