B737-300 first officer misinterprets a 'revised' segment portion of a pre departure clearance cleara...

Attributes
ACN	775829
Time
Date	200802
Place
Locale Reference	atc facility : zny.artcc
State Reference	NY
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 263 flight time type : 750
ASRS Report	775829
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	aircraft equipment problem : critical non adherence : far non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : issued advisory flight crew : returned to intended or assigned course
Supplementary
Problem Areas	FAA Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

We received pre departure clearance to buf. The pre departure clearance message modified the routing using the '-' symbol. Within the '-' modification symbols; it stated '...J220 vallo -.' in my haste; I incorrectly interpreted this modification to indicate a clearance to proceed direct buf VOR (off airways) after reaching vallo intersection. The correct interpretation should have been to continue on J220 airway en route buf instead of proceeding direct. Shortly after departing vallo en route direct buf; ATC told us to turn 10 degrees right since we were off course. We clarified our clearance; corrected the FMC programming; and continued uneventfully to buf. ATC advised us that no further action was necessary on our part. Pre departure clearance's should not show a modification when none exists. In other words; we were cleared exactly as filed; but our pre departure clearance showed a modification using the '-' symbol. I suggest reserving the modification symbols for use only when an actual modification to the filed route exists.

Original NASA ASRS Text

Title: B737-300 FO MISINTERPRETS A 'REVISED' SEGMENT PORTION OF A PDC CLRNC AS A REVISION OF THE ROUTE ... WHICH IT ISN'T.

Narrative: WE RECEIVED PDC TO BUF. THE PDC MESSAGE MODIFIED THE ROUTING USING THE '-' SYMBOL. WITHIN THE '-' MODIFICATION SYMBOLS; IT STATED '...J220 VALLO -.' IN MY HASTE; I INCORRECTLY INTERPED THIS MODIFICATION TO INDICATE A CLRNC TO PROCEED DIRECT BUF VOR (OFF AIRWAYS) AFTER REACHING VALLO INTXN. THE CORRECT INTERP SHOULD HAVE BEEN TO CONTINUE ON J220 AIRWAY ENRTE BUF INSTEAD OF PROCEEDING DIRECT. SHORTLY AFTER DEPARTING VALLO ENRTE DIRECT BUF; ATC TOLD US TO TURN 10 DEGS R SINCE WE WERE OFF COURSE. WE CLARIFIED OUR CLRNC; CORRECTED THE FMC PROGRAMMING; AND CONTINUED UNEVENTFULLY TO BUF. ATC ADVISED US THAT NO FURTHER ACTION WAS NECESSARY ON OUR PART. PDC'S SHOULD NOT SHOW A MODIFICATION WHEN NONE EXISTS. IN OTHER WORDS; WE WERE CLRED EXACTLY AS FILED; BUT OUR PDC SHOWED A MODIFICATION USING THE '-' SYMBOL. I SUGGEST RESERVING THE MODIFICATION SYMBOLS FOR USE ONLY WHEN AN ACTUAL MODIFICATION TO THE FILED RTE EXISTS.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

B737-300 first officer misinterprets a 'revised' segment portion of a pre departure clearance clearance as a revision of the route ... Which it isn't.