Narrative:

We were assigned the coney climb from lga with vectors to the eliot intersection. The procedure calls for a right turn after departure from runway 13 to a 180 degree heading to intercept the cri 043 degree radial; with a requirement to cross the lga 2.5 DME at or above 1500 ft. Because of climb requirement; my first officer and I went over the departure procedure carefully and we agreed that we would need to maintain the profile very closely to ensure that we met the climb restr. Per the performance data; the 13DP (for the coney climb) had an 'altitude-to' limit of 44237 pounds with no wind (accounting for the 1 KT headwind component -- the winds were 210 degrees at 6 KTS; would yield a slightly higher maximum takeoff weight of 44295 pounds). The temperature was 26 degrees per the ATIS. Our ramp weight was recorded at 42073 pounds; and our estimated takeoff weight was about 200 pounds less than that; at 41873 pounds. We departed lga using standard procedures; and the first officer did a solid rotation directly to the v-bars and very accurately flew the profile as we turned to 180 degrees. We crossed the lga 2.5 DME at 1040 ft; well short of the 1500 ft requirement. We crossed 1500 ft at roughly 2.9 DME; if memory serves. As we had specifically briefed the departure and had maintained the aircraft in very exacting compliance with our departure procedures; I believe that the performance numbers which would yield this climb performance required of the coney climb are inaccurate.

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Original NASA ASRS Text

Title: EMB145 FLT CREW CANNOT MEET CLB GRADIENT FOR LGA 9 DEP; CONEY CLB. CAPT BELIEVES PERFORMANCE REQUIREMENTS ARE INCORRECT.

Narrative: WE WERE ASSIGNED THE CONEY CLB FROM LGA WITH VECTORS TO THE ELIOT INTXN. THE PROC CALLS FOR A R TURN AFTER DEP FROM RWY 13 TO A 180 DEG HDG TO INTERCEPT THE CRI 043 DEG RADIAL; WITH A REQUIREMENT TO CROSS THE LGA 2.5 DME AT OR ABOVE 1500 FT. BECAUSE OF CLB REQUIREMENT; MY FO AND I WENT OVER THE DEP PROC CAREFULLY AND WE AGREED THAT WE WOULD NEED TO MAINTAIN THE PROFILE VERY CLOSELY TO ENSURE THAT WE MET THE CLB RESTR. PER THE PERFORMANCE DATA; THE 13DP (FOR THE CONEY CLB) HAD AN 'ALT-TO' LIMIT OF 44237 LBS WITH NO WIND (ACCOUNTING FOR THE 1 KT HEADWIND COMPONENT -- THE WINDS WERE 210 DEGS AT 6 KTS; WOULD YIELD A SLIGHTLY HIGHER MAX TKOF WT OF 44295 LBS). THE TEMP WAS 26 DEGS PER THE ATIS. OUR RAMP WT WAS RECORDED AT 42073 LBS; AND OUR ESTIMATED TKOF WT WAS ABOUT 200 LBS LESS THAN THAT; AT 41873 LBS. WE DEPARTED LGA USING STANDARD PROCS; AND THE FO DID A SOLID ROTATION DIRECTLY TO THE V-BARS AND VERY ACCURATELY FLEW THE PROFILE AS WE TURNED TO 180 DEGS. WE CROSSED THE LGA 2.5 DME AT 1040 FT; WELL SHORT OF THE 1500 FT REQUIREMENT. WE CROSSED 1500 FT AT ROUGHLY 2.9 DME; IF MEMORY SERVES. AS WE HAD SPECIFICALLY BRIEFED THE DEP AND HAD MAINTAINED THE ACFT IN VERY EXACTING COMPLIANCE WITH OUR DEP PROCS; I BELIEVE THAT THE PERFORMANCE NUMBERS WHICH WOULD YIELD THIS CLB PERFORMANCE REQUIRED OF THE CONEY CLB ARE INACCURATE.

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.