Track deviation by air carrier light transport results in potential conflict airborne.

Attributes
ACN	94030
Time
Date	198809
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : sfo
State Reference	CA
Altitude	msl bound lower : 10000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : oak
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	departure other enroute : on vectors enroute airway : v27 enroute airway : v199
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 240 flight time total : 5000 flight time type : 350
ASRS Report	94030
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Deviation Inter Facility Coordination Failure

Narrative:

Received our clearance from sfo clearance delivery. It was as follows. Cleared to acv, left turn after departure 350 degree stins as filed climb and maintain 3000', expect FL220 in 3 min, departure on 135.1, squawk. Our as filed route (per our company paperwork and later checked by oak center) is as follows. Sfo stins EN1 V27 fot acv. Bay approach climbed us on the 350 degree heading for a while, then turned us to 290 degree, then turned us to 240 degree to intercept the sfo 287 degree right stins intersection as filed and contact oak center. As we approached stins, I double checked my filed route sheet to make sure we were direct eni after stins. About 10 mi later, oak center questioned our routing. I thought about asking oak center if we were to go direct eni after stins but did not because the clearance and filed route was clear, ATC often gets perturbed when asked such questions (although this has never stopped me before). I had the feeling that stins direct eni was not what oak center was expecting, but the whole routing (although the clearance was normal) was strange. We never intercept the sfo 287R or get to stins, we are always vectored to eni earlier. This did cause oak center to reroute other aircraft. Callback conversation with reporter revealed the following. Conversation revealed that in conversation with ARTCC, the center was expecting the flight to depart stins on V199 instead of direct EMI which is essentially V27. PF wondered when flight actually vectored to stins if something different was expected as normally, although filed that way they get vectored direct EMI before getting near stins. Confirmed way flight flew was what was on file in center but when clearance issued by center, it was supposed to indicate V199. Tapes were to be checked to see where breakdown was if error was center or sfo clearance delivery or TRACON that was supposed to transmit the change.

Original NASA ASRS Text

Title: TRACK DEVIATION BY ACR LTT RESULTS IN POTENTIAL CONFLICT AIRBORNE.

Narrative: RECEIVED OUR CLRNC FROM SFO CLRNC DELIVERY. IT WAS AS FOLLOWS. CLRED TO ACV, LEFT TURN AFTER DEP 350 DEG STINS AS FILED CLB AND MAINTAIN 3000', EXPECT FL220 IN 3 MIN, DEP ON 135.1, SQUAWK. OUR AS FILED ROUTE (PER OUR COMPANY PAPERWORK AND LATER CHKED BY OAK CENTER) IS AS FOLLOWS. SFO STINS EN1 V27 FOT ACV. BAY APCH CLBED US ON THE 350 DEG HDG FOR A WHILE, THEN TURNED US TO 290 DEG, THEN TURNED US TO 240 DEG TO INTERCEPT THE SFO 287 DEG R STINS INTXN AS FILED AND CONTACT OAK CENTER. AS WE APCHED STINS, I DOUBLE CHKED MY FILED ROUTE SHEET TO MAKE SURE WE WERE DIRECT ENI AFTER STINS. ABOUT 10 MI LATER, OAK CENTER QUESTIONED OUR ROUTING. I THOUGHT ABOUT ASKING OAK CENTER IF WE WERE TO GO DIRECT ENI AFTER STINS BUT DID NOT BECAUSE THE CLRNC AND FILED ROUTE WAS CLR, ATC OFTEN GETS PERTURBED WHEN ASKED SUCH QUESTIONS (ALTHOUGH THIS HAS NEVER STOPPED ME BEFORE). I HAD THE FEELING THAT STINS DIRECT ENI WAS NOT WHAT OAK CENTER WAS EXPECTING, BUT THE WHOLE ROUTING (ALTHOUGH THE CLRNC WAS NORMAL) WAS STRANGE. WE NEVER INTERCEPT THE SFO 287R OR GET TO STINS, WE ARE ALWAYS VECTORED TO ENI EARLIER. THIS DID CAUSE OAK CENTER TO REROUTE OTHER ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING. CONVERSATION REVEALED THAT IN CONVERSATION WITH ARTCC, THE CENTER WAS EXPECTING THE FLT TO DEPART STINS ON V199 INSTEAD OF DIRECT EMI WHICH IS ESSENTIALLY V27. PF WONDERED WHEN FLT ACTUALLY VECTORED TO STINS IF SOMETHING DIFFERENT WAS EXPECTED AS NORMALLY, ALTHOUGH FILED THAT WAY THEY GET VECTORED DIRECT EMI BEFORE GETTING NEAR STINS. CONFIRMED WAY FLT FLEW WAS WHAT WAS ON FILE IN CENTER BUT WHEN CLRNC ISSUED BY CENTER, IT WAS SUPPOSED TO INDICATE V199. TAPES WERE TO BE CHKED TO SEE WHERE BREAKDOWN WAS IF ERROR WAS CENTER OR SFO CLRNC DELIVERY OR TRACON THAT WAS SUPPOSED TO XMIT THE CHANGE.

Data retrieved from NASA's ASRS site as of August 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.