Narrative:

We were cleared by approach control for a visual approach to runway 21L at dtw, behind another aircraft which we had in sight, but was no traffic factor for us. Switching to tower frequency, the local controller told us to slow to our final approach speed. We continued to slow up and configure for the approach, but the controller apparently wanted still more spacing, so he asked for an s-turn to the left. We complied with his request, but because of our close proximity to the airport, the turn required a steeper than usual turn on final to realign with the runway. This generated a complaint, from a passenger who was apparently frightened and said he felt that we were too close to the ground for that kind of maneuver. (We did not get realigned with runway centerline until approximately 300-400 ft AGL). Although there was never a doubt in my own mind about the safety of completing the maneuver, it was somewhat out of the ordinary, and I obviously compromised passenger comfort to accommodate the controller and to prevent a go around. In retrospect, I believe that if presented with a similar situation again, I would either refuse the s-turn or perhaps initiate a go around if I felt it was beginning to look unusual to my passengers. Our company has no specific guidelines on the initiation or completion of s-turns. West do have a policy that the final approach will be stable below 1000 ft AGL, but I have always related that to speed and flap confign, and hadn't thought of it specifically with regard to the s-turn. I don't know if there are any controller guidelines that specifically relate to s-turns, but if there are not, perhaps some might be in order. I feel that we were issued this request too late in the approach. On a broader spectrum, it appears to me that with the increasing volume of traffic at major airports throughout the country, the s-turn is being used with increasing frequency as a technique to adjust the spacing of arriving aircraft. Instead of being something seen or done only occasionally, it has now become commonplace, and seems to be receiving more acceptance as a routine procedure. (As we were taxiing in from the approach described above, a pilot on final asked the tower for a 'turn out to the west' to increase spacing). As traffic volume continues to rise, there will be increased pressure on both pilots and controllers to 'move the metal'. I feel there is potential for compromising both comfort and safety in the increasing use of the s-turn, and I for one am going to be more cautious about initiating or accepting this maneuver.

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Original NASA ASRS Text

Title: CAPT FLYING MLG MADE S TURNS TO ACCOMODATE REQUEST FROM TWR CTLR TO ALLOW A DEP. PAX COMPLAINT AS BEING UNSAFE.

Narrative: WE WERE CLRED BY APCH CTL FOR A VISUAL APCH TO RWY 21L AT DTW, BEHIND ANOTHER ACFT WHICH WE HAD IN SIGHT, BUT WAS NO TFC FACTOR FOR US. SWITCHING TO TWR FREQ, THE LCL CTLR TOLD US TO SLOW TO OUR FINAL APCH SPD. WE CONTINUED TO SLOW UP AND CONFIGURE FOR THE APCH, BUT THE CTLR APPARENTLY WANTED STILL MORE SPACING, SO HE ASKED FOR AN S-TURN TO THE L. WE COMPLIED WITH HIS REQUEST, BUT BECAUSE OF OUR CLOSE PROX TO THE ARPT, THE TURN REQUIRED A STEEPER THAN USUAL TURN ON FINAL TO REALIGN WITH THE RWY. THIS GENERATED A COMPLAINT, FROM A PAX WHO WAS APPARENTLY FRIGHTENED AND SAID HE FELT THAT WE WERE TOO CLOSE TO THE GND FOR THAT KIND OF MANEUVER. (WE DID NOT GET REALIGNED WITH RWY CENTERLINE UNTIL APPROX 300-400 FT AGL). ALTHOUGH THERE WAS NEVER A DOUBT IN MY OWN MIND ABOUT THE SAFETY OF COMPLETING THE MANEUVER, IT WAS SOMEWHAT OUT OF THE ORDINARY, AND I OBVIOUSLY COMPROMISED PAX COMFORT TO ACCOMMODATE THE CTLR AND TO PREVENT A GAR. IN RETROSPECT, I BELIEVE THAT IF PRESENTED WITH A SIMILAR SITUATION AGAIN, I WOULD EITHER REFUSE THE S-TURN OR PERHAPS INITIATE A GAR IF I FELT IT WAS BEGINNING TO LOOK UNUSUAL TO MY PAXS. OUR COMPANY HAS NO SPECIFIC GUIDELINES ON THE INITIATION OR COMPLETION OF S-TURNS. W DO HAVE A POLICY THAT THE FINAL APCH WILL BE STABLE BELOW 1000 FT AGL, BUT I HAVE ALWAYS RELATED THAT TO SPD AND FLAP CONFIGN, AND HADN'T THOUGHT OF IT SPECIFICALLY WITH REGARD TO THE S-TURN. I DON'T KNOW IF THERE ARE ANY CTLR GUIDELINES THAT SPECIFICALLY RELATE TO S-TURNS, BUT IF THERE ARE NOT, PERHAPS SOME MIGHT BE IN ORDER. I FEEL THAT WE WERE ISSUED THIS REQUEST TOO LATE IN THE APCH. ON A BROADER SPECTRUM, IT APPEARS TO ME THAT WITH THE INCREASING VOLUME OF TFC AT MAJOR ARPTS THROUGHOUT THE COUNTRY, THE S-TURN IS BEING USED WITH INCREASING FREQ AS A TECHNIQUE TO ADJUST THE SPACING OF ARRIVING ACFT. INSTEAD OF BEING SOMETHING SEEN OR DONE ONLY OCCASIONALLY, IT HAS NOW BECOME COMMONPLACE, AND SEEMS TO BE RECEIVING MORE ACCEPTANCE AS A ROUTINE PROC. (AS WE WERE TAXIING IN FROM THE APCH DESCRIBED ABOVE, A PLT ON FINAL ASKED THE TWR FOR A 'TURN OUT TO THE W' TO INCREASE SPACING). AS TFC VOLUME CONTINUES TO RISE, THERE WILL BE INCREASED PRESSURE ON BOTH PLTS AND CTLRS TO 'MOVE THE METAL'. I FEEL THERE IS POTENTIAL FOR COMPROMISING BOTH COMFORT AND SAFETY IN THE INCREASING USE OF THE S-TURN, AND I FOR ONE AM GOING TO BE MORE CAUTIOUS ABOUT INITIATING OR ACCEPTING THIS MANEUVER.

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.