Narrative:

Cleared via pdcs printed clearance for the ROCKY5 departure. Verbiage in SID says; 'climb runway heading 227 degrees until ivzk D2.6...then fly heading assigned 227 or 212 degrees. Expect radar vectors.' we briefed the SID and from our reading; 'fly assigned heading' meant that heading in the SID was assigned. Apparently; that really means; 'fly heading that will be assigned by tower.' but it doesn't say that; even though it can (and did) mean that to someone reading it prior to takeoff. When the tower controller cleared us for takeoff and said; 'fly runway heading;' that sounded like confirmation of the SID as we briefed it; which starts out with; 'fly runway heading.' had he said; 'fly heading 227;' he would have fulfilled the SID 'assigned heading' stipulation regarding headings after takeoff. It doesn't say; 'fly runway heading or assigned heading 212 or 227.' so we assumed we were on the SID since he hadn't specified anything other than what's on the first line of the SID. I can't recall many SID's where you are to fly an either/or heading without somewhere including an indication that the heading will be assigned by tower. In this case; why the two headings in the SID if it's a tower assignment in all cases? Why the verbiage; 'fly assigned heading 212 or 227;' which is confusing without the crucial information; as assigned by tower? Speaking with the TRACON supervisor later; he said this ambiguity is a constant source of confusion with flts out of there. He said pilot always ask; 'do you want us to fly the SID or your heading?' I can see why this is constant source of confusion; because without an indication that; 'tower will assign a heading;' in which case the 212 or 227 degree heading doesn't need to be in the SID instructions -- there are several ways to read this procedure; not all of which conform to the tower's intent.

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Original NASA ASRS Text

Title: AN MD80 CREW DEPARTING ON THE IND ROCKY5 QUESTION THE AMBIGUOUS WORDING ABOUT THE INITIAL DEP HDG OF 227 OR 212 DEGS.

Narrative: CLRED VIA PDCS PRINTED CLRNC FOR THE ROCKY5 DEP. VERBIAGE IN SID SAYS; 'CLB RWY HDG 227 DEGS UNTIL IVZK D2.6...THEN FLY HDG ASSIGNED 227 OR 212 DEGS. EXPECT RADAR VECTORS.' WE BRIEFED THE SID AND FROM OUR READING; 'FLY ASSIGNED HDG' MEANT THAT HDG IN THE SID WAS ASSIGNED. APPARENTLY; THAT REALLY MEANS; 'FLY HDG THAT WILL BE ASSIGNED BY TWR.' BUT IT DOESN'T SAY THAT; EVEN THOUGH IT CAN (AND DID) MEAN THAT TO SOMEONE READING IT PRIOR TO TKOF. WHEN THE TWR CTLR CLRED US FOR TKOF AND SAID; 'FLY RWY HDG;' THAT SOUNDED LIKE CONFIRMATION OF THE SID AS WE BRIEFED IT; WHICH STARTS OUT WITH; 'FLY RWY HDG.' HAD HE SAID; 'FLY HDG 227;' HE WOULD HAVE FULFILLED THE SID 'ASSIGNED HDG' STIPULATION REGARDING HDGS AFTER TKOF. IT DOESN'T SAY; 'FLY RWY HDG OR ASSIGNED HDG 212 OR 227.' SO WE ASSUMED WE WERE ON THE SID SINCE HE HADN'T SPECIFIED ANYTHING OTHER THAN WHAT'S ON THE FIRST LINE OF THE SID. I CAN'T RECALL MANY SID'S WHERE YOU ARE TO FLY AN EITHER/OR HDG WITHOUT SOMEWHERE INCLUDING AN INDICATION THAT THE HDG WILL BE ASSIGNED BY TWR. IN THIS CASE; WHY THE TWO HDGS IN THE SID IF IT'S A TWR ASSIGNMENT IN ALL CASES? WHY THE VERBIAGE; 'FLY ASSIGNED HDG 212 OR 227;' WHICH IS CONFUSING WITHOUT THE CRUCIAL INFO; AS ASSIGNED BY TWR? SPEAKING WITH THE TRACON SUPVR LATER; HE SAID THIS AMBIGUITY IS A CONSTANT SOURCE OF CONFUSION WITH FLTS OUT OF THERE. HE SAID PLT ALWAYS ASK; 'DO YOU WANT US TO FLY THE SID OR YOUR HDG?' I CAN SEE WHY THIS IS CONSTANT SOURCE OF CONFUSION; BECAUSE WITHOUT AN INDICATION THAT; 'TWR WILL ASSIGN A HDG;' IN WHICH CASE THE 212 OR 227 DEG HDG DOESN'T NEED TO BE IN THE SID INSTRUCTIONS -- THERE ARE SEVERAL WAYS TO READ THIS PROC; NOT ALL OF WHICH CONFORM TO THE TWR'S INTENT.

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