Narrative:

I feel better communication between the ATC and us would have helped. Callback conversation with reporter revealed the following information: the captain said that he earnestly attempted to inform the first officer about what the controller wanted, but that he failed. He felt that he should have been more direct and this analyst agreed. The captain did have a postflt discussion with the first officer concerning this incident and they both agreed that the controller's instructions were confusing. On this approach, you never cross over the dam on final to runway 17L since the dam is to the west of the approach to runway 18R. The flight crew was flying a saab-scania sf 340B aircraft and the first officer was a low time pilot who was still getting used to the aircraft. Supplemental information from acn 305321: approximately 5 mi northeast of the dfw airport, we were cleared for the visual approach runway 17L, land runway 13L (runway 17L closed), 'turn final over the dam.' we discussed the ambiguity of the latter part of the clearance. The only 2 dams in the immediate area were lake lewisville dam (which could not have been the one referred to, since it was north of our current position), and lake grapevine dam, which was due west of our position, but directly under the runway 18R final approach course. I concluded that the approach controller wanted us to turn left from our current heading of 290 degrees and proceed due west toward the dam, keeping our base to final square by turning abeam the dam. I explained this to the first officer, but he apparently didn't have the same picture as I did, and still had it in mind to proceed to a point over the dam before turning final (which is what the controller had actually said). By the time I discovered this and questioned him, we were passing through the runway 17L localizer, and a full 30 degree bank turn (from a 90 degree intercept) to the left still didn't prevent us from getting very close to the runway 18R approach course. We landed on runway 13L without incident and caused no actual traffic problem. Actions which could have prevented or lessened the problem: captain questioning ATC about the clearance. First officer asserting that he may not still be clear on what we were to do. Captain being quicker and more assertive when it became apparent that we might be overshooting the approach course into the dead space between the parallel approachs. Either stating clearly '30 degrees left bank, immediately!' or actually taking the yoke and doing it myself if any delay in response noted to lessen the proximity of the runway 18R parallel approach course.

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Original NASA ASRS Text

Title: PHRASEOLOGY. COCKPIT RESOURCE MGMNT. ACR IS IMPROPERLY TOLD TO FLY OVER A POINT NOT IN LINE WITH THE APCH RWY.

Narrative: I FEEL BETTER COM BTWN THE ATC AND US WOULD HAVE HELPED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE CAPT SAID THAT HE EARNESTLY ATTEMPTED TO INFORM THE FO ABOUT WHAT THE CTLR WANTED, BUT THAT HE FAILED. HE FELT THAT HE SHOULD HAVE BEEN MORE DIRECT AND THIS ANALYST AGREED. THE CAPT DID HAVE A POSTFLT DISCUSSION WITH THE FO CONCERNING THIS INCIDENT AND THEY BOTH AGREED THAT THE CTLR'S INSTRUCTIONS WERE CONFUSING. ON THIS APCH, YOU NEVER CROSS OVER THE DAM ON FINAL TO RWY 17L SINCE THE DAM IS TO THE W OF THE APCH TO RWY 18R. THE FLC WAS FLYING A SAAB-SCANIA SF 340B ACFT AND THE FO WAS A LOW TIME PLT WHO WAS STILL GETTING USED TO THE ACFT. SUPPLEMENTAL INFO FROM ACN 305321: APPROX 5 MI NE OF THE DFW ARPT, WE WERE CLRED FOR THE VISUAL APCH RWY 17L, LAND RWY 13L (RWY 17L CLOSED), 'TURN FINAL OVER THE DAM.' WE DISCUSSED THE AMBIGUITY OF THE LATTER PART OF THE CLRNC. THE ONLY 2 DAMS IN THE IMMEDIATE AREA WERE LAKE LEWISVILLE DAM (WHICH COULD NOT HAVE BEEN THE ONE REFERRED TO, SINCE IT WAS N OF OUR CURRENT POS), AND LAKE GRAPEVINE DAM, WHICH WAS DUE W OF OUR POS, BUT DIRECTLY UNDER THE RWY 18R FINAL APCH COURSE. I CONCLUDED THAT THE APCH CTLR WANTED US TO TURN L FROM OUR CURRENT HDG OF 290 DEGS AND PROCEED DUE W TOWARD THE DAM, KEEPING OUR BASE TO FINAL SQUARE BY TURNING ABEAM THE DAM. I EXPLAINED THIS TO THE FO, BUT HE APPARENTLY DIDN'T HAVE THE SAME PICTURE AS I DID, AND STILL HAD IT IN MIND TO PROCEED TO A POINT OVER THE DAM BEFORE TURNING FINAL (WHICH IS WHAT THE CTLR HAD ACTUALLY SAID). BY THE TIME I DISCOVERED THIS AND QUESTIONED HIM, WE WERE PASSING THROUGH THE RWY 17L LOC, AND A FULL 30 DEG BANK TURN (FROM A 90 DEG INTERCEPT) TO THE L STILL DIDN'T PREVENT US FROM GETTING VERY CLOSE TO THE RWY 18R APCH COURSE. WE LANDED ON RWY 13L WITHOUT INCIDENT AND CAUSED NO ACTUAL TFC PROB. ACTIONS WHICH COULD HAVE PREVENTED OR LESSENED THE PROB: CAPT QUESTIONING ATC ABOUT THE CLRNC. FO ASSERTING THAT HE MAY NOT STILL BE CLR ON WHAT WE WERE TO DO. CAPT BEING QUICKER AND MORE ASSERTIVE WHEN IT BECAME APPARENT THAT WE MIGHT BE OVERSHOOTING THE APCH COURSE INTO THE DEAD SPACE BTWN THE PARALLEL APCHS. EITHER STATING CLRLY '30 DEGS L BANK, IMMEDIATELY!' OR ACTUALLY TAKING THE YOKE AND DOING IT MYSELF IF ANY DELAY IN RESPONSE NOTED TO LESSEN THE PROX OF THE RWY 18R PARALLEL APCH COURSE.

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.