Communication Breakdown; Confusion
ATC Issue All Types
Human Factors; Procedure
I submit this [report] regarding Pre Departure Clearances to give some suggestions in making the Pre Departure Clearance easier to understand; especially when receiving a route change; so that we can continue to reduce errors that are occurring related to PDC's.  Our PDC clearances come through the acars and then print in a fashion similar to this:PDC [ACR and Flight number]  ABCD  KLASB737/L  P1235161   380KLAS BTY LKV BTG [STAR]3. /.[DEST]CLEARED SUNST3 DEPCLIMB VIA SID EXCEPT MAINTAIN 190CALL 121.67 WITH GATE OR LOCATION WHEN READY TO TAXIACARS ENDNow all of the information that we need is here; however; the information is choppy and out of order [compared to a] normal clearance received via vhf radio and can include additional information that is unnecessary to the clearance from the pilots point of view.Most flight instructors and teachers are familiar with the law of primacy stating that 'what is learned first; is learned best'.  In keeping this in mind we should consider that most; if not all; pilots spend most of their formative years as IFR pilots receiving their clearance via vhf radio.  In doing that it is safe to say that the format which we receive our pre departure clearance over the radio is the best learned.  This should lead us into wanting our PDC via acars to mirror that process.  For example here is a IFR clearance over the radio:  '[ACR Flight number] you are cleared to the [destination] airport via the Sunset 3 departure BTY transition then as filed.  Climb via the sid except maintain FL190. Departure frequency is 125.4 squawk [XXXX].'  Comparing this clearance to the PDC received through ACARS and one can see the unorganized and confusing format of acars PDC.  To make matters worse in the event of a route change on ACARS sometimes; but not always; we will have two routes published one in between (-) symbols to signify the change while the filed route is published below.  How does this differ from a verbal clearance[?] ATC would not read us both cleared and filed routes we would only be read our cleared routing.  Sure we have added ATTENTION ROUTE CHANGE to possibly help us look for a change but even with this the pilots can inadvertently misunderstand the clearance.  The simple answer here is to always verify [with ATC] if we have a question but it doesn't address the actual problem which is a poorly presented clearance to the pilots via ACARS PDC.  The format in which we receive an IFR clearance over vhf radio should be the same as the way we are receiving our clearance via acars PDC.  In an effort to continue to eliminate errors can we [...] submit strong input to the FAA to push for these changes to help us in threat/error management.  An acars PDC that looks like this: [Company] Cleared via Sunset 3 dep BTY transition then As Filed (or route if different from filed) Climb via the SID except maintain FL190...Dep Freq  124.5 Squawk [XXXX] Rmrks: Maintain 250kts or less till advised.'As you can see in this acars PDC message we have received all of the necessary information in an organized and recognizable format (same as receiving vhf radio) while eliminat[ing] excess information not needed [by] the pilot and eliminating any confusion as to which route applies in the event of a route change.  I truly believe these changes would drastically reduce errors by pilots in relation to PDC's as noted in our LOSA data and [company safety] program; not only at our airline but others as well.
A B737 First Officer addressed the decades old problem of misinterpreted PDC clearances and subsequent deviations due to their ambiguous and confusing formatting.  He further provided a simple; on point suggestion he believes would eliminate the majority of such errors and make air travel safer.