B737 flight crew departed ont on the prado departure and was cleared to 6;000. The next controller g...

Narrative:

Our takeoff altitude limit was changed from 7;000 feet as per the pre departure clearance (pre departure clearance) to 'climb and maintain 3;000'' after takeoff. We took off; I was flying; and then we received a clearance from departure control to climb to 4;000 feet. Then we were given a climb to 6;000 feet. I did notice multiple TCAS targets in the area. Then we were given a controller change. He called us without us checking-in and gave us an immediate descent to 4;000 feet. I reacted quickly to initiate a descent to 4;000 feet. Passing around 5;000-5;500 feet; we received a significant climb RA opposite of what ATC was telling us to do. Again; I reacted promptly to initiate and follow the climb RA as instructed and taught to do so. I followed the TCAS RA advisory until 'clear of conflict' was heard and a climb to 14;000 feet was given to us by ATC. I have always been taught to follow a TCAS RA instructions. That is great technology; and the rest of the flight was uneventful.perhaps change the departure procedure out of ontario; or have the airspace more clear through that valley on the prado. There were a lot of VFR targets. Maybe even a VFR corridor.

Original NASA ASRS Text

Title: B737 flight crew departed ONT on the PRADO departure and was cleared to 6;000. The next Controller gave them an immediate descent to 4;000 feet and the climb was reversed just as the TCAS issued a climb RA which was complied with.

Narrative: Our takeoff altitude limit was changed from 7;000 feet as per the Pre Departure Clearance (PDC) to 'climb and maintain 3;000'' after takeoff. We took off; I was flying; and then we received a clearance from Departure Control to climb to 4;000 feet. Then we were given a climb to 6;000 feet. I did notice multiple TCAS targets in the area. Then we were given a Controller change. He called us without us checking-in and gave us an immediate descent to 4;000 feet. I reacted quickly to initiate a descent to 4;000 feet. Passing around 5;000-5;500 feet; we received a significant climb RA opposite of what ATC was telling us to do. Again; I reacted promptly to initiate and follow the climb RA as instructed and taught to do so. I followed the TCAS RA advisory until 'Clear of Conflict' was heard and a climb to 14;000 feet was given to us by ATC. I have always been taught to follow a TCAS RA instructions. That is great technology; and the rest of the flight was uneventful.Perhaps change the departure procedure out of Ontario; or have the airspace more clear through that valley on the PRADO. There were a lot of VFR targets. Maybe even a VFR corridor.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1320975
Time
Date	201512
Local Time Of Day	1201-1800
Place
Locale Reference	ONT.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737 Next Generation Undifferentiated
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	SID PRDO8
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 218
Person 2
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

B737 flight crew departed ont on the prado departure and was cleared to 6;000. The next controller gave them an immediate descent to 4;000 feet and the climb was reversed just as the TCAS issued a climb RA which was complied with.