Narrative:

I would like to report on an ATC irregularity with reference to the dylin 2 arrival that could be a potential 'gotcha' for many a crew. Following the arrival procedure, the flight was assigned a speed of 290 KTS by ATC. The arrival requires you to cross somto intersection between 11000 and 12000 ft and the next step down is dylin at 8000 ft. The 'gotcha' is that you must be at 250 KTS at 10000 ft, then cross dylin at 8000 ft with only 13 mi to do it (no wind). We crossed somto at 11000 ft, but slowing to 250 KTS by 10000 ft and meeting the crossing restr at dylin at 8000 ft proved to be unattainable due the performance capabilities of the B737-800, even with the spoilers fully deployed in the flight position. This attempt was further complicated by a request to expedite down to 8000 ft by ATC. I subsequently came through 10000 ft higher than 250 KTS and above 8000 ft at dylin. Descent and speed control planning was distracted by ATC talk of holding going into ewr and we were thinking we might hold at ard (yardley). ATC did not indicate there were any conflicts and asked to do the best you can. In hindsight, clarification with ATC about the speed, slowing sooner and better descent planning would have made the speed and altitude restr an attainable target. I hope pointing this out helps. Callback conversation with reporter revealed the following information: reporter stated that he felt that the acceptance of the faster airspeed issued by ATC was the main factor that contributed to missing the crossing restrs. When queried by the analyst about accepting the higher airspeed, he indicated that they could have refused it due to aircraft performance. Report was mainly submitted as a 'heads up' for other flight crews to be aware that the arrival requires extra vigilance.

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Original NASA ASRS Text

Title: B737 FLT CREW IS UNABLE TO MEET THE XING RESTRS DEPICTED ON THE ARR INTO EWR.

Narrative: I WOULD LIKE TO RPT ON AN ATC IRREGULARITY WITH REF TO THE DYLIN 2 ARR THAT COULD BE A POTENTIAL 'GOTCHA' FOR MANY A CREW. FOLLOWING THE ARR PROC, THE FLT WAS ASSIGNED A SPD OF 290 KTS BY ATC. THE ARR REQUIRES YOU TO CROSS SOMTO INTXN BTWN 11000 AND 12000 FT AND THE NEXT STEP DOWN IS DYLIN AT 8000 FT. THE 'GOTCHA' IS THAT YOU MUST BE AT 250 KTS AT 10000 FT, THEN CROSS DYLIN AT 8000 FT WITH ONLY 13 MI TO DO IT (NO WIND). WE CROSSED SOMTO AT 11000 FT, BUT SLOWING TO 250 KTS BY 10000 FT AND MEETING THE XING RESTR AT DYLIN AT 8000 FT PROVED TO BE UNATTAINABLE DUE THE PERFORMANCE CAPABILITIES OF THE B737-800, EVEN WITH THE SPOILERS FULLY DEPLOYED IN THE FLT POS. THIS ATTEMPT WAS FURTHER COMPLICATED BY A REQUEST TO EXPEDITE DOWN TO 8000 FT BY ATC. I SUBSEQUENTLY CAME THROUGH 10000 FT HIGHER THAN 250 KTS AND ABOVE 8000 FT AT DYLIN. DSCNT AND SPD CTL PLANNING WAS DISTRACTED BY ATC TALK OF HOLDING GOING INTO EWR AND WE WERE THINKING WE MIGHT HOLD AT ARD (YARDLEY). ATC DID NOT INDICATE THERE WERE ANY CONFLICTS AND ASKED TO DO THE BEST YOU CAN. IN HINDSIGHT, CLARIFICATION WITH ATC ABOUT THE SPD, SLOWING SOONER AND BETTER DSCNT PLANNING WOULD HAVE MADE THE SPD AND ALT RESTR AN ATTAINABLE TARGET. I HOPE POINTING THIS OUT HELPS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT HE FELT THAT THE ACCEPTANCE OF THE FASTER AIRSPD ISSUED BY ATC WAS THE MAIN FACTOR THAT CONTRIBUTED TO MISSING THE XING RESTRS. WHEN QUERIED BY THE ANALYST ABOUT ACCEPTING THE HIGHER AIRSPD, HE INDICATED THAT THEY COULD HAVE REFUSED IT DUE TO ACFT PERFORMANCE. RPT WAS MAINLY SUBMITTED AS A 'HEADS UP' FOR OTHER FLT CREWS TO BE AWARE THAT THE ARR REQUIRES EXTRA VIGILANCE.

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.