Heading track route deviation as flight crew misinterprets clearance.

Attributes
ACN	180218
Time
Date	199106
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sea
State Reference	WA
Altitude	msl bound lower : 4000 msl bound upper : 9000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sea tower : ord
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Route In Use	departure other departure sid : sid enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 5000 flight time type : 750
ASRS Report	180218
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 140 flight time total : 3000 flight time type : 250
ASRS Report	180596
Events
Anomaly	non adherence : published procedure non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On june 1991, I was PIC of flight sea to ord. We departed sea from runway 34L at approximately aa:30 PDT. Copilot was flying. On takeoff roll or at brake release, we confirmed with our takeoff clearance acknowledgement to sea tower 'runway heading'. After flying runway heading for about 17 DME north of sea (116.8) we were given a turn to 100 degree to intercept J90 from southeast, and asked if we had been given the 'mountain two' departure. I looked at our 'ACARS' flight clearance printout, which, on the release line, read 'sea-J90-MLS-J204.1. Ord' and I replied 'negative'. Upon completion of the turn, as time and conditions permitted, I examined the ACARS clearance more closely, and found the 'mountain two' departure listed 3 lines below what I had seen and considered to be our clearance copy of ACARS and the mountain 2 clrncs are included. I then told departure that we had been cleared via the mountain two. However, it appears as if the printout was non-standard in format, since the SID was not included as part of our viable route of flight. I would have expected the clearance line from ACARS to read: 'maintain two vectors J90-MLS-J204.1. Ord' in order to positively identify the SID as an integral part of our flight release.

Original NASA ASRS Text

Title: HEADING TRACK ROUTE DEVIATION AS FLT CREW MISINTERPRETS CLRNC.

Narrative: ON JUNE 1991, I WAS PIC OF FLT SEA TO ORD. WE DEPARTED SEA FROM RWY 34L AT APPROX AA:30 PDT. COPLT WAS FLYING. ON TKOF ROLL OR AT BRAKE RELEASE, WE CONFIRMED WITH OUR TKOF CLRNC ACKNOWLEDGEMENT TO SEA TWR 'RWY HDG'. AFTER FLYING RWY HDG FOR ABOUT 17 DME N OF SEA (116.8) WE WERE GIVEN A TURN TO 100 DEG TO INTERCEPT J90 FROM SE, AND ASKED IF WE HAD BEEN GIVEN THE 'MOUNTAIN TWO' DEP. I LOOKED AT OUR 'ACARS' FLT CLRNC PRINTOUT, WHICH, ON THE RELEASE LINE, READ 'SEA-J90-MLS-J204.1. ORD' AND I REPLIED 'NEGATIVE'. UPON COMPLETION OF THE TURN, AS TIME AND CONDITIONS PERMITTED, I EXAMINED THE ACARS CLRNC MORE CLOSELY, AND FOUND THE 'MOUNTAIN TWO' DEP LISTED 3 LINES BELOW WHAT I HAD SEEN AND CONSIDERED TO BE OUR CLRNC COPY OF ACARS AND THE MOUNTAIN 2 CLRNCS ARE INCLUDED. I THEN TOLD DEP THAT WE HAD BEEN CLRED VIA THE MOUNTAIN TWO. HOWEVER, IT APPEARS AS IF THE PRINTOUT WAS NON-STANDARD IN FORMAT, SINCE THE SID WAS NOT INCLUDED AS PART OF OUR VIABLE RTE OF FLT. I WOULD HAVE EXPECTED THE CLRNC LINE FROM ACARS TO READ: 'MAINTAIN TWO VECTORS J90-MLS-J204.1. ORD' IN ORDER TO POSITIVELY IDENT THE SID AS AN INTEGRAL PART OF OUR FLT RELEASE.

Data retrieved from NASA's ASRS site as of July 2007 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.