Narrative:

During our cockpit preparation for our flight, we carefully reviewed the departure SID procedure because of its complexity. Our ATC clearance was to fly the prado two departure and maintain 7000', thermal transition. During taxi out we noticed a sign on the right side of taxiway north just prior to the departure end of runway 26R which says 'for noise abatement, prado two departure, no turn below 2 thousand feet'. We queried ont tower as to why this restriction is not a part of the SID. The reply was that the 2 thousand foot restriction is part of the 'informal' noise abatement policy at ont and that they would appreciate our compliance. We said that we would comply. After takeoff clearance was received and acknowledged, and during our takeoff roll, at about 80 KTS, we were told to 'maintain 4 thousand.' we acknowledged the restriction although it was given at an awkward time. As we continued our takeoff and after we passed through 2 thousand feet MSL we started a left turn to our assigned heading of 210 degree. Shortly after we initiated our turn, and after our initial contact with departure control, we were told to 'maintain 3500' for traffic'. Our rate of climb at this point was about 1500 FPM and we were preparing to level off at 4000'. We had to abruptly level the aircraft to maintain 3500'. After my heart rate slowed to normal, I asked the controller why the sudden level off. He responded that he had expected us to start our turn sooner. It appears as if the right hand (local noise abatement policy) doesn't know what the left hand, (ATC departure procedure) is doing.

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Original NASA ASRS Text

Title: SIGN BY TKOF RWY, NO TURNS BELOW 2000, IS IN CONFLICT WITH DEP CTLR CLRNC.

Narrative: DURING OUR COCKPIT PREPARATION FOR OUR FLT, WE CAREFULLY REVIEWED THE DEP SID PROC BECAUSE OF ITS COMPLEXITY. OUR ATC CLRNC WAS TO FLY THE PRADO TWO DEP AND MAINTAIN 7000', THERMAL TRANSITION. DURING TAXI OUT WE NOTICED A SIGN ON THE RIGHT SIDE OF TXWY N JUST PRIOR TO THE DEP END OF RWY 26R WHICH SAYS 'FOR NOISE ABATEMENT, PRADO TWO DEP, NO TURN BELOW 2 THOUSAND FEET'. WE QUERIED ONT TWR AS TO WHY THIS RESTRICTION IS NOT A PART OF THE SID. THE REPLY WAS THAT THE 2 THOUSAND FOOT RESTRICTION IS PART OF THE 'INFORMAL' NOISE ABATEMENT POLICY AT ONT AND THAT THEY WOULD APPRECIATE OUR COMPLIANCE. WE SAID THAT WE WOULD COMPLY. AFTER TKOF CLRNC WAS RECEIVED AND ACKNOWLEDGED, AND DURING OUR TKOF ROLL, AT ABOUT 80 KTS, WE WERE TOLD TO 'MAINTAIN 4 THOUSAND.' WE ACKNOWLEDGED THE RESTRICTION ALTHOUGH IT WAS GIVEN AT AN AWKWARD TIME. AS WE CONTINUED OUR TKOF AND AFTER WE PASSED THROUGH 2 THOUSAND FEET MSL WE STARTED A LEFT TURN TO OUR ASSIGNED HDG OF 210 DEG. SHORTLY AFTER WE INITIATED OUR TURN, AND AFTER OUR INITIAL CONTACT WITH DEP CTL, WE WERE TOLD TO 'MAINTAIN 3500' FOR TFC'. OUR RATE OF CLIMB AT THIS POINT WAS ABOUT 1500 FPM AND WE WERE PREPARING TO LEVEL OFF AT 4000'. WE HAD TO ABRUPTLY LEVEL THE ACFT TO MAINTAIN 3500'. AFTER MY HEART RATE SLOWED TO NORMAL, I ASKED THE CTLR WHY THE SUDDEN LEVEL OFF. HE RESPONDED THAT HE HAD EXPECTED US TO START OUR TURN SOONER. IT APPEARS AS IF THE RIGHT HAND (LOCAL NOISE ABATEMENT POLICY) DOESN'T KNOW WHAT THE LEFT HAND, (ATC DEP PROC) IS DOING.

Data retrieved from NASA's ASRS site as of August 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.