"Amendments" to clearence while enroute

[SIUav8er]

I have flown the same route repeatedly (KSAC-KRAL for example) and am very familiar with the clearence given for both directions, so I will file what I always get.

My question is why....
1. they dont just clear me "as filed"
2. while enroute, I recieve an "amended" clearence (usually when checking in with another controlling agency) and the "new" clearence is exactly the same as what I was already cleared to AND the same as what I filed!

is this normal?


I've never been able to figure out why this happens!

 

[daveatc]

A couple really simple things are probably happening.

1) You may get the exact route you filed for. However, if the computer kicks us out your flight plan with the little ++ on the strip indicating a change, we have to read the route. Since there's no way to know what you filed for, we read what we get.

2) As odd as it sounds, and I doubt this one, maybe it's their tower policy.

3) KSAC is a contract tower, not an FAA-manned tower. They might not have a FDIO that gives them flight plans automatically, so they might have to call NORCAL APCH directly to get your flight plan and the controller reading the clearance to KSAC will just read it full route instead of as filed, for the same reasons as 1 & 2. The Controller at KSAC has no idea what the computer kicked out, since they might not have a computer, so they just read it as it was read to them. We had that when I worked in Florida, and we had to get all the flight plans from Miami Apch. When I would read the clearance to the pilot and they did their readback, they would say "cleared to so-and-so airport as filed." Happened at least once a day.

4) When you're flying, each sector that you're going through gets a copy of your flight plan when you're approaching handoff into their sector. While you're traversing that airspace, the computer may recalculate your estimated time at a fix or at your destination and it will kick out another strip to the controllers. The way flight plans are coded, it may look like a change, but not actually be a change. The only thing that changed was your fix estimate. However, they might read it anyways.

The NAS has its little quirks which make it fun to deal with!

 

[SIUav8er]

Interesting... Thank you!