Full Route Clearances and Digital PDC

[Pilot Hopeful]

I have noticed when ATC issues reroutes with full route clearances (e.g., weather avoidance) at airports having digital pre-departure clearance (PDC) service that the controllers generally resort to issuing the clearance verbally. This arrangement puzzles me because the time required to read multiple clearances greatly increases frequency congestion; it also increases the probability of pilot error in hearing, transcribing, or entering the amended routing. What is the rationale behind this solution? Although not all aircraft have PDC capabilities, it seems less-than-ideal to use the system only for routine "as filed" clearances. In fact, it would seem that the PDC system would be most beneficial for providing timely, accurate reroutes when the controller radio workload escalates.

One potential issue could be that ATC needs to verify that pilots have the correct clearance. If an amendment to is made after initial PDC retrieval, then ATC would need to ensure the new routing makes it to the pilots prior to takeoff. Even so, a simple verification protocol between a local controller and pilots before departure need not be as time consuming and cumbersome as the current one.

 

[jdlilfan]

I agree. I think it has something to do with the clearances coming from the ARTCC data computers rather than the local tower/tracon facilities. The controllers at the local facilities appear to just send out what's in the computer system rather than have the ability to manually edit each PDC. Perhaps a limit due to like of ADS capability?

In places abroad with ADS capability you do see the individual tailored clearances such as a change in the filed SID or regional routing ie. Europe, Hong Kong, etc....

 

[ajmezz]

I worked at ARINC Direct for 3 years and from the guys who had PDC we noticed issues all the time. It basically breaks down to if you get a clearance from xxx airport, you can't get another one within 24 hours at that same airport. Also, if you make any changes to the clearance (ptime update usually caught most of our guys) once its in centers computers, then it voids out the option to get pdc. Now the system could work completely different with air carriers, but those were my experiences with GA.

 

[BWER]

I do not know the technical side behind it but any amendment made to a FP in PDC forces that FP out of the system, this includes receiving a duplicate FP. A couple years back we were coming up on ERAM and we were doing our first set of runs on mid shifts. We switched over to ERAM after all the purple tail cargo arrivals were safely unloading their boxes on the ground and had their OPS send their outbound FP's. Everything was going good until we had to fall back to HOST, well then PDC got dupes on 150+ flight plans and dumped every one of em.

When I left work that morning at 6:30 the purple tails were still leaving the ground, which normally wraps up around 5. I talked to some folks that worked the tower that night a few months after that...and they were hating life the moment PDC took a dump.

 

[Jetfreq]

I've worked at LIT and SDF (currently). When a reroute comes through the PDC system, our only option is to dump it. We are unable to issue it via PDC. Believe me, we'd prefer to be able to PDC it when we are busy, but for us it is not an option.

 

[Mdriver]

I have found that when i file from a PDC supported facility ,if the clearance is amended or if in the original filing i didnt include a departure the i will not be able to pick up PDC and will have to get verbal and many times its a full route clearance