Narrative:

The controlling of my aircraft by norcal with respect to other arriving aircraft resulted in an unnecessarily demanding approach by this aviator. I would characterize our approach as minimally stabilized as a result of the controller's choices setting us up for this arrival. We were vectored from the sfo VOR on a 140 degree heading for the left downwind arrival at sfo. The weather was clear and the visibility at least 10 miles. We could have easily flown the approach over the bay with a right downwind. Over the coastal range; we were given a few vectors and incrementally descended with 1;000 foot clearances from 11;000 feet to 8;000 feet. We had briefed and were ready for the 28L visual approach we had also briefed the potential for a 28R approach. We were turned toward the final approach course; but not yet cleared for the visual. We told norcal we had the airport in sight. They asked if we had the B757 in sight who was at this time at our 4 to 5 O'clock position. We reported we did not have the traffic in sight. We are still at 8;000 feet while the B757 has been cleared to 4;000 feet. We are given vectors to incrementally fly towards the final approach course and are finally cleared for the visual approach for 28R. Norcal asked if we had the B757 in sight. The B757 was now at our 9 O'clock position about 2;500 to 3;000 feet below us. We reported the aircraft in sight. Of course; the next clearance was to not pass the B757 and to keep him in sight. At about 7;000 feet and about 4;000 feet above a normal glide path for the runway with power at idle and flaps at 20; we lowered the gear and extended the flaps to 25. We had briefed a 25 flap landing. The B757 was doing a good job not slowing too much for us and I have to thank that crew for their empathy for the situation we found ourselves in. Inside the bridge; to continue to stay behind the B757 and assure our potential for a landing; we extended flaps to 30 and flew the 30 ref speed as tight as possible since the wind had been reported as calm. We kept the B757 at least abeam our aircraft throughout the landing. I do not understand the rationale for this type of controlling. Why not put the heavier; higher aircraft on 28L while descending the aircraft for a normal glide path while slowing the lighter aircraft to remain behind the 400 while maneuvering it to land on 28R. Our controller obviously kept us high because he was positioning the B757 under us on his vectoring for 28L. There was minimal traffic arriving at that time of day. There was no reason to jam us together on the final approach courses for both runways while leaving the heavier aircraft so high on glide slope that a nearly power off; 30 flap landing was required from 8;000 feet to touchdown.

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Original NASA ASRS Text

Title: Air carrier inbound to SFO voiced concern regarding NORCAL handling during visual side-by approach procedures claiming ATC's instructions to follow a preceding B757 placed the reporters aircraft in an unstabilized profile.

Narrative: The controlling of my aircraft by NORCAL with respect to other arriving aircraft resulted in an unnecessarily demanding approach by this aviator. I would characterize our approach as minimally stabilized as a result of the Controller's choices setting us up for this arrival. We were vectored from the SFO VOR on a 140 degree heading for the left downwind arrival at SFO. The weather was clear and the visibility at least 10 miles. We could have easily flown the approach over the bay with a right downwind. Over the coastal range; we were given a few vectors and incrementally descended with 1;000 foot clearances from 11;000 feet to 8;000 feet. We had briefed and were ready for the 28L visual approach we had also briefed the potential for a 28R approach. We were turned toward the final approach course; but not yet cleared for the visual. We told NORCAL we had the airport in sight. They asked if we had the B757 in sight who was at this time at our 4 to 5 O'clock position. We reported we did not have the traffic in sight. We are still at 8;000 feet while the B757 has been cleared to 4;000 feet. We are given vectors to incrementally fly towards the final approach course and are finally cleared for the visual approach for 28R. NORCAL asked if we had the B757 in sight. The B757 was now at our 9 O'Clock position about 2;500 to 3;000 feet below us. We reported the aircraft in sight. Of course; the next clearance was to not pass the B757 and to keep him in sight. At about 7;000 feet and about 4;000 feet above a normal glide path for the runway with power at idle and flaps at 20; we lowered the gear and extended the flaps to 25. We had briefed a 25 flap landing. The B757 was doing a good job not slowing too much for us and I have to thank that crew for their empathy for the situation we found ourselves in. Inside the bridge; to continue to stay behind the B757 and assure our potential for a landing; we extended flaps to 30 and flew the 30 ref speed as tight as possible since the wind had been reported as calm. We kept the B757 at least abeam our aircraft throughout the landing. I do not understand the rationale for this type of controlling. Why not put the heavier; higher aircraft on 28L while descending the aircraft for a normal glide path while slowing the lighter aircraft to remain behind the 400 while maneuvering it to land on 28R. Our Controller obviously kept us high because he was positioning the B757 under us on his vectoring for 28L. There was minimal traffic arriving at that time of day. There was no reason to jam us together on the final approach courses for both runways while leaving the heavier aircraft so high on glide slope that a nearly power off; 30 flap landing was required from 8;000 feet to touchdown.

Data retrieved from NASA's ASRS site as of April 2012 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.