S80 flight crew blames sea summa SID chart depiction as reason for course deviation.

Attributes
ACN	559244
Time
Date	200209
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : sea.vortac
State Reference	WA
Aircraft 1
Controlling Facilities	tracon : s46.tracon
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : summa 6
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	559244
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	Chart Or Publication Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Sea departure plate is drawn so olm looks only about 25% closer to summa than is bke VOR. Bke is in fact about 400% further away. Without a detailed read of this plate, this is easily overlooked. If bke is tuned in to identify the turn at summa instead of olm, the crew is likely to blow through the intersection and miss the turn toward bke. I know we did, and I suspect it happens frequently because ATC caught us fairly quickly.

Original NASA ASRS Text

Title: S80 FLC BLAMES SEA SUMMA SID CHART DEPICTION AS REASON FOR COURSE DEV.

Narrative: SEA DEP PLATE IS DRAWN SO OLM LOOKS ONLY ABOUT 25% CLOSER TO SUMMA THAN IS BKE VOR. BKE IS IN FACT ABOUT 400% FURTHER AWAY. WITHOUT A DETAILED READ OF THIS PLATE, THIS IS EASILY OVERLOOKED. IF BKE IS TUNED IN TO IDENT THE TURN AT SUMMA INSTEAD OF OLM, THE CREW IS LIKELY TO BLOW THROUGH THE INTXN AND MISS THE TURN TOWARD BKE. I KNOW WE DID, AND I SUSPECT IT HAPPENS FREQUENTLY BECAUSE ATC CAUGHT US FAIRLY QUICKLY.

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.